Adjust clamping of inputs in the Principled BSDF to avoid errors and
inconsistencies between render engines, while trying to leave as many
inputs as possible unclamped for artisitc purposes.
Pull Request: https://projects.blender.org/blender/blender/pulls/112895
The last good commit was 8474716abb.
After this commits from main were pushed to blender-v4.0-release. These are
being reverted.
Commits a4880576dc from to b26f176d1a that happend afterwards were meant for
4.0, and their contents is preserved.
When using Voronoi shader nodes on legacy Intel platforms (HD4400) Blender would crash
due to a driver bug. The bug is related to generating the `fractal_voronoi_x_fx` functions.
It doesn't effect all drivers, but mainly from vendors that don't allow installing the official
intel drivers.
We have tried several approaches including using unique function names and unroll only the
function of the body. But none worked on the failing platform.
In the future we could solve this by including our own GLSL compiler, but that is still very
experimental and requires a lot of testing.#113938
Pull Request: https://projects.blender.org/blender/blender/pulls/113834
The previous formula for adjusting Coat Tint intensity resulted
in strong tints and sudden colour changes when using a low coat weight.
This commit fixes these issues by mixing between a white tint (no tint)
and the chosen tint based on the Coat Weight.
Pull Request: https://projects.blender.org/blender/blender/pulls/113468
This adds correct object bounds estimation.
This works by creating an occupancy texture where one
bit represents one froxel. A geometry pre-pass fill this
occupancy texture and doesn't do any shading. Each bit
set to 0 will not be considered occupied by the object
volume and will discard the material compute shader for
this froxel.
There is 2 method of computing the occupancy map:
- Atomic XOR: For each fragment we compute the amount of
froxels **center** in-front of it. We then convert that
into occupancy bitmask that we apply to the occupancy
texture using `imageAtomicXor`. This is straight forward
and works well for any manifold geometry.
- Hit List: For each fragment we write the fragment depth
in a list (contained in one array texture). This list
is then processed by a fullscreen pass (see
`eevee_occupancy_convert_frag.glsl`) that sorts and
converts all the hits to the occupancy bits. This
emulate Cycles behavior by considering only back-face
hits as exit events and front-face hits as entry events.
The result stores it to the occupancy texture using
bit-wise `OR` operation to compose it with other non-hit
list objects. This also decouple the hit-list evaluation
complexity from the material evaluation shader.
## Limitations
### Fast
- Non-manifolds geometry objects are rendered incorrectly.
- Non-manifolds geometry objects will affect other objects
in front of them.
### Accurate
- Limited to 16 hits per layer for now.
- Non-manifolds geometry objects will affect other objects
in front of them.
Pull Request: https://projects.blender.org/blender/blender/pulls/113731
Replaces all usage by the the gpu_shader_math
equivalent. This is because the old shader
library was quite tangled.
This avoids dependency hell trying to
mix libraries.
Changes are split into isolated commits until
I had to do mass changes because of inter-
dependencies.
Pull Request: https://projects.blender.org/blender/blender/pulls/113631
This add the possibility to create a
orthogonal basis around a given unit
vector.
The name was chosen to match the naming
convention already in place and match
the other matrix construction functions.
In other places (ex: renderers), this same
function is commonly named `make_orthonormal`
or `make_basis`.
The function is not given to have a fixed
implementation and might change overtime.
That's why the test only covers the
assumptions and not the raw values.
The implementation is borrowed from
Cycles and adapted to our math API.
Pull Request: https://projects.blender.org/blender/blender/pulls/113218
Shadow Map Ray Tracing is a technique that ray cast against the shadow
depth buffer. The technique is described in "Soft Shadows by
Ray Tracing Multilayer Transparent Shadow Maps".
Note that we only implement the single layer approach since storing
multiple depth is prohibitively expensive.
Pull Request: https://projects.blender.org/blender/blender/pulls/111809
This avoid confusion outside of the shader node GLSL code.
The issue also is that Metal allow float to cast to bool
implicitly but this create a compilation error on
OpenGL.
This adds a new entry to the split sum LUT to isolate
the effect of the F82 tint.
The application of the tint part is similar to cycles
and uses the same way for precomputing the `b` factor.
Results matches almost perfectly to the extent of the
split sum approximation.
Note that this removes the unused LTC MAG LUT for
EEVEE next to make space for the new table. It can still
be added back if needed.
Pull Request: https://projects.blender.org/blender/blender/pulls/112881
Texture Atomics have been added in Metal 3.1
and enable the original implementations of
shadow update and irradiance cache baking.
However, a fallback solution will be
required for versions under macOS 14.0 utilising
buffer-backed textures instead.
This patch also includes a stub implementation if
building/running on older macOS versions which
provides locally-synchronized texture access in
place of atomics. This enables some effects to be
partially tested, and ensures non-guarded use
of imageAtomic functions does not result
in compilation failure.
Authored by Apple: Michael Parkin-White
Pull Request: https://projects.blender.org/blender/blender/pulls/112866
This keeps the behavior similar to the Disney BRDF, where 0.5
is neutral and lower/higher values respectively decrease/increase
the dielectric specular. But it's more correct in that it's not
an arbitrary scale on Fresnel, but rather adjusting the IOR.
Ref #99447
Ref #112848
Pull Request: https://projects.blender.org/blender/blender/pulls/112552
because it contains reflectance and transmittance, so BSDF would be a
morep proper name.
