Introduction to Global Illumination by Aryo

@agatestudio

Introduction to Global Illumination

Aryo

Knight

Agate Studio

Introduction to Global Illumination

Agustinus Arya Adhinugraha

Direct Lighting Only 800x600 : 1.42045ms – 704fps

-Draw scene depth from light point of view (for shadow purpose).

-Draw deferred into GBuffer(albedo, normal, depth).

-Draw direct shading & shadow.

Reflective Shadow Map (RSM) 128x128 Color (left), Screen Position (center), Light Direction (right) - Draw scene from light point of view, and output color, screen position, and light direction.

Virtual Point Lights (VPL) Position

800x600 36 VPL: 21.2766ms – 47fps

- Select VPL from RSM (CPU)

Indirect Lighting Only

- Draw scene and treat each of VPL as common light.

Final (Direct + Indirect Lighting) 800x600 36 Draw VPL : 21.2766ms – 47fps 1 Draw 36 VPL : 15.3846ms – 65fps - Optimized VPL to array of VPL and iterate in fragment shader.

Light Propagation Volume (LPV) 800x600 8x8x8 LPV : >1000ms - <1fps

-CryEngine3 method

-Using spherical harmonics coefficients

- Currently CPU Only (time constraint)

Radiance Map

800x600 8x8 RM : 2.087ms – 481fps

-Based on LPV, but using 2D texture instead of 3D one.

-Need further research

Reference Image

800x600 Blender cycles : 18910ms

References

• http://www.vis.uni-stuttgart.de/~dachsbcn/download/gi/screen_space.pdf

• http://www.vis.uni-stuttgart.de/~dachsbcn/download/gi/vpl.pdf

• http://www.crytek.com/download/20100301_lpv.pdf

• http://www.research.scea.com/gdc2003/spherical-harmonic-lighting.pdf