Fix regression with roughness not masking reflections when not using
Screen Space raytracing.
The trick was to only evaluate one planar per pixel, the one with
the most influence. This should not be too limiting since this is what
we do for SSR.
Also change evaluation order do not apply occlusion on planars probes.
This refactor was needed for some reasons:
- closure_lit_lib.glsl was unreadable and could not be easily extended to use new features.
- It was generating ~5K LOC for any shader. Slowing down compilation.
- Some calculations were incorrect and BSDF/Closure code had lots of workaround/hacks.
What this refactor does:
- Add some macros to define the light object loops / eval.
- Clear separation between each closures which now have separate files. Each closure implements the eval functions.
- Make principled BSDF a bit more correct in some cases (specular coloring, mix between glass and opaque).
- The BSDF term are applied outside of the eval function and on the whole lighting (was separated for lights before).
- Make light iteration last to avoid carrying more data than needed.
- Makes sure that all inputs are within correct ranges before evaluating the closures (use `safe_normalize` on normals).
- Making each BSDF isolated means that we might carry duplicated data (normals for instance) but this should be optimized by compilers.
- Makes Translucent BSDF its own closure type to avoid having to disable raytraced shadows using hacks.
- Separate transmission roughness is now working on Principled BSDF.
- Makes principled shader variations using constants. Removing a lot of duplicated code. This needed `const` keyword detection in `gpu_material_library.c`.
- SSR/SSS masking and data loading is a bit more consistent and defined outside of closure eval. The loading functions will act as accumulator if the lighting is not to be separated.
- SSR pass now do a full deferred lighting evaluation, including lights, in order to avoid interference with the closure eval code. However, it seems that the cost of having a global SSR toggle uniform is making the surface shader more expensive (which is already the case, by the way).
- Principle fully black specular tint now returns black instead of white.
- This fixed some artifact issue on my AMD computer on normal surfaces (which might have been some uninitialized variables).
- This touched the Ambient Occlusion because it needs to be evaluated for each closure. But to avoid the cost of this, we use another approach to just pass the result of the occlusion on interpolated normals and modify it using the bent normal for each Closure. This tends to reduce shadowing. I'm still looking into improving this but this is out of the scope of this patch.
- Performance might be a bit worse with this patch since it is more oriented towards code modularity. But not by a lot.
Render tests needs to be updated after this.
Reviewed By: jbakker
Differential Revision: https://developer.blender.org/D10390
# Conflicts:
# source/blender/draw/engines/eevee/eevee_shaders.c
# source/blender/draw/engines/eevee/shaders/common_utiltex_lib.glsl
# source/blender/draw/intern/shaders/common_math_lib.glsl
This patch fix most self intersection comming from reflection rays.
We regenerate the ray if it goes below the shading normal (should be the
geometric normal but we have no access to it here).
Also add the same precision based bias we use for contact shadows.
This fix T81105 Eevee SSR quality regression in 2.91 alpha
- add the use of DRWShaderLibrary to EEVEE's glsl codebase to reduce code
complexity and duplication.
- split bsdf_common_lib.glsl into multiple sub library which are now shared
with other engines.
- the surface shader code is now more organised and have its own files.
- change default world to use a material nodetree and make lookdev shader
more clear.
Reviewed By: jbakker
Differential Revision: https://developer.blender.org/D8306
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
Patch D3205 by Kanzaki Wataru
Only implemented in Eevee for now. Collapse a closure to RGBA so we can
do NPR stuff on the resulting color.
Use an emission shader to convert the color back to a closure.
Doing this will break PBR and will kill any SSR and SSS effects the shader
the shader rely on. That said screen space refraction and ambient occlusion
are supported due to the way they are implemented.
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.
Using GL_RG16I texture for the hit coordinates increase tremendously the precision of the hit.
The sign of the integer is used to 2 flags (has_hit and is_planar).
We do not store the depth and retrieve it from the depth buffer (increasing bandwith by +8bit/px).
The PDF is stored into another GL_R16F texture.
We remove the raycount for simplicity and to reduce compilation time (less branching in refraction shader).
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.
Add sanitizer. I wanted to stay away from this because I think we should fix what causes NaNs in the first place. But there can be too much different factor causing NaNs and it can be because of user inputs.
The branching introduced by the uniform caused problems on mesa + AMD in the resolve stage.
This patch create one shader per sample count without branching.
This improves performance of a single ray per pixel case (3.0ms against 3.6ms in my testing)
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 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.
This was surely cause by float overflow. Limit roughness in this case to limit the brdf intensity.
Also compute VH faster.
Add a sanitizer to the SSR pass for investigating where NANs come from. Play with the roughness until you see where the black pixel is / comes from.
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.
