Made tangent frame consistent across the surface regardless of the sample,
which was not the case with the previous algorithm. Previously, a tangent
frame would stay consistent for the same sample throughout the walk, but not
from sample to sample for the same triangle. This actually resulted in code
simplification.
Also includes additional fixes:
* Fixed an important bug that manifested itself with multiple lights in the
scene, where caustics had abnormally low amplitude: The final light pdf did
not include the light distribution pdf.
* Removed unnecessary orthonormal basis generation function, using cycles'
native one instead.
* Increased solver max iteration back to 64: It turns out we sometimes need
these extra iterations in cases where projection back to the surface takes
many steps. The effective solver iteration count, the most expensive part,
is actually much less than the raw iteration count.
Differential Revision: https://developer.blender.org/D14931
This completes support for tiled texture packing on the Blender / Cycles
side of things.
Most of these changes fall into one of three categories:
- Updating Image handling code to pack/unpack tiled and multi-view images
- Updating Cycles to handle tiled textures through BlenderImageLoader
- Updating OSL to properly handle textures with multiple slots
Differential Revision: https://developer.blender.org/D14395
It was wrongly writing passes twice, for both the surface entry and exit points.
We can skip code for filtering closures, emission and holdout also, as these do
nothing with only a subsurface diffuse closure present.
A shader node setup accidentally used the bump normal as emission. Bump
mapping nodes are excluded from light shader evaluation to reduce kernel size
and register pressure, but in that case should write zero instead of leaving
memory uninitialized.
Thanks to Lukas for helping identify the cause.
Inspired by D12936 and D12929, this patch adds general purpose
"Combine Color" and "Separate Color" nodes to Geometry, Compositor,
Shader and Texture nodes.
- Within Geometry Nodes, it replaces the existing "Combine RGB" and
"Separate RGB" nodes.
- Within Compositor Nodes, it replaces the existing
"Combine RGBA/HSVA/YCbCrA/YUVA" and "Separate RGBA/HSVA/YCbCrA/YUVA"
nodes.
- Within Texture Nodes, it replaces the existing "Combine RGBA" and
"Separate RGBA" nodes.
- Within Shader Nodes, it replaces the existing "Combine RGB/HSV" and
"Separate RGB/HSV" nodes.
Python addons have not been updated to the new nodes yet.
**New shader code**
In node_color.h, color.h and gpu_shader_material_color_util.glsl,
missing methods hsl_to_rgb and rgb_to_hsl are added by directly
converting existing C code. They always produce the same result.
**Old code**
As requested by T96219, old nodes still exist but are not displayed in
the add menu. This means Python scripts can still create them as usual.
Otherwise, versioning replaces the old nodes with the new nodes when
opening .blend files.
Differential Revision: https://developer.blender.org/D14034
The Multiscatter GGX code was missing the same-side checks for incoming and
outgoing directions w.r.t. to shading and geometry normal.
Should not be needed for the Glass variant since it intentionally has both
reflection and transmission.
* Float/double promotion warnings were mainly meant for avoiding slow
operatiosn in the kernel. Limit it to that to avoid hard to fix warnings
in Hydra.
* Const warnings in Hydra iterators.
* Unused variable warnings when building without glog.
* Wrong camera enum comparisons in assert.
* PASS_UNUSED is not a pass type, only for pass offsets.
Currently, the `eval` and `pdf` are not explicitly set to zero when a BSDF sample is invalid (e.g., below the upper hemisphere), when calling
`bsdf_sample` or `bsdf_eval`. It is assumed that `eval` and `pdf` are set to zero before these functions are called, which can cause problems if not.
This patch fixes this potential problem by explicitly setting `eval` and `pdf` to zero when the sampled direction is invalid.
I also added a sanity check if `eval` and `pdf` are valid (i.e., >= 0.f).
The check is activated when build in debug mode and with the `WITH_CYCLES_DEBUG` set to `ON`.
Reviewed By: brecht, sergey
Differential Revision: https://developer.blender.org/D14776
When converting from XYZ to RGB it can happen, in some sky models, that the resulting RGB values are negative.
Atm, this is not considered and the returned values for the sky model can be negative.
This patch clamps the returned RGB values to be `= 0.f`
Reviewed By: brecht, sergey
Differential Revision: https://developer.blender.org/D14777
This is a stripped down version of D14645 without the scene specialisation optimisations.