Also rename BSDF to BRDF at places where only reflectance is returned.
Previously, the Principled BSDF used the Subsurface input to scale the radius.
When it was zero, it used a diffuse closure, otherwise a subsurface closure.
This sort of scaling input makes sense, but it should be specified in distance
units, rather than a 0..1 factor, so this commit changes the unit and renames
the input to Subsurface Scale.
Additionally, it adds support for mixing diffuse and subsurface components.
This is part of e.g. the OpenPBR spec, and the logic behind it is to support
modeling e.g. dirt or paint on top of skin. Before, materials would be either
fully diffuse (radius=0) or fully subsurface.
For typical materials, this mixing factor will be either zero or one
(just like metallic or transmission), but supporting fractional inputs makes
sense for e.g. smooth transitions at boundaries.
Another change is that there is no separate Subsurface Color anymore - before,
this was mixed with the Base Color using the Subsurface input as the factor,
but this was not really useful since that input was generally very small.
And finally, the handling of how the path enters the material for random walk
subsurface scattering is changed. Before, this always used lambertian (diffuse)
transmission, but this caused some problems, like overly white edges.
Instead, two different methods are now used, depending on the selected mode.
In Fixed Radius mode, the code assumes a simple medium boundary, and performs
refraction into the material using the main Roughness and IOR inputs.
Meanwhile, when not using Fixed Radius, the code assumes a more complex
boundary (as typically found on organic materials, e.g. skin), so the entry
bounce has a 50/50 chance of being either diffuse transmission or refraction
using the separate Subsurface IOR input and a fixed roughness of 1.
Credit for this method goes to Christophe Hery.
Pull Request: https://projects.blender.org/blender/blender/pulls/110989
- Adds tint control, which simulates volumetric absorption inside the coating.
This results in angle-dependent saturation and affects all underlying layers
(diffuse, subsurface, metallic, transmission). It provides a physically-based
alternative to ad-hoc effects such as tinted specular highlights.
- Renames the component from "Clearcoat" to "Coat", since it's no longer
necessarily clear now. This matches naming in e.g. other renderers or OpenPBR.
- Adds an explicit Coat IOR input, in preparation for future smarter IOR logic
around the interaction between Coat and main IOR. This used to be hardcoded
to 1.5.
- Removes hardcoded 0.25 weight multiplier, and adds versioning code to update
existing files accordingly. OBJ import/export still applies the factor.
- Replaces the GTR1 microfacet component with regular GGX. This removes a corner
case in the Microfacet code, solves #53038, and makes us more consistent with
other standard surface shaders. The original Disney BSDF used GTR1, but it
doesn't appear that it caught on in the industry.
Co-authored-by: Weizhen Huang <weizhen@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/110993
Schlick's approaximation used by EEVEE is not accurate near `IOR == 1`,
especially when IOR is exactly one, there is no specular reflection and
the material should appear diffuse.
Cycles bypass the issue by lerping between the f0 and f90 color using
the factor derived from real Fresnel curve. In EEVEE we can use the same
trick as in Glass BSDF to smooth the transition at `IOR == 1`.
Note that at `IOR < 1` there is still mismatch, because f0 is prebaked
in the BTDF look up table. In the future if we color f0 using
`specular_tint`, we can split the table and use the BTDF LUT for the
specular component too.
imageStoreFast provides a variant of imageStore which does
not perform any bounds checking, reducing shader divergence,
register pressure and increasing performance through fewer
instructions.
However, this should only be used for cases where the writing
coordinate is guaranteed to fall within the texture.
Authored by Apple: Michael Parkin-White
Pull Request: https://projects.blender.org/blender/blender/pulls/111750
changes include:
* Use microfacet normal instead of macronormal. Previously Cycles used
macronormal for Glass BSDF and Transmission component in Principeld
BSDF, leading to artefacts at grazing angles. This has been corrected
in 5f9b518a8b and 89218b66c2. Now change EEVEE to match this behaviour.
* GGX distribution is now darker due to the shadowing-masking term,
while Multiscatter GGX preserves energy. This now matches Cycles too.
Pull Request: https://projects.blender.org/blender/blender/pulls/111687
When GLSL sources were first included in Blender they were treated as
data (like blend files) and had no license header.
Since then GLSL has been used for more sophisticated features
(EEVEE & real-time compositing)
where it makes sense to include licensing information.
Add SPDX copyright headers to *.glsl files, matching headers used for
C/C++, also include GLSL files in the license checking script.
As leading C-comments are now stripped,
added binary size of comments is no longer a concern.
Ref !111247
Adjust the width, dash length and amount of anti-aliasing of node links
so they look the same independent of the UI scaling.
Adding another parameter to the shader exceeded the limit of 16
attributes. Therefore the parameters to describe the dashes (length,
factor, alpha) are passed in together as a vector.
Ref #102919
Pull Request: https://projects.blender.org/blender/blender/pulls/111270
Fixes NaN in Vector Displacement node caused by the normalization of
0, 0, 0 vectors.
This fixes both visual rendering issues and an "illegal address" error
on the GPU. The "illegal address" error came from the Light Tree
Sampling code not handling the NaN normals well, leading to weird code
paths being taken, eventually leading to a kernel_assert and a
user facing illegal address error.
Pull Request: https://projects.blender.org/blender/blender/pulls/111294
