The issue here is that originally, the step count for the geometry's
motion and the object transform's motion were tied together, so a
single variable is used to store that step count.
However, when using the velocity attribute, it's possible for the step
counts to differ, which will lead to an incorrect interpolated object
transform in the kernel.
Pull Request: https://projects.blender.org/blender/blender/pulls/133788
The issue here is that motion_steps handling is a bit complex, and the
parallel synchronization of geometry does not play well with it.
The obvious result of this was a crash related to the main thread
checking attributes while the geometry sync was changing them, but
there was also another race condition that could result in ending up
with the wrong motion_steps.
Specific changes:
- Change place where `motion_steps` is set to avoid concurrent access
- Change the default `motion_steps` to zero, since they won't be
explicitly set if there's no motion now
- Don't skip `motion_steps` copy in `sync_X` since it's no longer set
in `sync_object` and we need to transfer the value in case it was set
to 3 by the velocity code since that's no longer the default
Pull Request: https://projects.blender.org/blender/blender/pulls/133669
The problem here was that the sync code overwrites the point data, but didn't
reset the transform_applied flag, so the rest of the code assumed that the
points are already in world space and didn't apply the transform again.
Cycles has a sample offset feature allowing users to render X samples
in a single frame on one device, then the remaining Y samples later or
on a different device and combine them back together at the end.
However in most situations the result from using this method was
different, and usually lower quality than rendering all the samples in
one go.
This was because Cycles tunes it's random number sequence for the
number of samples being rendered. And the random number sequence was
being tuned for the wrong number of samples in the case that a user
was using the sample offset.
This commit fixes this issue by adding a "sample subset" feature.
The user specifies the total sample count being rendered across all
devices in the existing `Max Samples` parameter, then specifies per
device which subset of samples will be rendered (E.g. Render samples
0-1024 out of a 0-2048 range).
This commit also contains some additional clean up work
inside Cycles related to the area being changed.
Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/132961
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
Simple local optimization: not doing the rather expensive normals setups
(face and vertex) for Catmull-Clark subsivisions (which do not make use of
these normals and regenerate them internally).
Pull Request: https://projects.blender.org/blender/blender/pulls/132469
Was originally reported in Blender Chat about Cycles standalone
that it will crash when the wrong OCIO configuration path was provided.
More gracefully handle this situation and log a warning instead,
similar to the handling of missing color spaces in the configuration.
The OCIO configuration access could raise an exception when, for example,
the file is missing:
```
ConstConfigRcPtr Config::CreateFromFile(const char * filename)
{
if (!filename || !*filename)
{
throw ExceptionMissingFile ("The config filepath is missing.");
}
...
```
Pull Request: https://projects.blender.org/blender/blender/pulls/132479
The original OSL Shading System API was stateful: You'd create a shader
group, configure it, and then end it. However, this means that only one
group can be created at a time. Further, since Cycles reuses the
Shading System for multiple instances (e.g. viewport render and
material preview), a process-wide mutex is needed.
However, for years now OSL has had a better interface, where you
explicitly provide the group you refer to. With this, we can not only
get rid of the mutex, but actually multi-thread the shader setup even
within one instance.
Realistically, most time is still spent in the JIT stage, but it's
still better than nothing.
Pull Request: https://projects.blender.org/blender/blender/pulls/130133
Based on #123377 by @brecht, but Gitea doesn't like the rebase these
so here's a new PR.
The purpose here is to switch to fused OptiX programs for OSL execution
on CUDA. On the one hand, this makes the code easier since, but there's
also another advantage - how memory allocation is managed.
OSL shaders need memory to store intermediate values, but how much is
needed depends on the complexity of the shader. With the split program
approach, Cycles had to provide that memory, so we had to allocate a
certain amount (2 KiB, to be precise) statically and show an error if
the shader would need more. If the shader used less (which is the case
for the vast majority), the memory was just wasted.
By switching to fused kernels, OSL knows the required amount during JIT
codegen, so it can allocate only what's required, which avoids this
waste. One still needs to set a maximum, and in theory, OSL would also
support spilling over into a Cycles-provided alternative memory region.
However, we currently don't implement that - instead, we default to the
same 2048 limit as before and let advanced users override it via the
CYCLES_OSL_GROUPDATA_ALLOC environment variable if really needed.
Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/130149
- Deduplicate Fisheye projection code
- Replace spherical/cartesian conversions with shared helpers
- Replace transforms from/to local coordinate systems with shared helpers
The main type of repeated transform that's not covered here is `to/from_coords`, but with separate values for xy and z (e.g. BSDFs that already computed `dot(wi, N)` earlier, so they only need `dot(wi, X)` and `dot(wi, Y)` later). Could also be replaced, but it would feel weirdly specific for a helper function.
Pull Request: https://projects.blender.org/blender/blender/pulls/125999
Previously, Cycles only supported the Henyey-Greenstein phase function for volume scattering.
While HG is flexible and works for a wide range of effects, sometimes a more physically accurate
phase function may be needed for realism.
Therefore, this adds three new phase functions to the code:
Rayleigh: For particles with a size below the wavelength of light, mostly athmospheric scattering.
Fournier-Forand: For realistic underwater scattering.
Draine: Fairly specific on its own (mostly for interstellar dust), but useful for the next entry.
Mie: Approximates Mie scattering in water droplets using a mix of Draine and HG phase functions.
These phase functions can be combined using Mix nodes as usual.
Co-authored-by: Lukas Stockner <lukas@lukasstockner.de>
Pull Request: https://projects.blender.org/blender/blender/pulls/123532
Add Metallic BSDF Node to the shader editor.
This node can primarily be used to create more realistic looking
metallic materials than the existing Glossy BSDF node.
This commit does not add any new closures to Cycles, it simply exposes
existing closures that were previous hard to access on their own.
- Exposes the F82 fresnel type that is currently used by the
metallic component of the Principled BSDF. Results should match
between the Metallic BSDF and Principled BSDF when using the same
settings.
- Exposes the Physical Conductor fresnel type that was previously
limited to custom OSL scripts. The Conductor fresnel type accepts
IOR and Extinction coefficients to define the appearance of the
material based off real life measurements.
EEVEE only supports the F82 fresnel type with internal code to convert
the the physical conductor inputs in to a colour format for F82,
which can lead to noticeable rendering differences with
some configurations.
Pull Request: https://projects.blender.org/blender/blender/pulls/114958
Hair objects did not take the curves into account that could go
outside the bounds set by the keys of the curves. These bounds
are used in the dynamic bvh, leading to clipped curves in the
viewport.
Pull Request: https://projects.blender.org/blender/blender/pulls/126157
