This is quite basic as it only support boundbing boxes.
But the material can refine the volume shape in anyway the user like.
To overcome this limitation, a voxelisation should be done on the mesh (generating a SDF maybe?) and tested against every volumetric cell.
The system now uses several 3D textures in order to decouple every steps of the volumetric rendering.
See https://www.ea.com/frostbite/news/physically-based-unified-volumetric-rendering-in-frostbite for more details.
On the technical side, instead of using a compute shader to populate the 3D textures we use layered rendering with a geometry shader to render 1 fullscreen triangle per 3D texture slice.
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.
This add the possibility to add screen space raytraced shadows to fix light leaking cause by shadows maps.
Theses inherit of the same artifacts as other screenspace methods.
This required some small changes to the data display shaders so that they match the way the object mode renders them.
Strangely enough, I had to remove the normal attribute from the display code because it was being not bound as soon as I created another rendering call in object mode. The problem may be deeper but I did not have time for this so I derive the normal from the sphere pos.
This adds TAA to eevee. The only thing important to note is that we need to keep the unjittered depth buffer so that the other engines are composited correctly.
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)
You can now use a transparent shader as a completly transparent bsdf. And use whatever alpha mask in a mix shader between a transparent bsdf and another bsdf.
- Replace poisson by concentric samples: Less variance. They are sorted by radius then by angle.
- Separate filtering into 2 blur. First blur is 3x3 box blur. Second is user dependant.
- Group fetches by group of 4.
This brings some data structure changes.
Shared shadow data are stored in ShadowData (in glsl) (aka EEVEE_Shadow in C).
This structure contains the array indices of the first shadow element of this shadow "object".
It also contains how many shadow to evaluate (to be used for Multiple shadow maps).
The filtering is noisy and needs improvement.
- Use only one 2d texture array to store all shadowmaps.
- Allow to change shadow maps resolution.
- Do not output radial distance when rendering shadowmaps. This will allow fast rendering of shadowmaps when we will drop the use of geometry shaders.
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).
It's purpose is to limit the amount of light that spread across the screen.
Not entierly sure if it's very usefull, but it sure help to avoid to drown the screen in bloom.
This function was called to recreate the lower mip level of the probe texture. But this is not it's usage and it introduced a stall.
This patch add cubemap mipmap level regeneration in eevee_effects.c
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).
Diffuse was not outputing the right normal. (this is not a problem with SSR actually)
Glass did not have proper ssr_id and was receiving environment lighting twice.
Also it did not have proper fresnel on lamps.
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.
