Computer Graphics from your pockets to your CAVE

Achille Peternier, Ph. D. Student

VRLab, EPFL, Switzerland

Plan

1. Introduction

2. Goals

3. Our solution1. System architecture

2. Examples

3. Evaluation/Benchmark

4. Conclusion

1. Introduction (1)

Unique framework for 3D graphics

handheld devices, PDAs, mobile

phones

UMPCs, low profile PCs

Desktop PCs, modern graphics

accelerators

CAVE systems, multi-display environments

1. Introduction (2)

handheld devices UMPCs

• low resources and computational power• lack of 3D dedicated HW or poor performances

• Intel GMA 900/950 family• OpenGL | ES• OpenGL < 1.5

• closed systems

1. Introduction (3)

Desktop PCs CAVE systems

• Very heterogeneous HW • NVidia, ATI, Intel, …• OpenGL 1.1 -> OpenGL 3.0

• Network architecture (and again heterogeneous HW)• Stereographic rendering cutting performances

2. Goals (1)ConceptResult

Software

Device

Project

2. Goals (2)

• Reducing complexity and development times for cross-device graphics applications

• Making development and porting as simple as possible

• Keeping the same functionalities and performances across different platforms, or let the software automatically adapt it for us (models, GUIs, textures, shaders, etc.)

3. Our solution

• Mental Vision: a cross-device 2D/3D graphics engine:– Very simple interface (good learning curve)

• Maximizing effects reducing lines of code• Minimizing differences among different platforms

– Compact in sizes and fast in speed (important for low profile/mobile devices)

– Robust (consistent results across different devices)

3. Our solution: architecture (1)3D models3D models

TexturesTextures

AnimationsAnimations

EffectsEffects

User application

Mental Vision 2D/3D engine

GUIGUI

Content adaptationContent adaptation

Dynamic scene graphDynamic scene graph

Handheld renderingHandheld rendering

PC renderingPC rendering

CAVE renderingCAVE rendering

Engine APIEngine API

3. Our solution: architecture (2)

Mental Vision 2D/3D engine

Handheld renderingHandheld rendering

Fixed mathFixed math

OpenGL|ES (HW/SW)OpenGL|ES (HW/SW)

Mental Vision 2D/3D engine

PC renderingPC rendering

OpenGL (1.1 -> 2.1)OpenGL (1.1 -> 2.1)

Fixed pipelineFixed pipeline

Fixed/Shader pipelineFixed/Shader pipeline

F/XF/X

3. Our solution: architecture (3)

Mental Vision 2D/3D engine

CAVE renderingCAVE rendering

Network architectureNetwork architecture

3. Our solution: architecture (4)

3. Our solution: PC example#include <mvisio.h>

int main(int argc, char *argv[]){ MVISIO::init(NULL); MVNODE *bunny = MVISIO::load("bunny.mve"); MVISIO::clear(true, true, true); MVISIO::begin3D(NULL); bunny->pass(); MVISIO::end3D(); MVISIO::swap(); MVISIO::free(); return 0;}

Initialize MVisio (NULL means auto-setup)

Load a scene from native format

Clear buffers, start a 3D rendering, tell MVisio to render the bunny entity, execute the rendering, swap back to front buffer

Free resources

3. Our solution: PDA example#define MV_PDA#include <mvisio.h>

int main(int argc, char *argv[]){ MVISIO::init(NULL); MVNODE *bunny = MVISIO::load("bunny.mve"); MVISIO::clear(true, true, true); MVISIO::begin3D(NULL); bunny->pass(); MVISIO::end3D(); MVISIO::swap(); _sleep(5000); MVISIO::free(); return 0;}

Just define that before including MVisio, that’s all!

3. Our solution: CAVE example#define MV_CAVE#include <mvisio.h>

int main(int argc, char *argv[]){ MVCLIENT *front = new MVCLIENT(); front->set IP(“192.168.0.1”); front->setID(MV_FRONT);

MVCLIENT *right = new MVCLIENT(); right->set IP(“192.168.0.2”); right->setID(MV_RIGHT); // …

MVISIO::init(NULL); MVNODE *bunny = MVISIO::load("bunny.mve");

Define that first

Add CAVE sides here

3. Our solution: CAVE example

MVCLIENT::putUser(1.2, 1.6, 1.2);

MVISIO::clear(true, true, true); MVISIO::begin3D(NULL); bunny->pass(); MVISIO::end3D(); MVISIO::swap(); _sleep(5000); MVISIO::free(); return 0;}

Specify user’s head position in CAVE relative coordinates

3. Our solution: technical detailsOther aspects/details (like engine expansion, MR/VR related aspects, corollary

tools, plugins, CAVE calibration, etc.):

• A. Peternier, F. Vexo, D. Thalmann, The Mental Vision framework: a platform for teaching, practicing and researching with Computer Graphics and Virtual Reality, LNCS Transactions on Edutainment, 2008

• A. Peternier, F. Vexo, D. Thalmann, Wearable Mixed Reality System In Less Than 1 Pound, In Proc. of the 12th Eurographics Symposium on Virtual Environments, Lisbon, Portugal, May 2006

• A. Peternier, S. Cardin, F. Vexo, D. Thalmann, Practical Design and Implementation of a CAVE System, 2nd International Conference on Computer Graphics, Theory and Applications, GRAPP 2007, Barcelona, 2007

3. Our solution: benchmark (1)• Simple cross device application tracking fps and using three different models:

• classic static Standford bunny• a building model (using many separated entities and transparencies)• a 86 bones skinned, animated, textured virtual human

• Basic GUI (some text, a couple of buttons)• We want to evaluate speed issues and visual consistency among different platforms.

3. Our solution: benchmark (2)PDA software rendering(OGL|ES Rasteroid 1.0 CL)

Screen size: 320x240

Bunny: ~5.9 fps Building: ~9.3 fpsV. human: ~6.7 fps

3. Our solution: benchmark (3)PDA hardware rendering(OGL|ES MBX-lite 1.0 CL)

Screen size: 640x480

Bunny: ~23 fps Building: ~34 fpsV. human: ~14 fps

3. Our solution: benchmark (4)PC hardware rendering(Nvidia GForce 8800 GT, Core2 Quad @ 2.4 GHz)

Screen size: 640x480

Bunny: >1400 fps Building: >1000 fpsV. human: ~560 fps

3. Our solution: benchmark (5)

2D GUI2D GUI

3D rendering3D rendering4 side CAVE rendering(1 server PC, 4 clients)Screen size: 1024x768 (each)Nvidia 9800 GTX

Bunny: >1400 fps Building: >1000 fpsV. human: ~560 fps

4. Conclusion (1)

• 3D everywhere is possible today by using the correct approach and system architecture.

• Cross-device applications open new scenarios/applications, mainly when porting across different systems can be achieved “for free”.

4. Conclusion (2)

• Versatility doesn’t need to be sacrificed in the process.

Thank you

…questions?