This changes the bent normal effect to be a bit more subtle.
I also tuned down the bent normal blending factor so mesh faceted look may
appear more in occluded regions. this is to increase the fidelity of the
indirect lighting. This blending might be a parameter in the future.
Based the calculation on "Bent Normals and Cones in Screen-space"
by O. Klehm, T. Ritschel, E. Eisemann, H.-P. Seidel
This is an optimization / cleanup commit.
The use of a global ubo remove lots of uniform lookups and only transfert data when needed.
Lots of renaming for more consistent codestyle.
This means we have less overall noise for rendered image.
SSR, AO, and Refraction are affected by this change.
SSR still exhibit artifacts because the reconstruction pattern needs to change every frame (TODO).
This includes big improvement:
- The horizon search is decoupled from the BSDF evaluation. This means using multiple BSDF nodes have a much lower impact when enbaling AO.
- The horizon search is optimized by splitting the search into 4 corners searching similar directions to help which GPU cache coherence.
- The AO options are now uniforms and do not trigger shader recompilation (aka. freeze UI).
- Include a quality slider similar to the SSR one.
- Add a switch for disabling bounce light approximation.
- Fix problem with Bent Normals when occlusion get very dark.
- Add a denoise option to that takes the neighbors pixel values via glsl derivatives. This reduces noise but exhibit 2x2 blocky artifacts.
The downside : Separating the horizon search uses more memory (~3MB for each samples on HD viewport). We could lower the bit depth to 4bit per horizon but it produce noticeable banding (might be fixed with some dithering).
I couldn't reproduce either, but calling min() with different argument
data types and indexing vectors with an index not known at compile time
seem likely to cause problems.
Ref T52404, T52404.
This fix a bug when occluder are on the edge of the screen and occludes more than they should.
Grouped the texture fetches together and clamp the ray at the border of the screen.
Also add a few util functions.
Implement GTAO (Ground Truth Ambient Occlusion) which is a special case of Horizon Based Ambient Occlusion that is more physically accurate.
Also add a bent normal option to sample indirect irradiance (diffuse lighting) with the least occluded direction.
