Vrayc4d Manual 1 1

8/6/2019 Vrayc4d Manual 1 1

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VRAYforC4D Manual - table of contents

Manual Version 1.1 written by Stefan LAUB / Updated by Anton Goroh (aka Tong) / Last update: 11.11.2008*

TERMS OF CONDITION............................................................................................................... 3

Change Log ..............................................................................................................................6

VRAYforC4D Features .............................................................................................................. 10

About Info.............................................................................................................................. 11

Activating VrayforC4D.............................................................................................................. 14

Overview................................................................................................................................ 17

Render SettingsOptions .................................................................................................................................. 24Image Sampler (Antia-aliasing)................................................................................................. 27DMC sampler.......................................................................................................................... 31

Indirect Illumination (GI) ......................................................................................................... 33Brute force GI......................................................................................................................... 39Irradiance map ....................................................................................................................... 40Photon mapping...................................................................................................................... 47Light cache............................................................................................................................. 50Combining GI Methods............................................................................................................. 55Caustics................................................................................................................................. 57Displacement.......................................................................................................................... 59Environment........................................................................................................................... 60Color Mapping......................................................................................................................... 63Vray Camera .......................................................................................................................... 65System.................................................................................................................................. 68MultiPass................................................................................................................................ 71Camera Clipper....................................................................................................................... 72

MaterialsMaterial Layered Channels........................................................................................................ 73Matte Layer............................................................................................................................ 75Material Weight....................................................................................................................... 76Bump .................................................................................................................................... 77Luminosity Layers ................................................................................................................... 79Reflection Layer ......................................................................................................................81Specular Layers ......................................................................................................................83Diffuse Layers......................................................................................................................... 87Refraction Layer...................................................................................................................... 89

Cinema4d Shaders .................................................................................................................. 92Assigment ..............................................................................................................................93

Vray2SideMaterial ................................................................................................................... 94

VrayBlendMaterial ................................................................................................................... 96

VrayDisplaceMaterial ............................................................................................................... 98Displacement Tag.................................................................................................................. 100

Vray OverrideMaterial............................................................................................................ 102

Vray Compositing Tag............................................................................................................ 104

VRay Motion Blur Tag ............................................................................................................ 107


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Vray Material Converter ......................................................................................................... 108

Vray LightsVRayLight parameters............................................................................................................ 109Vray Light - Common Tab ...................................................................................................... 110Vray Light - Spot light............................................................................................................ 113Vray Light - Area light............................................................................................................ 114Vray Light - Sun light............................................................................................................. 116

Vray Light - IES Light ............................................................................................................ 118

VRay Physical Camera ........................................................................................................... 120

VRay Camera Dome .............................................................................................................. 123

Vray Proxy ........................................................................................................................... 124

Vrmesh Exporter Tag............................................................................................................. 127

VRAYforC4D Professional Render system for Maxon Cinema4D and Bodypait 3d Products. On OSX Intel 10.4.10 or WinXP SP2. For Cinema versions 9.6 & 10.1+.Vray system based on the 1.5.0 SDK provided by Chaosgroup. V 1.0 Released on 17.09.2007. Cinema 4D is a registered trademarks of Maxon Computer(www.maxon.net) , VRAYforC4D software, VRAYforC4D logo and VRAYforC4D documentation belong to LAUBlab_Vienna (in Cooperation with Renato Tarabella and

Daniele Ficini). V-Ray belongs to Chaosgroup (www.chaosgroup.com)All other brand names, product names, or trademarks belong to their respective holders.
http://www.maxon.net%29/http://www.chaosgroup.com%29/http://www.chaosgroup.com%29/http://www.maxon.net%29/


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TERMS OF CONDITION

VRAYFORC4D Software License Agreement:

IMPORTANT - READ CAREFULLY: By accepting this software, you agree to be bound by theterms and conditions of this License Agreement. These are the only terms upon whichVRAYFORC4D is licensed.

Grant of LicenseVRAYFORC4D /LAUBlab (The Company) is empowered, and has agreed in consideration of the paymentby you of the license fee hereunder to grant you a personal non-exclusive, non-transferable limitedlicense to use the enclosed program (the software or V-RAY or VRAYFORC4D) in accordance with theterms and conditions of this Agreement. This License agreement permits a single user to use theSoftwares user interface on only one computer at one location at any one time; use up to 10 runningcopies of the Software for distributed rendering at any one time; use unlimited number of runningcopies for network (frame-by-frame) rendering.

Interpretation & DefinitionsIn this Agreement unless the context otherwise requires:

Documentation means the technical manuals, user manual and other information which is being madeavailable by the Company to you in either printed or machine readable form;

Intellectual Property Rights means any and all patents, registered trademarks, registered designs,application for any of the foregoing, trade and business names, unregistered trademarks, logos, know-how, trade secrets, copyrights, rights in designs, inventions, rights under licenses and consents inrelation to any such rights and rights of the same on similar effect or nature in relation to software,source code, object code and associated documentation, together with all goodwill whether or not

attaching or relating thereto, in any part of the world.

VRAYFORC4D means the VRAYforC4D rendering plugin connection to the V-RAY Render engine 1.6(SDK) from Chaos group ltd. for MAXON Cinema 4D v9.6 and v10.+

Use shall mean the right of you to design, create and test your own works (User Works) usingVRAYforC4D; distribute your User Works to End users; make back up copies of VRAYforC4D. You maymodify and make unlimited copies of any resulting animations, still images or scene files contained inthe Software PROVIDED THATyou shall indemnify, hold harmless and defend the Company against anyand all costs, claims, demands, expenses, losses and liabilities of whatsoever nature which may arisein conjunction with the distribution or use of your User Works and copies of files contained in theSoftware.

Property and confidentiality in VRAYforC4DVRAYforC4D and the Documentation shall remain the sole and exclusive property of the Company.Nothing in this Agreement shall confer any rights in any trade name, business name or trademark ofthe Company on you.

In order to properly authorize the VRAYforC4D software, the Company may obtain certain informationabout the users computer system through the VRAYforC4D license request code. The Companyunderstands that this information may be sensible and shall consider it as confidential. The Companyguarantees that this information will be used only internally and in order to prevent illegal use of theSoftware. The Company also guarantees that it will use its best commercially reasonable efforts toprotect this information except in cases where this information might be required by applicable law.

Restrictions


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Save as otherwise expressly set out herein or as otherwise expressly permitted by law, you shall not:

(a) Make any translation, adaptation, arrangement and any other alteration of the VRAYforC4Dsoftware or make any reproduction, distribution, communication, display or performance to the publicof the results of such acts;

(b) Adapt or reverse compile or engineer the whole or any part of VRAYforC4D.

(c) Assign, transfer, sell, lease, rent, charge or otherwise deal in or encumber VRAYforC4D or use

VRAYforC4D on behalf of any third party, or make available the same to any third party without theprior written consent of the Company;

(d) Remove or alter any copyright or other proprietary notice from VRAYforC4D;

(e) Not by itself or with others participate in any illegal, deceptive, misleading or unethical practicesincluding, but not limited to, disparagement of VRAYforC4D or the Company or other practices whichmay be detrimental to VRAYforC4D or the Company;

(f) Notify the Company immediately if you becomes aware of any unauthorized use of the whole or anypart of VRAYforC4D by any third party;

WarrantyTHE COMPANY DOES NOT WARRANT THAT THE USE OF VRAYforC4D WILL MEET YOURREQUIREMENTS, OR THAT THE OPERATION OF VRAYforC4D WILL BE UNINTERRUPTED OR ERRORFREE. THE COMPANY DOES NOT WARRANT THE ACCURACY OR COMPLETENESS OF THE DATACONTAINED IN VRAYforC4D. THE COMPANY DOES NOT WARRANT THE ACCURACY OF THECOMPUTATIONS CARRIED OUT BY VRAYforC4D DURING ITS OPERATION AND SPECIFICALLY DOESNOT WARRANT ITS USE IN SAFETY CRITICAL APPLICATIONS. SUBJECT TO THE FOREGOING ALLCONDITIONS, WARRANTIES, TERMS AND UNDERTAKINGS EXPRESS OR IMPLIED STATUTORY OROTHERWISE IN RESPECT OF VRAYforC4D AND THE DOCUMENTATION ARE HEREBY EXCLUDED TO THEGREATEST EXTENT PERMISSIBLE BY APPLICABLE LAW.

