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
Implements the paper [A Microfacet-based Hair Scattering
Model](https://onlinelibrary.wiley.com/doi/full/10.1111/cgf.14588) by
Weizhen Huang, Matthias B. Hullin and Johannes Hanika.
### Features:
- This is a far-field model, as opposed to the previous near-field
Principled Hair BSDF model. The hair is expected to be less noisy, but
lower roughness values takes longer to render due to numerical
integration along the hair width. The hair also appears to be flat when
viewed up-close.
- The longitudinal width of the scattering lobe differs along the
azimuth, providing a higher contrast compared to the evenly spread
scattering in the near-field Principled Hair BSDF model. For a more
detailed comparison, please refer to the original paper.
- Supports elliptical cross-sections, adding more realism as human hairs
are usually elliptical. The orientation of the cross-section is aligned
with the curve normal, which can be adjusted using geometry nodes.
Default is minimal twist. During sampling, light rays that hit outside
the hair width will continue propogating as if the material is
transparent.
- There is non-physical modulation factors for the first three
lobes (Reflection, Transmission, Secondary Reflection).
### Missing:
- A good default for cross-section orientation. There was an
attempt (9039f76928) to default the orientation to align with the curve
normal in the mathematical sense, but the stability (when animated) is
unclear and it would be a hassle to generalise to all curve types. After
the model is in main, we could experiment with the geometry nodes team
to see what works the best as a default.
Co-authored-by: Lukas Stockner <lukas.stockner@freenet.de>
Pull Request: https://projects.blender.org/blender/blender/pulls/105600
Splitting interface stages based on the interpolation of its
attributes.
Then naming convention that have been used:
* use `interp` as instance name when using smooth interpolation
* use `interp_noperspective` when using no perpective interpolation
* use `interp_flat` when using flat interpolation
The same suffix will be added to the struct names.
The naming convention will be added to the GLSL code style and
applied to other shaders as well.
Pull Request: https://projects.blender.org/blender/blender/pulls/111210
This PR adds the Lacunarity and Normalize inputs to the Noise node
similar to the Voronoi node.
The Lacunarity input controls the scale factor by which each
successive Perlin noise octave is scaled. Which was previously hard
coded to a factor of 2.
The Noise node normalizes its output to the [0, 1] range by default.
The Normalize option makes it possible for the user to disable that.
To keep the behavior consistent with past versions it is enabled by
default.
To make the aforementioned normalization control easer to implement,
the fractal noise code now accumulates signed noise and remaps the
final sum, as opposed to accumulating positive [0, 1] noise.
Pull Request: https://projects.blender.org/blender/blender/pulls/110839
Listing the "Blender Foundation" as copyright holder implied the Blender
Foundation holds copyright to files which may include work from many
developers.
While keeping copyright on headers makes sense for isolated libraries,
Blender's own code may be refactored or moved between files in a way
that makes the per file copyright holders less meaningful.
Copyright references to the "Blender Foundation" have been replaced with
"Blender Authors", with the exception of `./extern/` since these this
contains libraries which are more isolated, any changed to license
headers there can be handled on a case-by-case basis.
Some directories in `./intern/` have also been excluded:
- `./intern/cycles/` it's own `AUTHORS` file is planned.
- `./intern/opensubdiv/`.
An "AUTHORS" file has been added, using the chromium projects authors
file as a template.
Design task: #110784
Ref !110783.
