The oren_nayar_diffuse_bsdf closure in OSL had two issues:
- It broke when used with roughness of zero
- It only used the provided albedo for energy compensation, so it still
required the user to multiply with the albedo
Therefore, this handles the zero roughness corner case and includes
the albedo in the closure weight.
This makes no difference when using the closure through the Diffuse
or Principled BSDF nodes, only for custom OSL shaders.
Pull Request: https://projects.blender.org/blender/blender/pulls/133597
In a previous commit (1), adjustments to light tree traversal were made
to try and skip distant lights when deciding which light to sample
while within a world volume.
The skip wasn't implemented properly, and as a result distant lights
were still included in the light tree traversal in that sitaution.
And due to the way the skip was implemented, there were some
unintialized variables used in the processing of the distant lights
importance which caused artifacts on some platforms.
This commit fixes this issue by reverting the skip of distant lights
in that situation.
(1) blender/blender@6fbc958e89
Pull Request: https://projects.blender.org/blender/blender/pulls/132344
It is possible that the valid range computed from `theta` and the range
visible to the current pixel do not overlap. In this case the hair
section has no contribution.
Pull Request: https://projects.blender.org/blender/blender/pulls/133337
In Cycles, the subsurface scattering shader will switch to a
diffuse shader under a few different conditions to improve performance
and reduce noise.
This commit removes the "switch back to diffuse if the scattering
radius is less than a quarter of a pixel" optimization because in some
scenes, this can result in noticable lines as the shader transitions
between subsurface scattering and diffuse.
Pull Request: https://projects.blender.org/blender/blender/pulls/133245
Happens after f79cae2c59. Seems that Metal pre-processing could not
figure out that the inclusion is guarded behind `#ifdef`, so the
included file is expanded here and never again afterwards.
The pre-processing should be fixed, but for now just always include the file.
Pull Request: https://projects.blender.org/blender/blender/pulls/133336
The `ZDepth` output of the camera data node was different between SVM
and OSL.
SVM would output the `ZDepth`, with negative distances for points
behind the camera. While OSL would output the absolute of the distance,
which resulted in points behind the camera becoming positive.
Align OSL to SVM and allow outputting the negative distance as it
allows users to differentiate between what's in front or behind the
camera.
Pull Request: https://projects.blender.org/blender/blender/pulls/132837
In a recent refactor (1), the subsurface weight was set to be
constant, when it can be modified in the case that `__SUBSURFACE__`
is false, such as when using the adaptive compilation feature.
This commit fixes this issue by rearranging the code so the subsurface
weight is never overwritten.
(1) blender/blender@dd51c8660b
Pull Request: https://projects.blender.org/blender/blender/pulls/132620
Check was misc-const-correctness, combined with readability-isolate-declaration
as suggested by the docs.
Temporarily clang-format "QualifierAlignment: Left" was used to get consistency
with the prevailing order of keywords.
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
* Use .empty() and .data()
* Use nullptr instead of 0
* No else after return
* Simple class member initialization
* Add override for virtual methods
* Include C++ instead of C headers
* Remove some unused includes
* Use default constructors
* Always use braces
* Consistent names in definition and declaration
* Change typedef to using
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
The Texture Coordinate node has a "Object" output that can be
derived from the object being sampled, or a reference object.
With Cycles OSL, the "Object" output of the Texture Coordinate
would not use the reference object if one was active, and the
node was used on a world shader.
This commit fixes this issue.
Pull Request: https://projects.blender.org/blender/blender/pulls/132515
The output normals of the Texture Coordinate node when using the OSL
backend were not normalized, leading to incorrect values in
some situations.
This commit fixes this issue by normalizing the normals in this situation.
Pull Request: https://projects.blender.org/blender/blender/pulls/132514
The reason for this probably was the const nature of the shader data.
However, this is something counter-intuitive, as it potentially leads
to multiple BSDFs re-using the same LCG state.
Pull Request: https://projects.blender.org/blender/blender/pulls/132456
When a scene contains distant lights and local lights, the first step
of the light tree traversal is to compute the importance of
distant lights vs local lights and pick one based on a random number.
In the specific case of when there is only one distant light,
the line of code that had been changed in this commit
effectively reduced to:
`min_importance = fast_cosf(x) < cosf(x) ? 0.0 : compute_min_importance`
And depending on the hardware, compiler, and the specific value being
tested, different configurations could take different code paths.
This commit fixes this issue by turning the comparison into
`fast_cosf(x) < fast_cosf(x)`.
---
Why does `cos_theta_plus_theta_u < cosf(bcone.theta_e - bcone.theta_o)`
reduce to `fast_cos(x) < cos(x)` in this specific case?
- `cos_theta_plus_theta_u` is computed as
`cos_theta * cos_theta_u - sin_theta * sin_theta_u`
- `cos_theta` is always 1.0 in the case of a single distant light.
- `cos_theta_u` is computed earlier as `fast_cosf(theta_e)` in
`distant_light_tree_parameters()`
- `sin_theta` is zero, and so that side of the equation doesn't matter.
This reduces `cos_theta_plus_theta_u` to `fast_cosf(theta_e)`.
`cosf(bcone.theta_e - bcone.theta_o)` reduces to `cosf(bcone.theta_e)`
because for the case of a single distant light `theta_o` is always 0.
Pull Request: https://projects.blender.org/blender/blender/pulls/131932
Previous implemenation of 5 < d < 50 was taken from the main paper,
fitting for smaller sizes are found in the supplemental. They are less
forward-scattering.
Pull Request: https://projects.blender.org/blender/blender/pulls/130234
`CLOSURE_WEIGHT_CUTOFF` avoids allocating a closure when its weight is
too small. It makes sense for surface closures, but for volume closures
the contribution also depends on the object size/ray length, such a
cutoff seems random and is causing problem in atmospheric scatterings.
Therefore remove the cutoff for volume, just make sure the weight is
positive.
Pull Request: https://projects.blender.org/blender/blender/pulls/131696
The original paper uses the single scattering albedo `sigma_s/sigma_t`
to pick a channel for sampling the scattering distance. However, this
only considers the situation where there is scattering inside the volume.
If some channel has an extinction coefficient of zero, the light passes
through without attenuation for that channel. We assign such channel
with a weight of 1 instead of 0 to make sure it can be sampled.
Pull Request: https://projects.blender.org/blender/blender/pulls/131741