Limitation of liability & RemediesSubject to the limits set out below, the Company shall accept liability to you in respect of direct dam-age to tangible property resulting from the negligence of the Company or its employees agents or sub-contractors. The Companys entire liability in respect of any Event of Default shall be limited todamages of an amount equal to the amount of the initial purchase price originally paid by you for theSoftware. The Company shall not be liable to you in respect of any Event of Default for loss of data,information, profits or goodwill (whether such loss is direct or indirect) or any type of special indirect orconsequential loss (including loss or damage suffered by you as a result of an action brought by a thirdparty) even if such loss was reasonably foreseeable or the Company had been advised of the possibilityof you incurring the same. If a number of Events of Default give rise substantially to the same lossthen they shall be regarded as giving rise to only one claim under this Agreement. The En- tire Liabilityof the Company and your exclusive remedy under the warranty provided herein will be to attempt tocorrect or work around errors, to replace the Software or to refund the purchase price and terminatethis Agreement. This remedy is subject to return of the Software to the Company.

IndemnitiesYou shall indemnify the Company, and keep the Company fully and effectively indemnified on demandfrom and against any and all losses, claims, damages, costs, charges, expenses, liabilities, demands,proceedings and actions which the Company may sustain or incur, or which may be brought orestablished against the Company by any person, which in any case arise out of or in relation to, or byreason of:- any breach by you of your obligations under this Agreement; any alteration, modification,adjustment or enhancement made by you to VRAYforC4D; or any combination, connection, operationor use of VRAYforC4D with any other equipment, software or documentation not supplied by the

Company.


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TerminationThis License is effective until terminated. You may terminate this License at any time by destroying theSoftware, related documentation and all copies thereof. This license will terminate immediately withoutnotice from the authorized publisher if you fail to comply with any provision of this License. Upontermination you must destroy the Software and related documentation and all copies thereof.

Entire AgreementThe Company shall not be liable to you for loss arising from or in connection with any representations,agreements, statements or undertakings made prior to the date of execution of this Agreement otherthan those representations, agreements, statements or undertakings confirmed by a duly authorizedrepresentative of the Company in writing or expressly incorporated or referred to in this Agreement.

LawAny controversy, claim or dispute that cannot be so resolved shall be settled by final bindingarbitration in accordance with the rules of the World Arbitration Association, and judgment upon theaward rendered by the arbitrator or arbitrators may be entered in any court having jurisdiction thereof.Any such arbitration shall be conducted in the city where the Companys headquarters are located (A-1040 Vienna, Austria).

Cinema 4s is a registered trademarks of Maxon Computer (www.maxon.net), VRAYforC4D software, VRAYforC4D logo and VRAYforC4Ddocumentation belong to LAUBlab_Vienna (in Cooperation with Renato Tarabella). V-Ray belongs to Chaos group (www.chaosgroup.com) All otherbrand names, product names, or trademarks belong to their respective holders.
http://www.maxon.net%29/http://www.maxon.net%29/http://www.chaosgroup.com%29/http://www.chaosgroup.com%29/http://www.maxon.net%29/


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Change Log

Change Log

VRAYforC4D Version 1.1

Bugs Fixes

Fixed Global Option to disable lights doesn't work Fixed Global Option to disable shadows (didn't work for the Physical Sun) Fixed Global Option to disable displacement doesn't work Fixed Light Dome HDRI texture mapping crash Fixed Incorrect sampling for the irradiance map when the "Adaptation only" option for the color

mapping is on Fixed Incorrect render progress report with light cache

Fixed Incorrect behaviour of Region render option in the VrayBridge panel Fixed UV offsets ghosted in every Environment setting if Frontal mapping used in Background Fixed Vray tags problems with some modelling tools like "Stich and Sew" and "Bridge" Fixed Light Cache calculation when used in flythrough mode Fixed Textures multipliers and mix mode not working properly Fixed Displacement not working properly with UVW projection Fixed Black background rotating the material preview scene Fixed Decals not working with stacked materials (just use in the material weight a plain 24 bit,

without alpha, black and white texture as alpha) Fixed SSS when used with the Diffuse2 layer

Changes

Bucket method set to triangulation as default Affect shadow in Refraction Layer set to on by default All new way to save GI and Caustics calculation files. Now just choose the filename, no need for the

extension (it will be automatically added as irMap or lcMap or phMap or caMap). Just remember to doa save project before to save these files.

Vignetting parameter in VrayPhysicalCamera is now adjustable from 0 to 1.

Enhancement

Improved sampling in the DMC sampler

Improved handling of smoothed normals at grazing camera angles; Enabled values above 1 for the Volume Amount under the Refraction layer of the Vraymaterial The ISO setting in the VrayPhysicalCamera tag can now be set higher than 1600 The handles for Area lights and Spot Lights can now be manipulated from the viewport Impressive speed-up in exporting scenes with a lot of objects. Now you can export 20.000 objects in

few seconds.

New Features

Added VrayBridge 64bit Added Native Cinema4D Materials support (reflection and refraction channels don't work) Added Vray2SidedMaterial Added VrayBlendMaterial (you can now stack materials on polygon selections) Added MaterialMatte option in VrayMaterial Added "Soft Edges" option in VrayMaterial under Specular Layers


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Added New Antialiasing FIlter (Area, Catmull, Gaussian) and enhanced some of the old ones Added Default surface color Option when object has no material Added Full "Material Override" Added "Min paths per samples" for the light cache computation Added "Override LC subdivision" option for the light cache computation (with, relative to image size,

7 step sample/ratio) Added All new OpenGL materials preview Added "Object Visibility" option (animatable) to VrayCompositing tag Added "Vertical Split" (act as default option) for Split/Region under the Vray System tab of the

VrayBridge panel Added Options in the VrayLight tag under the SunLight tab so Physical Sky doesn't override

Environment options Added Option to in the VrayBridge panel under the Environment tab to enable/disable the way BG

Env affect GI Env. Added White Balance presets to the VrayPhysicalCamera tag Added Fixed exposure increments for F-stop, Shutter speed and ISO Added Store current exposure to compensate for motionblur or dof effects (and mantain correct

exposure) Added Object ID parameter in the VrayCompositing tag for Multipass Added Generate/Recieve GI and Caustics in the VrayCompositing tag Added VrayDisplaceMaterial to replace the now old VrayDisplacement tag Added VrayCamera and VrayPhysicalCamera MotionBlur Added Object MotionBlur, also full Rotational MB (for non-deformed objects only at the moment) Added RGB displacement Added Scene units now selectable from the VrayBridge Panel Added Photometric light scale parameter to compensate exposure for non physical camera renders Added On rendering Subdivision surfaces render (using the VrayDisplaceMaterial) Added VrayProxy support, also with auto generating proxy objects. Added Normal map support to the Bump layer in the VrayMaterial Added Roughness parameter to the Diffuse Layer of the VrayMaterial Added Sky Intensity Multiplier parameter to the Physical Sky Added Affect Diffuse/Specular/Reflections for lights (Affect Reflections only with the VrayLight tag)


Bugs Fixes

Fixed Infinity light smooth shadows bug. Fixed the problem that save uncompleted frames.

Enhancement

Parallel/perspective rendering Viewport correct. Much faster buckets redraw. New installer for Windows and Osx.

New Features

Added Physical Camera support in perspective Viewport not associated with a camera. Added Sun intensity parameters for both the Physical and Standard Camera (the renderer choose it

automatically). Added Options to override Cinema Field of View to support FOV from 0 to 360 degree. Added Frontal projection map for the Environment maps.

VRAYforC4D Version 1.0821 Some little entrenchments inside and the compatibility with Xp64.


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Bugs Fixes

Fixed Distance threshold bug in Irradiance Map Fixed Filter on/off bug Fixed Light Dome Photon emit radius

Fixed Cinema 4D R10.5 VrayBridge panels scaling bug

Changes

Changed Color Mapping nomenclature Changed some default values Number of passes in LC now defaults to CPU number

New Features

Added native Vray Multipass render

Added VrayCameraDome tag Added Override Material in global option Added Camera Clipping Planes Added Camera Geometry Clipper Added Clamp level parameter in Color Mapping Added Light Dome rotations Added Environment U and V offsets Added Specular Anisotropy textures Added some options in the stamp rendering informations


Fixed Infinite light behavior, now can effectively use the intensity parameter both from Cinema's lightpanel and the VrayLight tag.


