1. Robust Diffuse Final Gathering on the GPU
Tamás Umenhoffer, László Szirmay-Kalos
Department of Control Engineering and Information Technology, Budapest University of Technology, Hungary

2. Indirect Illumination

3. Angle between illumination direction and surface normals
Rendering Equation
Angle between illumination direction and surface normals
at x and y
Incoming radiance to x
Visibility indicator
between
x and y

4. Ray Casting
illuminating
points
eye
pixel
sample
point

5. Environment Mapping
radiance,
distance

6. Virtual area light sources
Virtual lights
group lights
Area lights

7. Cubemap downsample 256 x 256 x 6 4 x 4 x 6
Average radiance and distance values
Downsample
4 x 4 x 6
one pixel – one area light

8. Point to point form factor

9. Polygon to point form factor

10. Polygon to point form factor
tangent plane + + -

11. Results
Point to
point
Polygon to
point

12. Classic
Point to point
Polygon to point
Mental Ray
600 FPS
60 FPS
11 FPS
30 sec

13. Results

14. Results

16. Conclusion Robust diffuse final gathering Cube map GPU
Interactive / real-time

17. Thank you for your attention!