The two major changes in this patch are:
- Enables more aggressive inlining on Apple Silicon resulting in a 1.1x speedup and 10% reduction in spill, at the cost of longer pipeline build times
- Revival of shader binary archives through a new ShaderCache which is shared between MetalDevice instances using the same physical MTLDevice. This mitigates the extra compile times via explicit caching (rather than, as before, relying on the implicit system shader cache which can be purged without notice)
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D14763
- Add missing doxy-section for Apply Parent Inverse Operator
- Use identity for None comparison in Python.
- Remove newline from operator doc-strings.
- Use '*' prefix multi-line C comment blocks.
- Separate filenames from doc-strings.
- Remove break after return.
Remove need for shadow caustic caster geometry to have a UV layout. UVs were
useful to maintain a consistent tangent frame across the surface while
performing the walk. A consistent tangent frame is necessary for rough
surfaces where a normal offset encodes the sampled h, which should point
towards the same direction across the mesh.
In order to get a continuous surface parametrization without UVs, the
technique described in this paper was implemented:
"The Natural-Constraint Representation of the Path Space for Efficient
Light Transport Simulation" (Supplementary Material), SIGGRAPH 2014.
In addition to implementing this feature:
* Shadow caustic casters without smooth normals are now ignored (triggered
some refactoring and cleaning).
* Hit point calculation was refactored using existing utils functions,
simplifying the code.
* The max number of solver iterations was reduced to 32, a solution is
usually found by then.
* Added generalized geometry term clamping (transfer matrix calculation can
sometimes get unstable).
* Add stop condition to Newton solver for more consistent CPU and GPU result.
* Add support for multi scatter GGX refraction.
Fixes T96990, T96991
Ref T94120
Differential Revision: https://developer.blender.org/D14623
This reverts commit 390b9f1305. It seems to
break things on Linux for unknown reasons, so leave it out for now. A solution
to this will be required for Vega cards though.
This adds support for rendering motion blur for volumes, using their
velocity field. This works for fluid simulations and imported VDB
volumes. For the latter, the name of the velocity field can be set per
volume object, with automatic detection of velocity fields that are
split into 3 scalar grids.
A new parameter is also added to scale velocity for more artistic control.
Like for Alembic and USD caches, a parameter to set the unit of time in
which the velocity vectors are expressed is also added. For Blender gas
simulations, the velocity unit should always be in seconds, so this is
only exposed for volume objects which may come from external OpenVDB
files.
These parameters are available under the `Render` panels for the fluid
domain and the volume object data properties respectively.
Credits: kernel advection code from Tangent Animation's Blackbird based
on earlier work by Geraldine Chua
Differential Revision: https://developer.blender.org/D14629
Keep the existing Rec.709 fit and convert to other colorspace if needed, it
seems accurate enough in practice, and keeps the same performance for the
default case.
As far as I can see, it makes a lot of sense to have the alpha channel here, it matches the 2.x behavior and also matches what Eevee is doing.
Differential Revision: https://developer.blender.org/D14595
This revision allows to specify CUDA host compiler (nvcc's -ccbin command
line option) when configuring the build. It addresses the case where the
C/C++ compiler to be used in CUDA toolchain should be different from the
default C/C++ compiler, for instance in case of compilers versions conflicts
or multiple installed compilers.
The new CMake option is named `CUDA_HOST_COMPILER` and can be used as follows:
`cmake -DCUDA_HOST_COMPILER=<path-to-host-compiler>`
If the option is not specified, the build configuration behaves as previously.
Differential Revision: https://developer.blender.org/D14248
Stumbled over the `integrate_surface_volume_only_bounce` kernel
function not returning the right type. The others too showed up as
warnings when building Cycles as a standalone which didn't have
those warnings disabled.
Differential Revision: https://developer.blender.org/D14558
Light groups are a type of pass that only contains lighting from a subset of light sources.
They are created in the View layer, and light sources (lamps, objects with emissive materials
and/or the environment) can be assigned to a group.
Currently, each light group ends up generating its own version of the Combined pass.
In the future, additional types of passes (e.g. shadowcatcher) might be getting their own
per-lightgroup versions.
The lightgroup creation and assignment is not Cycles-specific, so Eevee or external render
engines could make use of it in the future.
Note that Lightgroups are identified by their name - therefore, the name of the Lightgroup
in the View Layer and the name that's set in an object's settings must match for it to be
included.
Currently, changing a Lightgroup's name does not update objects - this is planned for the
future, along with other features such as denoising for light groups and viewing them in
preview renders.
Original patch by Alex Fuller (@mistaed), with some polishing by Lukas Stockner (@lukasstockner97).
Differential Revision: https://developer.blender.org/D12871