Bugs Fixes

Fixed Photometric lights (now there's perfect values conversion from the various photometric units)for even more realistic light diffusion.

Fixed Spot light cone angle and penumbra angle to conform to Cinema spot light render Fixed multiple render settings bug

New Features

Added Shadow color parameter in the VrayLight tag

VRAYforC4D Version 1.03 Fixed the bug on the DMC AA that always set to 0.0 the threshold.


Bugs Fixes


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Fixed Alpha support for textures.

Enhancement

New Fine tuned GI Presets. Changed the Illumination Panel in the VrayMaterial in "OGL Textures" (the unuseful Cinema GI

settings are gone).

New Features

Added Hair polygon shader support (from Hair module) Added Adaptive DMC Threshold parameter in the VrayBridge Antialiasing panel. Added Adaptation Only option in the VrayBridge Color Mapping panel. Added Color coded icon to better visualize the VrayBridge tags

VRAYforC4D Version 1.01 Net render now is working good Corrected the behavior of the light when using the photometric units


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VRAYforC4D Features

VRAYforC4D Features

The VRAYforC4D rendering system has many advanced features; here only some of them are listed.For a full list of all VRAYforC4D modules and options, please see the help index. Note that all featuresare subject to change without special notice. All VRAYforC4D changes for that moment you can seehere.

Full Vray 1.6 core standalone integration in to Cinema4D Windows and OSX versions 32bit and 64bit versions Unlimited Cinema4D NET Render support per one license. Efficient shading system specifically optimized for ray-tracing Fully multithreaded, even in material preview. Supports unlimited cpu`s and cores per workstation, scales extreme on multi core machines Efficient geometry handling True instance rendering On-demand dynamic geometry creation On-demand geometry loading from disk files Displacement mapping Three different image sampling methods Full-scene antialiasing Progressive path tracing Support for additional render elements (diffuse, reflection, GI etc) Advanced color (tone) mapping controls Physically accurate full global illumination solutions Different GI algorithms: path tracing, irradiance cache, photon maps, light cache Reusable GI solutions for accelerated rendering of walk-through animations and animations with

dynamic objects Physically accurate area lights Compatible with IES lights Efficient illumination from HDR environments Physical sun & sky Complete support of Cinema4D shaders Physically plausible materials Blurry reflections/refractions Accurate highlights Sub-surface scattering Support for efficient material layering Real Microdisplacement Depth-of-field with bokeh effects Accurate motion blur Physical camera Multipass render Compositing tag support Camera Clipper Vray Proxy support Volume Lights support HAIR module of Cinema4D supported Xref support in 10.5


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About Info

About Info

About Vray

Vray is one of the very high end available render systems out there. Almost the whole architecturalVisualization business changed to Vray over the last years and the trend is ongoing, but not onlyarchitects, also product designer and other areas jumped on the train. After its enormous success onthe market V-Ray has become also the renderer of choice in big production studios across the world.Feature film productions, multi-million dollar game productions have trusted their visuals to V-Ray.The huge success of Vray might be a combination of wonderful GI light-distribution at unbeaten speed(also for GI animation), solid, high quality shaders, very nice antialiasing and a very intelligent but yeteasy workflow. its is also a very, very stable application.

For those who don`t want long explanations, here also a short description;-) :

Its good

its fast

its stable.

About Manual

This Manual is the first incarnation. We will improve and expand it regularly.

If there is any information you cant find please use the official vrayforc4d forum or unofficial vrayc4d

site ;-). We try to answer it there. But please read the manual before thoroughly;-) As a secondtraining and learning option we also offer some on-line videos to show you how to start in VRAYforC4D.

As for the language please consider we are no native English speakers, there might be errors in it, butwe hope you understand all parts. For the first version the Manual is in English only, if the demand ishigh we might let localize it for certain languages. If you found any errors in manual, please send emailto [email protected], thank you.

The manual will not cover the c4d specific workflow, please use the Cinema4d documentation fromMaxon for c4d related aspects. We assume that you have basic knowledge of cinema 4d already.

About UsWe are a very small but efficient development team of people, - C4d Users and Programmers. We areresponsible for the planning, conception, programming and marketing of VRAYforC4D.

The Project is lead by C4d User and Architect Stefan Laub, the programming itself is lead by RenatoTarabella with Daniele Ficini as our render and shader developer specialist, without his great help theproject would not have developed in such a great way. Also we have very good group of beta testers,who also helps us very much to make vrayc4d best render engine for Cinema4D ever.

The VRAYforC4D team are responsible for all parts of the VRAYforC4d plugin.

For the rendercore of Vray (Vray SDK 1.6) Chaosgroup is held responsible, for all parts regardingCinema4d or Bodypaint3D Maxon Computer is held responsible.
mailto:[email protected]:[email protected]


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A big Thank goes to Vlado from Chaosgroup, without him this project would not exist, and also toMaxon Computer for providing us with internal information and help to make to most deep integrationinto Cinema 4d!

The project is initiated & owned by LAUBlab_KG (www.laublab.com ) placed in Vienna, Austria. It isproduced in partnership with Renato Tarabella (www.tarabella.it) and Daniele Ficini(www.danieleficini.com)

We hope the Users will have as much fun as we have with vrayforc4d:-)

With Best Greetings from Stefan, Renato, Daniele and all members of VRAYforC4D team.

About the project VRAYforC4D

As a C4D users ourselves we were wishing for the great Vray Render engine to be available for ourpreferred platform Maxon Cinema 4D & Bodypaint 3D.

We hoped that some higher authority will start to do THE thing. Nothing happened. So after oneand a half year of waiting Stefan decided something had to be done...after several calls to Maxon, toChaosgroup and some emails to Vlado the agreements where fixed, VRAYforC4D as born.

We teamed up with the well-known cinema4d plugin programmer Renato Tarabella, to be sure qualityis on our side...

Both Maxon and Vlado promised us help as much as possible with the sdk, shaders etc...

Vlado nicely provided us with the up to date sdk of Vray, so we use the same render core as Vray for3d Max.

We initially planned to make a raw exporter plugin bridge to the Vray standalone, also we decided tomake an open development, so we made our development plan public very early the worldwidereaction was overwhelming and many users supported us with they preorder emails from around the

world.

Due to this heavy demand we decided to expand the project to become a fully integrated rendersolution for Cinema4d, also we decided to make not a clone of 3DMax Vray, but to make a very C4D-native Vray version, to combine the best from both worlds.

To have a render system that uses the ultimate render quality and speed of Vray along with Cinema4Dgreat Interface, easy of use, and last not least the well known and mighty c4d procedural, layeredshader system, we support almost all native c4d shaders and even most 3rd party shader pluginsalready in first release!

So after 14th month of development we are very proud to present a very high grade professional

render system, that supports already in version 1.0 most aspects of vray for 3dmax that needed yearsto develop (see also vrayforc4d feature list for all details). The already planned updates will adds inaddition to the NETRender support the Vray DR - distributed rendering, Vray Proxies, and the vrayshaders in addition to the c4d shading system, among other new not yet announced vray features.

The VRAYforC4D engine will get regular updates and will expand even further. Our goal is to deliverone of the best Vray platforms available.

About software development

Our goal was to make a really stable software that meets the well known stability of Maxon Cinema4d.

Already version 1.0 proved to be extreme stable in testing thanks to the well programming of RenatoTarabella, Daniele Ficini and of course Vlado from Chaosgroup. The Combination of Vray + Cinema4Dmight be already the most stable vray render environment available today.
http://www.laublab.com/http://www.tarabella.it/http://www.tarabella.it/http://www.danieleficini.com/http://www.danieleficini.com/http://www.tarabella.it/http://www.laublab.com/


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Many professional beta testers worldwide tested all stages of the development, also a big Thank Youto all our great beta testers we have!

So will the software have bugs? - Yes of course, if someone is honest we have to realize that there isno software without bugs out there.

But we are confident that we have rather few for a version 1.0, we tried to minimize them as much aspossible, and even more important we are committed to react fast on any possibly found bugs and fix

them as fast as we can, there is the official vrayforc4d forum (www.vrayforc4d.com/forum, where youcan post any bugs, irregularities, feature wishes or suggestion to us:-)

LAUBlab and the developers will be there regularly and check and answer your posts.

