This was the cause of some issue with normal mapping. This way is cleaner
since it does not modify the state of the drawcalls and other ad-hoc
solutions to fix the problems down the road. Unfortunately, it does require
to fix every sampling coordinate for this texture.
Fix T62215: flipped normals in reflection plane
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.
There was noise correlation between the rotation random number and the radius random number used in the contact shadow algo.
Hacking a new distribution from the old distribution (may not be ideal because it's discrepency may be high)
Also distribute samples evenly on the shadow disc. (add sqrt)
Fix the "bias floating shadows", was cause by the discarding of backfacing geom which makes no sense in this case.
The problem was that orthographic views can have hit position that are negative. Thus we cannot encode the hit in the sign of the Z component.
The workaround is to store the hit position in screenspace. But since we are using floating point render target, we are loosing quite a bit of precision.
TODO: use RGBA16 instead of RGBA16F. But that means encoding the pdf value somehow.
We track the previous ray position offseted by the thickness. If the sampled depth is between this value and the current ray position then we have a hit.
This fixes rays that are almost colinear with the view vector. Thickness is now only important for rays that are comming back to the camera.
As a consequence, this simplify a lot of things.
Also include some refactor.
Since we are working with non power of 2 textures, the mipmap level UV does not line up perfectly.
This resulted in skewed filtering and bad sampling of the min/max depth buffer.
It now uses a quality slider instead of stride.
Lower quality takes larger strides between samples and use lower mips when tracing rough rays.
Now raytracing is done entierly in homogeneous coordinate space. This run much faster.
Should be fairly optimized. We are still Bandwidth bound.
Add a line-line intersection refine.
Add a ray jitter between the multiple ray per pixel to fill some undersampling in mirror reflections.
The tracing now stops if it goes behind an object. This needs some work to allow it to continue even if behind objects.
This add the possibility to use planar probe informations to create SSR.
This has 2 advantages:
- Tracing is less expensive since the hit is found much quicker.
- We have much less artifact due to missing information.
There is still area for improvement.
- Encode normals for other opaque bsdf so they are not rejected by the normal facing test.
- Early out non reflective surfaces.
- Add small offset to raytrace to avoid self intersection.
- Fix fallback probes not appearing.
