33 milliseconds in hell - derschmale.com · Recursively divide an expensive task in smaller sized...

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33 milliseconds in hellDamn you 30 fps!

www.derschmale.comwww.away3d.com@DerSchmale

David Lenaerts

Introduction33 milliseconds in hell

Brief summaryReal time effects: 30 – 60 fps

Limitations Flash Player (oldskool, yo)

Tips & tricks

Mindset

Examples + demos

Commodore 64 (BASIC) PC

Doom, Quake, ...id Software nut: Carmack FTW (@ID_AA_Carmack)90's PC demo scene

Real-time effects2D & 3D graphical programming

Turbo Pascal, C/C++ (DOS: 0xa000)

Flash MXjust like the old days

IntroductionOff the beaten path

Down memory lane

2D + 3D graphical effects

Visual simulations

ActionScript / Pixel Bender / C++ (Alchemy)

Creating visual effects, not art

Introduction33 milliseconds in hell

The present

The boring bits33 milliseconds in hell

IntelliJ, FDT, Flash Builder, ...

Productivity: code less, think more

Refactoring support + code generation

Overview on code

Profiler (Flash Builder, FDT)

Toolset33 milliseconds in hell

Version: 9 vs 10 vs 10.1

Convince your clients!

Debug vs Release Player

Flash player

Other toolsPixel Bender toolkit / Joa Ebert's PBDT

http://blog.joa-ebert.com/pbdt/

Alchemy

Joa Ebert's Apparat suitehttp://apparat.googlecode.com

Know your tools!

Recursively divide an expensive task in smaller sized subtasks

Divide → Solve → Combine → Conquer

Example: merge sort

Conceptual33 milliseconds in hell

Divide & Conquer vs Brute Force

D&C: Merge sort

Get lazy, escape earlyAvoid expensive tasks: is the task even necessary?

Check necessity with a cheaper test(s)

Example:

Which of 100 objects am I hitting?

→ Am I even CLOSE to an object?

Get lazy, escape earlyCan work even better with Divide and Conquer approach

The fun bits33 milliseconds in hell

Faking it33 milliseconds in hell

You faked it?!Of course: All real time effects are fake in a sense

Creating something that works with strict preconditions

Baked lighting (Away3D + Prefab3D)

Casting shadows

Surmounting scale33 milliseconds in hell

Render loop

Render loopTransform and projection cost increases per vertex

Sort and draw cost increases with triangle count

In a huge scene, we're screwed, right?

Binary Space Partitioning (BSP)No sorting

Divide & Conquer

Split scene recursively until we have parts that need no sorting

Simply draw parts in correct order

Precomputed

Also speeds up collision detection

Potentially Visible Set (PVS)Early escape: reduce triangle and vertex count

Which parts in a BSP tree could never be seen from other parts?(per part: simply keep lists of potentially visible parts)

Find the part containing the camera

Only render the parts in the visibility list

BSP/PVS in Away3DObsolete on desktop

Great for Flash!

Generated by Prefab3D

http://www.closier.nl/prefab/

http://www.influxis.com/battlecell/

Pixel bender33 milliseconds in hell

Pixel Bender basics0 or more images → 1 output image

Function per output pixel (so no random access)

Multicore

Can apply it as filter to Flash 3D

Away3D shaders

Apply Pixel Bender on a texture

Position and direction data needed,encoded in bitmaps (rgb ~ xyz)

Problem: only static meshes

Away3D shaders

Dynamic meshes

Procedurally generating position map

Calculate normal map from that

Update mesh according to position mapl

Chaining

Chain together several pixel bender effects

Output previous effect is next input

Field-based physic simulations

Isosurfaces

Surface of equal values

Cfr weather report (2D)

Marching cubes

Don't use Pixel Bender to output image

Number crunching (isovalues, surface normals, ...)

Procedurally create triangles

Order of triangle creation → no sorting or transform needed

→ much higher polycount

Also check: Frank Reitberger – http://prinzipiell.com/

Marching cubes: render loop

Demo: Metaballs / Julia Set

Alchemy33 milliseconds in hell

Adobe Alchemy

Compile C/C++ code to ABC

Access fast memory

GCC/G++ does a lot of code optimizing

The last bits33 milliseconds in hell

What, when, how33 milliseconds in hell

What to optimizePretty code vs fast code

Inlining methods1-lining statements

Algorithms/Data structuresThe bigger pictureDivide & ConquerTree structures (BSP, Quadtree Raytracer)Can have most impact on performance

What, when, how33 milliseconds in hell

When to optimizePretty code vs fast code

Wait as long as you canWhen it works

Algorithms/Data structuresUp front“This is going nowhere”Changing tools can cause change of algorithms

The devil in the 9th circle33 milliseconds in hell

WorkflowDesigners vs Developers

Sit together from the get-go

A linear hand-over approach does not work

Give and take

Mediator: director

Closing off33 milliseconds in hell

Evoflash – Spiral OutSimo Santavirta – http://www.simppa.fi

Evoflash – http://evo.bombsquad.org

Real-time “demo-scene” demo in Flash

#1 at Assembly 2010 \m/

Thank you!33 milliseconds in hell

Questions?

David Lenaertswww.derschmale.com

twitter.com/DerSchmale

33 milliseconds in hell - derschmale.com · Recursively divide an expensive task in smaller sized...

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