How about updates? We will already plan the next version of Vray and we will also incorporate allfuture Vray core updates made by Chaosgroup and/or Maxon to keep VRAYforC4D on most recentstandards and compatible with the newest Cinema versions.

Furthermore we will expand the VrayforC4d to become even more advanced and versatile, we want tohave and keep it one the best renderengine available for Cinema4d. We see the Vray future very bright:-)

Notes We can only give an estimation on future updates, as some parts depend on Maxon & Chaosgroup

sdk, so features of version 1.1.x & 1.2 are subject to change, check the www.vrayforc4d.comwebpage for recent news.
http://www.vrayforc4d.com/forumhttp://www.vrayforc4d.com/http://www.vrayforc4d.com/http://www.vrayforc4d.com/forum


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Activating VrayforC4D

Activating VrayforC4D

Very important User information

After payment You have to send Your first 11 digits of Cinema4D Serial Number [email protected] along with your full name, address, phone number and a valid email addressto get the license key file, to receive the installation files, and to registered as valid user in ourdatabase, if any part of this is missing we cannot process your license!

Important: in any case you have to register with this data at [email protected] your license will not be valid and you are not legible for future updates. Even ifyou get some or all parts of the software and/or a license key file already, but forget toregister at [email protected], your license will not be legal!

Once you are registered you get a registration email from [email protected] with a personal

code. Print and keep this email at a save place. without this confirmation of registration you will not beable to get future updates and your license will expire.

Due to the massive spam mails these times in email we have to introduce some rules with emailcommunication: it is quite easy if you follow these guide lines the emais will be read by us: you mustuse the word "vray" in the title of the email. all emails that have no "vray" in title will be filtered, wehope you understand this, it is to make a better communication with our users possible, if for any casethe mail contact doesn't work, feel free to call us by phone, the number you find also in our website,we are normally reachable from monday to friday from 9h to 18h european time.

Installation Instructions

For installation please read the read me.txt file provided in the installation folder. Follow theinstructions carefully, otherwise the product will not run correct or will be unstable.If you need help for installation please visit the official VRAYForC4D Web Forum underwww.vrayforc4d.com/forum

Activation within Cinema 4d 10

After installation you can activate VRAYforC4D as renderengine under:Render settings tab - Effects tab : Add effect Vraybridge.
mailto:[email protected]:[email protected]:[email protected]:[email protected]://www.vrayforc4d.com/forumhttp://www.vrayforc4d.com/forummailto:[email protected]:[email protected]:[email protected]:[email protected]


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When you have activated Vray all renderings done in c4d will be made by the Vray rendercore. Thisworks in the perspective Camera Viewport and in the picture viewer, and in the interactive regionrender.

Activation within Cinema 4d 11

After installation you can activate VRAYforC4D as renderengine under:Render settings tab - Effects tab : Add effect Vraybridge.


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When you have activated Vray all renderings done in c4d will be made by the Vray rendercore. Thisworks in the perspective Camera Viewport and in the picture viewer, and in the interactive regionrender. In Cinema4D 11 you now can choose Vray from General Tab of Render Settings like any otherbuild-in render engine.

Notes You can make Vray the default engine when you start C4d by saving a file (that file must has Vray

already activated in render settings) called new.c4d in the main Cinema4d installation folder.


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Overview

Overview

Interface

Here You can see 2 VRAYforC4D scenes in Cinema4d as an screenshot:


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As you can see VRAYforC4D looks very much as the usual Advanced Render Workflow. The Materialand Render Settings are a bit different of course due to the other features and the more option.

You can render in the perspective Viewport and in the picture viewer juts as in normal c4d. All light,camera, material and tag settings can be adjusted in the C4D Attribute manager. The material can bealso adjusted in the C4D Material manager, as the Vray material has is very mighty i suggest using theadvanced Cinema Material editor to have best view of all Material adjustments.

All render settings are concentrated in the Vraybridge render setting tabs. You find them under

Render Setting - Effects - VrayBridge.

Render Settings

All main VRAYforC4D specific adjustments are concentrated here in the VRAYforC4D Render settings.You can adjust the Antialiasing, turn on Global Illumination (GI), choose and combine several GIMethods, adjust color mapping etc.

We tried the best to make the default settings already good for you. Basically it can be enough to justturn on GI on GI Tab, add light & materials and render your scene.

In reality you will want to make all fine tuning and adjustments. Also all professionals find here verydetails settings to adjust all to their needs. Users that have some knowledge of other VRAYforC4Dversion like the 3d max version will find the settings very familiar;-)

VRAYforC4D Material

The VRAYforC4D Material behaves just like a normal C4d Material. It shows in the normal C4d materialmanager.


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We recommend using the C4d material manager over the Attribute Manager as the VRAYforC4Dmaterial is very powerful and therefore has many many settings.

However the attribute manager of course is also possible to use, it just has a more dense appearanceand you might need to scroll more to see all setting options.

The VRAYforC4D BRDF material in the Cinema4d material editor:


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For rendering with the VRAYforC4D render engine You can use the VRAYforC4D BRDF Materials or usenative Cinema4D materials, also you can convert c4d materials to vray with one click converter, seepage about it)

Within the VRAYforC4D Material you can use almost all (98%) c4d shaders and even most normal 3rdparty shaders, like the great EnhanceC4D Shaders p.e., it also supports the powerfully c4d layershader, and the projector shader to apply different projections per shader.

The VRAYforC4D BRDF is a layered material system. Each layer has its own transparency mask.

For high glossy and laquere materials like car shaders, coatings etc. we have implemented 5 specular-glossy layers. They can blended and mixed together, each with different reflections, anisotropy andspecular.

For a detailed explanation of the materials setting go to Vray Material section.

Assigning Materials

To apply a VRAYforC4D material to Your objects and Scene just use the normal C4d workflow you areused to.


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You can drag and drop it p.e. to the object manager or directly to the objects in the Viewport, or usethe apply command....

A VRAYforC4D material can be applied to objects or to object groups. it uses the visibility buttons ofthe object manger.

Multiple VRAYforC4D Materials, each with different UVWs can be stacked like c4d Materials, and theycan also be applied to saved polygon selections on an object, just like the normal c4d materials. Alsoall tools for tags and material tags work as normal in c4d.

The UVW projection for each material tag is adjusted in the Attribute manager of Cinema4d in anidentical way as the c4d materials. in fact all UVW projections are handled natively by Cinema4d orBodypaint.

Please consult the Cinema4d documentation about the UVW Projections if you are new to Cinema4d.

VRAYforC4D Tags

VRAYforC4D uses the native Cinema 4d Lights and Cameras.

To have access to advanced VRAYforC4D features there are VRAYforC4D tags available for your choice:


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Tags VRAYforC4D Tag Name Description

VrayCompositing Similar to C4d Compositing.

VrayDisplacement For Micropolydisplacement, uses the UVW of the firstMaterial Tag.

VrayPhysicalCamera To use the wide settings of the VRAYforC4D physicalcamera.

VrayLight Transformed the normal c4d light into the powerfulphysical VRAYforC4D lights, to use the physical Sun andSky system, IES lights, photometric lights...

VrayMotionBlur To use VRAYforC4D Motion Blur

VrayCameraDome To use the Dome Light ability with VRAYforC4D.

VrmeshExporter Quick vray proxy mesh creating from c4d mesh.

Stack and Mix VRAYforC4D Materials

VRAYforC4D Materials can be stacked similar to C4d Materials. For now no selection tags supported onstacking, so if one want to stack same material more than once on same obects you must useinstances (copies) of this material to see all stacked materials. You can also use Vray Blend Material toachieve the similar effect.

Apply Materials, Check Mix Textures.


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Result.

The stacking order goes from left to right, so the most right material is the most on top. In thematerials you want to blend with the one below.

This is a blend of a glossy gray solid material in frontal mapping projection with a layered materialweight. it uses a B/W gradient mixed with a ornamental shader from Enhanced c4d shader set (Chrisfrom 3d attack.com). This material is blended to a Glass with transparency, sharp reflection, refractionand volume-transparency with spherical UVW mapping.

How it works? - you simple have to activate mix materials that use material weight, thats it!

This is also good for making decals (sticker on bottle, text on glass, et.). unlimited materials can bestacked or blended for almost unlimited possibilities.....


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Options

Options

Search Keywords: global options

GeneralThe Options allow you to control various aspects of the renderer globally.

