[Bf-committers] Update random seed between sub-frames (old subject:QMC sampling)

[Magnus Löfgren]

Hi,

Quick follow-up on this subject:
Is it possible to update the random seed on QMC adaptive or QMC constant
between each motion sample in Full Scene Motion Blur?
For Shadows, Reflections and AO.

This could possibly decrease rendertimes by an order of magnitude for a
raytrace heavy scene.

Short example if you render the scene with a minimum amount of shadow,
reflection and AO samples:

Current implementation:
Render first sub-frame, render second sub-frame, render third subframe.
Noise pattern identical between subframes and result shows heavy noise.

Proposed implementation:
Render first sub-frame, update random seed, render second sub-frame, update
random seed, render third subframe. Noise patterns get's accumulated, end
result identical to using 3 more shadow/reflection/AO samples.


I've been trying to make sense of the source code and try to change this
myself but my brain just isn't wired that way, it's all hieroglyphs to me :)

Thanks