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 leads to a ~3ms improvement of CPU time during drawing.
This prevent the rendering from being stalled waiting for the texture data to be transfered.
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).
Tests on my system with ~1200 objects with 128 shadow casting lamps (current max) show a significant perf improvment (cache timing : 22ms -> 9ms)
With a baseline with no shadow casting light at 6ms this give a reduction of the overhead from 16ms to 3ms.
This remove pretty much all allocations during the cache phase. Leading to a big improvement for scene with a large number of lights & shadowcasters.
The lamps storage has been replace by a union to remove the need to free/allocate everyframe (also reducing memory fragmentation).
We replaced the linked list system used to track shadow casters by a huge bitflag.
We gather the lights shadows bounds as well as the shadow casters AABB during the cache populate phase and put them in big arrays cache friendly.
Then in the cache finish phase, it's easier to iterate over the lamps shadow SphereBounds and test for intersection.
We use a double buffer system for the shadow casters arrays to detect deleted shadow casters.
Unfortunatly, it seems that deleting an object trigger an update for all other objects (thus tagging most shadow casting lamps to update), defeating the purpose of this tracking.
This needs further investigation.
Result is less noisy ogl renders.
What this patch does:
- the draw loops gets accumulated into the output buffer.
- disable TXAA persmat jittering in ogl render since ogl render already does that.
- make noise texture update correct accross all draw loops. Previously it was reset between each FSAA samples.
This augment the existing irradiance grid with a new visibility precomputation.
We store a small shadowmap for each grid sample so that light does not leak through walls and such.
The visibility parameter are similar to the one used by the Variance Shadow Map for point lights.
Technical details:
We store the visibility in the same texture (array) as the irradiance itself (in order to reduce the number of sampler).
But the irradiance and the visibility are not the same data so we must encode them in order to use the same texture format.
We use RGBA8 normalized texture and encode irradiance as RGBE (shared exponent).
Using RGBE encoding instead of R11_G11_B10 may lead to some lighting changes, but quality seems to be nearly the same in my test cases.
Using full RGBA16/32F maybe a future option but that will require much more memory and reduce the perf significantly.
Visibility moments (VSM) are encoded as 16bits fixed point precision using a special range. This seems to retain enough precision for the needs.
Also interpolation does not seems to be big problem (even though it's incorrect).
For functions which will allocate requested data if it does not exist yet
"_ensure" is to be used instead of "_get". "_get" functions should return
NULL in cases when requested data does not exist yet.
This replaces dedicated flag which wasn't clean who sets it and who clears it,
and which was also trying to re-implement existing functionality in a way.
Flushing is not currently very efficient but there are ways to speed this up
a lot, but needs more investigation.
Previously the lighting of SSS material was not present in reflection probe or irradiance grid.
This does not compute the SSS correctly but at least output the corresponding irradiance power to the correct output.
This option prevent from automatically blurring the albedo color applied to the SSS.
While this is great for preserving details it can bleed more light onto the nearby objects since the blurring will be done on pure "white" irradiance.
This issue is to be tackled in a separate commit.
The RenderResult struct still has a listbase of RenderLayer, but that's ok
since this is strictly for rendering.
* Subversion bump (to 2.80.2)
* DNA low level doversion (renames) - only for .blend created since 2.80 started
Note: We can't use DNA_struct_elem_find or get file version in init_structDNA,
so we are manually iterating over the array of the SDNA elements instead.
Note 2: This doversion change with renames can be reverted in a few months. But
so far it's required for 2.8 files created between October 2016 and now.
Reviewers: campbellbarton, sergey
Differential Revision: https://developer.blender.org/D2927
This adds the possibility to simulate things like red ears with strong backlight or material with high scattering distances.
To enable it you need to turn on the "Subsurface Translucency" option in the "Options" tab of the Material Panel (and of course to have "regular" SSS enabled in both render settings and material options).
Since the effect is adding another overhead I prefer to make it optional. But this is open to discussion.
Be aware that the effect only works for direct lights (so no indirect/world lighting) that have shadowmaps, and is affected by the "softness" of the shadowmap and resolution.
Technical notes:
This is inspired by http://www.iryoku.com/translucency/ but goes a bit beyond that.
We do not use a sum of gaussian to apply in regards to the object thickness but we precompute a 1D kernel texture.
This texture stores the light transmited to a point at the back of an infinite slab of material of variying thickness.
We make the assumption that the slab is perpendicular to the light so that no fresnel or diffusion term is taken into account.
The light is considered constant.
If the setup is similar to the one assume during the profile baking, the realtime render matches cycles reference.
Due to these assumptions the computed transmitted light is in most cases too bright for curvy objects.
Finally we jitter the shadow map sample per pixel so we can simulate dispersion inside the medium.
Radius of the dispersion is in world space and derived by from the "soft" shadowmap parameter.
Idea for this come from this presentation http://www.iryoku.com/stare-into-the-future (slide 164).
Samples : pretty self explanatory.
Jitter Threshold : Reduce cache misses and improve performance (greatly) by lowering this value. This settings let user decide how many samples should be jittered (rotated) to reduce banding artifacts.
How to use:
- Enable subsurface scattering in the render options.
- Add Subsurface BSDF to your shader.
- Check "Screen Space Subsurface Scattering" in the material panel options.
This initial implementation has a few limitations:
- only supports gaussian SSS.
- Does not support principled shader.
- The radius parameters is baked down to a number of samples and then put into an UBO. This means the radius input socket cannot be used. You need to tweak the default vector directly.
- The "texture blur" is considered as always set to 1
This also:
- make sure to only compile the shader needed by the active effects.
- same thing for the shading groups.
- disable TAA if motion blur is active (avoid infinite refresh).
It should behave like cycles.
Even if not efficient at all, we still do the same create - draw - free process that was done in the old viewport to save vram (maybe not really the case now) and not care about simulation's GPU texture state sync.
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.
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.
- 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.