Parameters Geometry

Displacement - enables (default) or disables VRAYforC4D's own displacement mapping.

Scene units - here you can setup scene units, it madded for quick setup, and to save parameters withfile.

Lighting

Lights - enables or disables lights globally.

Hidden lights - enables or disables the usage of hidden lights. When this is checked, lights are

rendered regardless of whether they are hidden or not. When this option is off, any lights that arehidden for any reason (either explicitly or by type) will not be included in the rendering.


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Shadows - enables or disables shadows globally.

Show GI only - when this option is on, direct lighting will not be included in the final rendering. Notethat lights will still be considered for GI calculations, however in the end only the indirect lighting willbe shown.

Photometric scale - this parameter allow to compensate exposure for non physical camera renders.

Indirect illumination

Don't render final image - when this option is on, VRAYforC4D will only calculate the relevant globalillumination maps (photon maps, light maps, irradiance maps). This is a useful option if you arecalculating maps for a fly-through animation.

Materials

Reflection/Refraction - enables or disables the calculation of reflections and refractions inVRAYforC4D maps and materials.

Max depth - enables the user to limit globally the reflection/refraction depth. When this is unchecked,the depth is controlled locally by the materials/maps. When this option is checked, all materials and

maps use the depth specified here.

Maps - enables or disables texture maps.

Filter maps - enables or disables texture map filtering. When enabled, the depth is controlled locallyby the settings of the texture maps. When disabled, no filtering is performed.

Max transparency levels - this controls to what depth transparent objects will be traced.

Transparency cutoff - this controls when tracing of transparent objects will be stopped. If theaccumulated transparency of a ray is below this threshold, no further tracing will be performed.

Glossy effects - this option allows the user to replace all glossy reflections in the scene with non-glossy ones; useful for test renderings.

Override material - this option allows the user to override the scene materials when rendering. Allobjects will be rendered with the chosen material, if one is selected, or with Default surface colormaterials if no material is specified.

Overriding material- this option allows to choose material that will be use for overriding scenematerials. Just drag and drop here vray material from Materials Manager.

Default surface color - color that replace all the scene materials when rendering.

Raytracing

Secondary rays bias - a small positive offset that will be applied to all secondary rays; this can beused if you have overlapping faces in the scene to avoid the black splotches that may appear.

Geometry back face cull - enables or disables (default) back face culling for camera and shadowrays. When this option is on, the surfaces of objects which are turned away from the camera (or thelight source, when tracing shadows) will appear fully transparent. This allows to look inside closedobjects when the camera is outside.

Cinema4D Volumetrics Effects

Volumetric Effects (experimental) - turning this option on will allow you to use Volumetric Effect

on Lights in VRAYforC4D. For use it you must also enable it in Cinema4D Light Common Options.

Miscellaneous options


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Optimized atmospheric evaluation - turning this option on will cause VRAYforC4D to first evaluatethe atmospheric effects, and shade the surface behind them only if the atmospherics are sufficientlytransparent.

Low thread priority - turning this on will cause VRAYforC4D to use threads of lower priority whenrendering.

Stamp Vray informations - the frame stamp is a convenient way to put some short text over the

rendered images. It can be useful in many ways - for example, in network rendering, to quicklydetermine which frames were rendered by which machine. The frame stamp is one line of text, whichappears at the bottom of the image.

Total Triangles - the number of unique intersectable primitives, such as a triangle, generated for thecurrent scene.

Label - here you enter the text you wish to appear in the images.


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Image Sampler (Antia-aliasing)

Antialiasing (Image Sampler)l

GeneralAntialiasing is one of the most important things for good digital produced images or animations.Vrayhas one of the best and most robust AA solutions available. In VRAY the antialiasing again is not just athing that gets applied after shading but the whole engine is connected to the image and DMCSamplers.

The same power that gives the GI engine its quality is also used for Images sampling. Thereforesometimes image sampling (Antialiasing) is used in vray also to support GI and glossy reflections. so

all setup is party connected, specially the adaptive DMC method.Why do we need AA in renderings? - in real word cameras or in the human eye the light goes throughmore or less perfect lenses. those lenses and also the air filter the light and compensate extremecontrast between near points. also analog methods are not bound to pixels and therefore do not haveto problem of pixel stepping when images do not have enough resolution or of very tiny and finestructures have to be rendered.

Vray can render ultra fine lines, by oversampling an image in an intelligent and still fast way. for areasthat don`t need much antialiasing vray can use under sampling - negative values - at the same time,depending on the method, this highly adaptive AA can give ultra crisp and still still soft results atreasonable render times. i believe one aspect of the high image quality in vray is not only the great GIengine but also the wonderful AA quality.

In vray you can use values like 100x AA with Adaptive DMC Sampling (with universal setting p.e.) andstill get ok render times. such extreme values wont be used all time, but they show the power behind.still high settings like 4x16x can be used at ultra high speeds for superb image quality. also i notedthat images with good AA can be scaled up much better than normal 3d images, so it might pay toinvest in learning the AA engine and use good quality settings.

In VRAYforC4D, an image sampler refers to an algorithm for sampling and filtering the image function,and producing the final array of pixels that constitute the rendered image.

VRAYforC4D implements several algorithms for sampling an image. You can choose between Fixedrate sampler, Adaptive DMCsampler and Adaptive subdivision sampler. Which is the fastestdepends very much on the scene and on the settings of GI, Materials etc.

Parameters

Image sampler


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Type - specifies the image sampler type:

Fixed- this sampler always takes the same number of samples per pixel;

Adaptive DMC- this sampler takes a variable number of samples per pixel depending on thedifference in the intensity of the pixels;

Adaptive subdivision - this sampler divides the image into an adaptive grid-like structure and refinesdepending on the difference in pixel intensity.

Antialiasing filter

Various filter can be applied, there are sharpening methods and blurring filters, depending on what youneed. for still images you might want to use sharpen filters,for animation make sure to use softenfilters!

Fixed rate sampler

This is the simplest image sampler,and it takes a fixed number of samples for each pixel.

Subdivision - determines number of samples per pixel. When this is set to 1, one sample at thecenter of each pixel is taken. If this is greater than 1, the samples are distributed within the pixel. Theactual number of pixels is the square of this parameter (e.g. 4 subdivisions produce 16 samples perpixel).

Note: that due to clamping of samples to the [black, white] range for the RGB color channel, sometimes this sampler can produce darker resultswhen used with blurry effects. The solution in this case is to increase the subdivisions for the blurry effect, or to use the Real RGB color channel.

.

Adaptive DMCsampler

This sampler makes a variable number of samples per pixel based on the difference in intensitybetween the pixel and its neighbors.

This is the preferred sampler for images with lots of small details and/or blurry effects (DOF, motionblur, glossy reflections etc). It also takes up less RAM than theAdaptive subdivision sampler.Note: that due to clamping of samples to the [black, white] range for the RGB color channel, sometimes this sampler can produce darker results

when used with blurry effects. The solution in this case is to increase the subdivisions for the blurry effect, or to use the Real RGB color channel..


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Min subdivision- determines the initial (minimum) number of samples taken for each pixel. You willrarely need to set this to more than 1, except if you have very thin lines that are not capturedcorrectly, or fast moving objects if you use motion blur. The actual number of pixels is the square ofthis number (e.g. 4 subdivisions produce 16 samples per pixel).

Max subdivision - determines the maximum number of samples for a pixel. The actual maximumnumber of sampler is the square of this number (e.g. 4 subdivisions produces a maximum of 16samples). Note that VRAYforC4D may take less than the maximum number of samples, if thedifference in intensity of the neighboring pixels is small enough.

Threshold - the threshold that will be used to determine if a pixel needs more samples.

Adaptive subdivision sampler

This is an advanced image samplercapable of under sampling (taking less than one sample per pixel). In the absence of blurry effects(direct GI, DOF, glossy reflection/refraction etc) this is the best preferred image sampler inVRAYforC4D. On average it takes fewer samples (and thus less time) to achieve the same imagequality as the other image samplers. However, with detailed textures and/or blurry effects, it can beslower and produce worse results than the other two methods.

Also note that this sampler takes up more RAM than the other two samplers - see the Notes below.

Min. rate - controls minimum number of samples per pixel. A value ofzero means one sample perpixel; -1 means one sample every two pixels; -2 means one sample every 4 pixels etc.

