- 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
was mixing real geometry normal, smoothed geometry normal and
bump-mapped normal.
Use `(sd->type & PRIMITIVE_CURVE) ? sc->N : sd->Ng` consistently instead.
We already have two other functions doing very much the same thing.
`bsdf_microfacet_sample()` seems to be the only place where this
function was used; there we always sample visible normals, so the extra
`inside` check is not needed.
1. move early-out logic even earlier
2. reduced the scope of some variables
3. return `label` at the end of `bsdf_microfacet_sample()`. Return
`LABEL_NONE` in the invalid case. The previous distinction was
unnecessary because samples with zero contribution are assigned with
`LABEL_NONE` in `integrate_surface_bsdf_bssrdf_bounce()` anyway.
the motivation was to give closures with low weight a higher pdf to pick
at the first bounce, in case the next interaction has high contribution.
However, there are several issues:
1. this is too much fine-tuned for a specific case, and only works well
when there is a strong contribution after reflection and very little
contribution after the transmission;
2. the logic in `bsdf_microfacet.h` was added when merging reflection
and refraction into a glass closure, since then it doesn't even work
well in the above case when mixed with other closures;
3. The behavior is inconsistent in `bsdf_microfacet_eval()` and
`bsdf_microfacet_sample()`;
4. such cases should be handled by more modern and more general methods
such as path guiding and denoiser;
5. it makes the code flow harder to follow
Delete this trick for now to pick the closures solely based on their
`sample_weight`. Can be added back (with proper fix in
`bsdf_microfacet`) if indeed necessary.
Recent versions of DPC++ dropped using the environment variable
SYCL_PI_LEVEL_ZERO_USE_COPY_ENGINE_FOR_IN_ORDER_QUEUE=0 we were setting.
We're now also setting SYCL_PI_LEVEL_ZERO_USE_COPY_ENGINE=0 by default
to keep a consistent behavior.
The API for the kernels library is defined, there is no need to
export more than that. This change only affects linux since hidden
visiblity is the default on Windows.
The recursive building has an early output, which could leave the node
without the requested child initialized, causing the access to the left
child to crash later on in the builder function.
Simply add an extra is-canceled check to avoid access of possibly
non-initialized tree structure.
Pull Request: https://projects.blender.org/blender/blender/pulls/112132
by doing the subtraction first and then take the dot product. This
offers higher precision than taking the dot product first and then
subtract the result, especially in the cases where the ray origin is
very far away from the sphere center.
Curve normal is not available in legacy particle hair system. Construct
a local coordinate system instead of using a fixed normal direction [1,
0, 0] to avoid black appearance.
There are a couple of functions that create rna pointers. For example
`RNA_main_pointer_create` and `RNA_pointer_create`. Currently, those
take an output parameter `r_ptr` as last argument. This patch changes
it so that the functions actually return a` PointerRNA` instead of using
the output parameters.
This has a few benefits:
* Output parameters should only be used when there is an actual benefit.
Otherwise, one should default to returning the value.
* It's simpler to use the API in the large majority of cases (note that this
patch reduces the number of lines of code).
* It allows the `PointerRNA` to be const on the call-site, if that is desired.
No performance regression has been measured in production files.
If one of these functions happened to be called in a hot loop where
there is a regression, the solution should be to use an inline function
there which allows the compiler to optimize it even better.
Pull Request: https://projects.blender.org/blender/blender/pulls/111976
Use the common BVH utilities header for this.
Added a special type qualifier ccl_ray_data which is defined to ccl_private
for all platforms but Metal. On Metal it is defined to ray_data.
The tricky part is that the BVH utilities are wrapped into the Metal context
class. In some of the BVH functions the context has been already constructed,
but it wasn't done in all the callbacks.
From a quick render tests of the Junkshop benchmark scene there is no render
time difference,
No functional changes are expected.
Pull Request: https://projects.blender.org/blender/blender/pulls/111967
The Metal backend combines all kernel sources into a single string
and passes it to the compiler. Doing so natively has a disadvantage
of making it hard to find sources of mistakes in code when working
on the kernel source as the source file name and line number info
is lost. For example, the error would look like:
```
program_source:187004:3: error: use of undeclared identifier 'metalrt_intersection_point_shadow_force_error'
metalrt_intersection_point_shadow_force_error(launch_params_metal,
^
```
This patch makes it so the #line pragmas are inserted into the
combined source source code, so that the compiler errors are easier
to find immediately. For example the error from above becomes
```
source/kernel/device/metal/kernel.metal:809:3: error: use of undeclared identifier 'metalrt_intersection_point_shadow_force_error'
metalrt_intersection_point_shadow_force_error(launch_params_metal,
^
```
The code is a slightly modified functionality from the source
processing used for OpenCL in Blender 2.80.
Pull Request: https://projects.blender.org/blender/blender/pulls/111959
Cycles oneAPI kernel library was compiled using -ffast-math. The current
version of Clang makes it link to crtfastmath.o in that case, bringing a
static constructor that does set the FTZ/DAZ bits in MXCSR for the whole
program, leading to unwanted behavior with other components.
Instead of -ffast-math, we switch to a safer subset of compile flags.
Pull Request: https://projects.blender.org/blender/blender/pulls/111708
based on concentric disk mapping.
Concentric disk mapping was already present, but not used everywhere.
Now `sample_cos_hemisphere()`, `sample_uniform_hemisphere()`, and
`sample_uniform_cone()` use concentric disk mapping.
This changes the noise in many test images.
Pull Request: https://projects.blender.org/blender/blender/pulls/109774
This reverts commit 206ab6437b.
Seems that the illegal address error should be covered elsewhere, but it's not directly
clear where. Revert the commit for further investigation.
Discovered during an investigation into #111277
in rare situations (E.G. When normals are NaN), an emitter
won't be selected as part of `light_tree_cluster_select_emitter()`
and as a result of that, an `emitter_index` of `-1` is passed to
`kernel_data_fetch(light_tree_emitters, emitter_index)` resulting in
an "illegal address" error on some devices.
Pull Request: https://projects.blender.org/blender/blender/pulls/111292
This is in prevision of EEVEE panoramic projection support.
EEVEE-Next is planned to add support for these parameters.
Not having these parameters in Blender DNA will make Cycles
and EEVEE not share the same parameters and will be confusing
for the user.
We handle forward compatibility by still writing the parameters
as ID properties as previous cycles versions expect.
Since this change will break the API compatibility it is crucial
to make it for the 4.0 release.
Related Task #109639
Pull Request: https://projects.blender.org/blender/blender/pulls/111310
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
The `Find*.cmake` modules originally used uppercase commands to match
CMake's own conventions. Since then CMake uses lower-case and even
within our own find modules, using all uppercase wasn't done
consistently. Opt for lowercase everywhere.