Max. rate - controls maximum number of samples per pixel; zero means one sample per pixel, 1means four samples, 2 means eight samples etc.

Jitter - displaces the samples slightly to produce better antialiasing of nearly horizontal or vertical.

Threshold - determines the sensitivity of the sampler to changes in pixel intensity. Lower values willproduce better results, while higher values will be faster, but may leave some areas of similar intensityunder sampled.

Object outline - this will cause the image sampler to always super sample object edges (regardless ofwhether they actually need to be super sampled). This option has no effect if DOF or motion blur is

enabled.

Material ID - uses the material id pass (change of material) to antialiasing the transition from one tothe next material on surface.

Normals - this will super sample areas with sharply varying normals. This option has no effect if DOFor motion blur is enabled.

Normals threshold - this will super sample areas with sharply varying normals. This option has noeffect if DOF or motion blur is enabled.

Z-Value - uses the z-depth pass (change of depth) to super sample the areas where a sudden depthchange occurs.

Z-Value threshold - adjusts the threshold of the above depth sampler.


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Notes Which sampler to use for a given scene? The answer is best found with experiments, but here are

some tips:

o For smooth scenes with only a few blurry effects and smooth textures, the Adaptive subdivisionsampler with its ability to under sample the image is unbeatable.

o For images with detailed textures or lots of geometry detail and only a few blurry effects, the

Adaptive DMCsampler performs best. Also in the case of animations involving detailed textures,the Adaptive subdivision sampler might produce jittering which the Adaptive DMCsampleravoids.

o For complex scenes with lots of blurry effects and/or detailed textures, the Fixed rate samplerperforms best and is very predictable with regards to the quality and render time.

A note on RAM usage: image samplers require substantial amount of RAM to store information abouteach bucket. Using large bucket sizes may take a lot of RAM. This is especially true for theAdaptivesubdivision sampler, which stores all individual sub-samples taken within a bucket. The AdaptiveDMCsampler and the Fixed rate sampler on the other hand only store the summed result of allsub-samples for a pixel and so usually require less RAM.


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DMC sampler

DMC samplerl

General Monte Carlo (MC) sampling is a method for evaluating "blurry" values (anitaliasing, depth of field,indirect illumination, area lights, glossy reflections/refractions, translucency, motion blur etc).VRAYforC4D uses a variant of Monte Carlo sampling called deterministic Monte Carlo (DMC). Thedifference between pure Monte Carlo sampling and deterministic Monte Carlo is that the first usespseudo-random numbers which are different for each and every evaluation (and so re-rendering asingle image will always produce slightly different results in the noise), while deterministic Monte Carlouses a pre-defined set of samples (possibly optimized to reduce the noise), which allows re-renderingan image to always produce the exact same result. By default, the deterministic Monte Carlo methodused by VRAYforC4D is a modficiation of Schlick sampling, introduced by Christophe Schlick in 1991

(see the References section below).

Note that there exists a sub-set of DMC sampling called quasi Monte Carlo (DMC) sampling, in which thesamples are obtained from sequences of numbers, called low-discrepancy sequences, which have specialnumeric properties. VRAYforC4D, however, does not use this technique.

Instead of having separate sampling methods for each of the blurry values, VRAYforC4D has a singleunified framework that determines how many and what exactly samples to be taken for a particularvalue, depending on the context in which that value is required. This framework is called the "DMCsampler".

The actual number of samples for any blurry value is determined based on three factors:

The subdivs value supplied by the user for a particular blurry effect. This is multiplied by the Globalsubdivs multiplier (see below).

The importance of the value (for example, dark glossy reflections can do with fewer samples thanbright ones, since the effect of the reflection on the final result is smaller; distant area lights requirefewer samples than closer ones etc). Basing the number of samples allocated for a value onimportance is called importance sampling.

The variance (think "noise") of the samples taken for a particular value - if the samples are not verydifferent from each other, then the value can do with fewer samples; if the samples are verydifferent, then a larger number of them will be necessary to get a good result. This basically worksby looking at the samples as they are computed one by one and deciding, after each new sample, ifmore samples are required. This technique is called early termination or adaptive sampling.

For more information on the relationship and effects of these parameters, please refer to the tutorialssection.

Parameters


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Adaptive amount - controls the extent to which the number of samples depends on the importance ofa blurry value. It also controls the minimum number of samples that will be taken. A value of 1.0means full adaptation; a value of 0.0 means no adaptation.

Noise threshold - controls VRAYforC4D's judgement of when a blurry value is "good enough" to beused. This directly translates to noise in the result. Smaller values mean less noise, more samples andhigher quality. A value of 0.0 means that no adaptation will be performed.

Global subdivs multiplier - this will multiply all subdivs values everywhere during rendering; you can

use this to quickly increase/decrease sampling quality everywhere. This affects everything, except forthe lightmap, photon map, caustics and aa subdivs. Everything else (dof, moblur, irradiance map,brute-force GI, area lights, area shadows, glossy reflections/refractions) is affected by this parameter.

Minimum samples - determines the minimum number of samples that must be made before the earlytermination algorithm is used. Higher values will slow things down but will make the early terminationalgorithm more reliable.

Time independent - when this option is On, the sampling pattern will be the same from frame toframe in an animation. Since this may be undesirable in some cases, you can turn this option Offtomake the samping pattern change with time. Note that re-rendering the same frame will produce thesame result in both cases.

ReferencesMore information on deterministic Monte Carlo sampling for computer graphics can be found from thesources listed below.

Schlick, C., 1991, An Adaptive Sampling Technique for Multidimensional Integraton by RayTracing, in Second Eurographics Workshop on Rendering (Spain), pp. 48-56Describes deterministic MC sampling for antialiasing, motion blur, depth of field, area light samplingand glossy reflections.

Masaki Aono and Ryutarou Ohbuchi, November 25, 1996, Quasi-Monte Carlo Rendering with

Adaptive Sampling, IBM Tokyo Research Laboratory Technical Report RT0167, pp.1-5;online version can be found hereDescribes an application of low discrepancy sequences to area light sampling and the globalillumination problem.

Fajardo, M., August 13, 2001, Monte Carlo Raytracing in Action, in State of the Art in MonteCarlo Ray Tracing for Realistic Image Synthesis, SIGGRAPH 2001 Course 21, pp. 151-162;online version can be found hereDescribes the ARNOLD renderer employing randomized quasi-Monte Carlo sampling using lowdiscrepancy sequences for pixel sampling, global illumination, area light sampling, motion blur, depthof field, etc.

Veach, E., December, 1997, Robust Monte Carlo Methods for Light Transport Simulation, Ph.D. dissertation for Stanford University, pp. 58-65online version can be found hereIncludes a description of low discrepancy sequences, quasi-Monte Carlo sampling and its applicationto solving the global illumination problem.

Szirmay-Kalos, L., 1998, Importance Driven Quasi-Monte Carlo Walk Solution of theRendering Equation, Winter School of Computer Graphics Conf., 1998online version can be found hereDescribes a two-pass method for solving the global illumination problem employing quasi-MonteCarlo sampling, as well as importance sampling using low discrepancy sequences.


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Indirect Illumination (GI)

Indirect illumination (GI)l

General

Global Illumination is getting more and more standard today, VRAYforC4D is built from ground up tonot only support it, but to be built directly for using the best GI algorithms around.

But what is GI, and what is it for?

In real world all what we see is possible due to light that travels from the light source to objects and

being reflected by these objects traveling to the next objects etc.

So the light is almost endless reflected from surface to surface. each object has a certain amount ofreflection (only absolute black bodies do not reflect, like a black whole in space). Through reflection wesee colors and light intensity, so basically what we see is all about light.

Classic render engines without GI do not consider the reflection of light, they only calculate the lightbetween the source and the first surface the light hits - this obviously very unrealistic and can only bepartly compensated by good and skilled artists.

Also the render engines today do not replace the need for an artist of course, but they give a muchmore powerful tool to play with light and surface properties, light in CG now behaves very close to how

we see it in nature, and it became much more predictable.

It is reflected between the objects in many bounces, so a room p.e. that has only one window isautomaticly filled with light, also in the parts where the sun beams do not directly hit a surface. Alsoluminance in objects or HDRI images add real light to the scene, the VRAYforC4D lights also have aphysical size in space and a physical correct intensity (in real world units) and falloff.

The VRAYforC4D material again is the counterpart to a good GI engine, VRAYforC4D has a highlyadvanced BRDF material model that has physical properties for all kind of reflections (mirror andglossy) and refraction (when light travels through a volume body), both: reflections and refractions canuse an IOR (index of refraction) like most real world materials, and anisotropy like materials withdirectional microstructure. The refraction takes volume, depth and surface structure into account and

therefore also can scatter light for things like sandblasted glass, wax, translucent leaves, skin, plasticsetc.

The combination of VRAYforC4D lights, VRAYforC4D brdf materials, and different high end GIalgorithms all together gives the unsurfaced image - and light quality famous in VRAYforC4D.

The human eye is capable of seeing the most fine nuances of color and light, and therefore it is justgood to use the best tools available, VRAYforC4D is one of them, delivering ultra highend quality,combined with great speed, and still being highly adaptive and versatile, to give the artist the choice tobreak the laws of physics where he wants to.

Examples for an image calculation with GI or without GI to see the main difference:


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No Global IIllumination (left image), the light (c4d sun) comes from the light source and hits thesurfaces., no further light transportation is calculated, good for certain cinematographic effects but farfrom reality.

With GI Button (right image) simply turned on you see, much more is happening, this is still just one

light source, but also the scattering of the light is calculated within the image, also the areas where thelight does not come to directly gets lit, the shadows are softer (area shadows), also the colors aredifferent as the blue sky reflects diffuse in to the shadow parts, where the sun is more dominant theslight yellow sunlight is visible, specially for architects, designers and others that want to have close toreally world light behavior GI can be a big advantage and help.

Approaches to indirect illumination

VRAYforC4D implements several approaches for computing indirect illumination with different trade-offs between quality and speed:

Brute force - this is the simplest approach; indirect illumination is computed independently for eachshaded surface point by tracing a number of rays in different directions on the hemisphere abovethat point.

Advantages:o this approach preserves all the detail (e.g. small and sharp shadows) in the indirect lighting; o it is free from defects like flickering in animations;o no additional memory is required;o indirect illumination in the case of motion-blurred moving objects is computed correctly.

Disadvantages:o the approach is very slow for complex images (e.g. interior lighting);

o it tends to produce noise in the images, which can be avoided only by shooting a larger number ofrays, thus slowing it even more.

Irradiance map - this approach is based on irradiance caching; the basic idea is to compute theindirect illumination only at some points in the scene, and interpolate for the rest of the points.

Advantages:o the irradiance map is very fast compared to direct computation, especially for scenes with large flat

areas;o the noise inherent to direct computation is greatly reduced;o the irradiance map can be saved an re-used to speed up calculations of different views for the

same scene and of fly-through animations;o

the irradiance map can also be used to accelerate direct diffuse lighting from area light sources. Disadvantages:


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o some details in indirect lighting can be lost or blurred due to the interpolation; o if low settings are used, flickering may occur when rendering animations;o the irradiance map requires additional memory;o indirect illumination with motion-blurred moving objects is not entirely correct and may lead to

noise (although in most cases this is not noticeable).

Photon map - this approach is based on tracing particles starting from the light sources andbouncing around the scene. This is useful for interior or semi-interior scenes with lots of lights orsmall windows. The photon map usually does not produce good enough results to be used directly;however it can be used as a rough approximation to the lighting in the scene to speed the calculationof GI through direct computation or irradiance map.

Advantages:o the photon map can produce a rough approximation of the lighting in the scene very quickly;o the photon map can be saved an re-used to speed up calculation of different views for the same

scene and of fly-through animations;o the photon map is view-independent.

Disadvantages:o the photon map usually is not suitable for direct visualization;o requires additional memory;o in VRAYforC4D's implementation, illumination involving motion-blurred moving objects is not

entirely correct (although this is not a problem in most cases).o the photon map needs actual lights in order to work; it cannot be used to produce indirect

illumination caused by environment lights (skylight).

Light cache - light caching is a technique for approximating the global illumination in a scene. It isvery similar to photon mapping, but without many of its limitations. The light map is built by tracingmany many eye paths from the camera. Each of the bounces in the path stores the illumination fromthe rest of the path into a 3d structure, very similar to the photon map. The light map is a universalGI solution that can be used for both interior or exterior scenes, either directly or as a secondarybounce approximation when used with the irradiance map or the brute force GI method.

Advantages:o the light cache is easy to set up. We only have the camera to trace rays from, as opposed to the

photon map, which must process each light in the scene and usually requires separate setup foreach light.

o the light-caching approach works efficiently with any lights - including skylight, self-illuminatedobjects, non-physical lights, photometric lights etc. In contrast, the photon map is limited in thelighting effects it can reproduce - for example, the photon map cannot reproduce the illuminationfrom skylight or from standard omni lights without inverse-square falloff.

o the light cache produces correct results in corners and around small objects. The photon map, on

the other hand, relies on tricky density estimation schemes, which often produce wrong results inthese cases, either darkening or brightening those areas.

o in many cases the light cache can be visualized directly for very fast and smooth previews of thelighting in the scene.

Disadvantages:o like the irradiance map, the light cache is view-dependent and is generated for a particular position

of the camera. However, it generates an approximation for indirectly visible parts of the scene aswell - for example, one light cache can approximate completely the GI in a closed room;

o currently the light cache works only with VRAYforC4D materials;o like the photon map, the light cache is not adaptive. The irradiance is computed at a fixed

resolution, which is determined by the user;o the light cache does not work very well with bump maps; use the irradiance map or brute force GI

if you want to achieve better results with bump maps.

o lighting involving motion-blurred moving objects is not entirely correct, but is very smooth sincethe light cache blurs GI in time as well (as opposed to the irradiance map, where each sample iscomputed at a particular instant of time).


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Which method to use? That depends on the task at hand.

Primary and secondary bounces

The indirect illumination controls in VRAYforC4D are divided into two large sections: controlsconcerning primary diffuse bounces and controls concerning secondary diffuse bounces. A primary bounceoccurs when a shaded point is directly visible by the camera, or through specular reflective or

refractive surfaces. A secondary bounce occurs when a shaded point is used in GI calculations.

It often is very efficient to mix to different engines: one for the primary and one for the secondarybounces, to have the advantages from both. One engine can be faster for one thing and the other foranother aspect. If you select one or two GI methods you will see that the corresponding GI setting tabswill be visible, the non chosen GI methods will be hidden for more visible clearness.

VRAYforC4D can combine them in an intelligent way to give you high speed with very high quality atthe same time, also for certain animation types it makes sense to mix fast smooth solutions withphysical accurate ones p.e. Combining 2 engines for primary and secondary GI is actually the standardway to work in VRAYforC4D.

Parameters

GI on - turn indirect illuminationon and off.

Save Gi Settings - you can save yours GI settings.

Load Gi Settings - you can load previously saved yours GI settings.

Presets - this dropdown list allows you to choose from several presets for some of the irradiance map

parameters. You can use these to quickly set the color, normal and distance thresholds, as well as themin/max rates. The following presets are available: Custom - defines by you. Very low Quality- this preset is only useful for preview purposes to show the general lighting in the

scene. LowQuality- a low-quality preset for preview purposes. Medium Quality - a medium quality preset; works fine in many situations in scenes which have

don't small details. Medium animation Quality- a medium quality preset targeted at reducing flickering in animations

- the Distance threshold of Irradiance map is higher. High Quality- a high-quality preset that works in most situations, even for scenes with small details

as well as for most animations. High animation Quality - a high-quality preset that can be used if the High preset produces

flickering in animations - the Distance threshold of Irradiance map is higher.


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Very high Quality - a very high quality preset; can be used for scenes with extremely small andintricate details.

Unbiased- outstanding quality and outstanding time.

Note that the presets are targeted for a typical 640x480 image. Larger images usually can do withlower Min/Max rates than those specified in the presets.

GI Caustics

GI caustics represent light that has gone through one diffuse, and one or several specular reflections(or refractions). GI caustics can can be generated by skylight, or self-illuminated objects, for example.However, caustics caused by direct lights cannot be simulated in this way. You must use the separateCaustics section to control direct light caustics. Note that GI caustics are usually hard to sample andmay introduce noise in the GI solution.

Reflective - this allows indirect light to be reflected from specular objects (mirrors etc). Note that thisis not the same as Caustics, which represent direct light going through specular surfaces. This is offbydefault, because reflective GI caustics usually contribute little to the final illumination, while often theyproduce undesired subtle noise.

Refractive - this allows indirect lighting to pass through transparent objects (glass etc). Note that thisis not the same as Caustics, which represent direct light going through transparent objects. You needrefractive GI caustics to get skylight through windows, for example.

Post-Processing

These controls allow additional modification of the indirect illumination, before it is added to the finalrendering. The default values ensure a physically accurate result; however the user may want tomodify the way GI looks for artistic purposes.

Saturation - controls the saturation of the GI; a value of 0.0 means that all color will be removedfrom the GI solution and will be in shades of gray only. The default value of1.0 means the GI solution

remains unmodified. Values above 1.0 boost the colors in the GI solution.

Contrast - this parameter works together with Contrast base to boost the contrast of the GI solution.When Contrast is 0.0, the GI solution becomes completely uniform with the value defined by Contrastbase. A value of 1.0 means the solution remains unmodified. Values higher that 1.0 boost thecontrast.

Contrast base - this parameter determines the base for the contrast boost. It defines the GI valuesthat remain unchanged during the contrast calculations.

Save Maps per Frame - when this option is on, VRAYforC4D will save all GI maps (irradiance map,photon map, caustic, light maps) if in options they set to Auto-Save.

Primary bounces

Multiplier - this value determines how much primary diffuse bounces contribute to the final imageillumination. Note that the default value of 1.0 produces a physically accurate image. Other values arepossible, but not physically plausible.

GI engine - the list box specifies the method to be used for primary diffuse bounces.

Irradiance map - selecting this will cause VRAYforC4D to use an irradiance map for primary diffusebounces. See the Irradiance map section for more information.

Photon map - selecting this option will cause VRAYforC4D to use a photon map for primary diffusebounces. This mode is useful when setting up the parameters of the global photon map. Usually it does


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not produce good enough results for final renderings when used as a primary GI engine. See thePhoton map section for more information.

Brute force - selecting this method will cause VRAYforC4D to use direct computation for primarydiffuse bounces. See the brute force section for more information.

Light cache - this chooses the light cache as the primary GI engine. See the Light cache section formore information.

Secondary bounces

Multiplier - this determines the effect of secondary diffuse bounces on the scene illumination. Valuesclose to 1.0 may tend to wash out the scene, while values around 0.0 may produce a dark image. Notethat the default value of 1.0 produces physically accurate results. While other values are possible, theyare not physically plausible.

GI engine - this parameter determines how VRAYforC4D will calculate secondary diffuse bounces.

None - no secondary bounces will be computed. Use this option to produce skylight iimages withoutindirect color bleeding.

Photon map - selecting this option will cause VRAYforC4D to use a photon map for primary diffusebounces. This mode is useful when setting up the parameters of the global photon map. Usually it doesnot produce good enough results for final renderings when used as a primary GI engine. See thePhoton map section for more information.

Brute force - selecting this method will cause VRAYforC4D to use direct computation for primarydiffuse bounces. See the Brute force section for more information.

Light cache - this chooses the light cache as the primary GI engine. See the Light cache section formore information.

Notes You will get physically accurate lighting if you set both the primary and secondary GI multipliers to

their default value of 1.0. While other values are possible, they will not produce a physically accurateresult.


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Brute force GI

Brute force GIl

Search Keywords: brute force, direct calculation, GI

GeneralThis section is available only if you have chosen Brute force GIas either the primary or the secondaryGI engine.

The brute force method for computing global illumination recomputes the GI values for every singleshaded point separately and independently from other points. While very slow, this method is veryaccurate, especially if you have many small details in the scene.

To speed up brute force GI, you can use a faster method (the photon map or the light map) forapproximating secondary GI bounces, while using the brute force method for the primary bounces oryou can use the OMC engine as the secondary bounce engine to combine and refine a Irradiance MapGI solution.

Parameters

Subdivision - this determines thenumber of samples used to approximate GI. Note that this is not the exact number of rays that

VRAYforC4D will trace. The number of rays is proportional to the square of this number, but alsodepends on the settings in the DMC sampler rollout.

Ray depth - this parameter is available only if Brute Force GI is selected as a secondary GI engine. Itcontrols the number of light bounces that will be computed.


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Irradiance map

Irradiance mapl

GeneralThis section allows the user to control and fine-tune various aspects of the irradiance map. This sectionis enabled only when the irradiance map is chosen as the GI method for primary diffuse bounces.

Some background for understanding how the irradiance map works is necessary in order to grasp themeaning of these parameters.

Irradiance is a function defined for any point in the 3D space and represents the light arriving at this

point from all possible directions. In general, irradiance is different in every point and in everydirection. However, there are two useful restrictions that can be made. The first is the surface irradiance- which is the irradiance arriving at points which lie on the surface of objects in the scene. This is anatural restriction since we are usually interested in the illumination of objects in the scene, andobjects are usually defined through their surface. The second restriction is that of diffuse surfaceirradiance - which is the total amount of light arriving at a given surface point, disregarding thedirection from which it comes.

In more simple terms, one can think of the diffuse surface irradiance as being the visible color of asurface, if we assume that its material is purely white and diffuse.

In VRAYforC4D, the term irradiance map refers to a method of efficiently computing the diffuse surface

irradiance for objects in the scene. Since not all parts of the scene have the same detail in indirectillumination, it makes sense to compute GI more accurately in the important parts (e.g. where objectsare close to each other, or in places with sharp GI shadows), and less accurately in uninteresting parts(e.g. large uniformly lit areas). The irradiance map is therefore built adaptively. This is done byrendering the image several times (each rendering is called a pass) with the rendering resolution beingdoubled with each pass. The idea is to start with a low resolution (say a quarter of the resolution of thefinal image) and work up to the final image resolution.

The irradiance map is in fact a collection of points in 3d space (a point cloud) along with the computedindirect illumination at those points. When an object is hit during a GI pass, VRAYforC4D looks into theirradiance map to see if there are any points similar in position and orientation to the current one.From those already computed points, VRAYforC4D can extract various information (i.e. if there are any

objects close by, how fast the indirect illumination is varying etc). Based on that information,VRAYforC4D decides if the indirect illumination for the current point can be adequately interpolatedfrom the points already in the irradiance map, or not. If not, the indirect illumination for the currentpoint is computed, and that point is stored in the irradiance map. During the actual rendering,VRAYforC4D uses a sophisticated interpolation method to derive an approximation of the irradiance forall surfaces in the scene


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Parameters

Basic parameters

Min rate - this value determines the resolution for the first GI pass. A value of 0 means the resolutionwill be the same as the resolution of the final rendered image, which will make the irradiance mapsimilar to the direct computation method. A value of-1 means the resolution will be half that of thefinal image and so on. You would usually want to keep this negative, so that GI is quickly computed for

large and flat regions in the image. This parameter is similar to (although not the same as) the Minrate parameter of theAdaptive subdivision image sampler.

Max rate - this value determines the resolution of the last GI pass. This is similar to (although not thesame as) the Max rate parameter of theAdaptive subdivision image sampler.

Hemispheric Subdivision - this controls the quality of individual GI samples. Smaller values makethings faster, but may produce blotchy result. Higher values produce smoother images. This is similarto the Subdivision parameter for direct computation. Note that this is not the actual number of raysthat will be traced. The actual number of rays is proportional to the square of this value and alsodepends on the settings in the DMC sampler.

Interpolation samples - this is the number of GI samples that will be used to interpolate the indirectillumination at a given point. Larger values tend to blur the detail in GI although the result will be


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smoother. Smaller values produce results with more detail, but may produce blotchiness if lowHemispheric Subdivision are used.

Interpolation frames - this determines the number of frames that will be used to interpolate GIwhen the Mode is set to Animation (rendering). In this mode, VRAYforC4D interpolates theirradiance from the maps of several adjacent frames to help smooth out any flickering. Note that theactual number of frames used is 2*(interp. frames)+1 - e.g. the default value of2 means that intotal 5irradiance maps will be interpolated. Higher values slow down the rendering and may produce"lagging" effect. Lower values render faster but may increase flickering.

Intensity threshold - this parameter controls how sensitive the irradiance map algorithm is tochanges in indirect lighting. Larger values mean less sensitivity; smaller values make the irradiancemap more sensitive to light changes (thus producing higher quality images).

Normal threshold - this parameter controls how sensitive the irradiance map is to changes in surfacen

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