This never really worked as it was supposed to. The main goal of this is to
turn noise from sampling tiny hairs into multiple layers of transparency that
do not need to be sampled stochastically. However the implementation of this
worked by randomly discarding hair intersections in BVH traversal, which
defeats the purpose.
If it ever comes back, it's best implemented outside the kernel as a preprocess
that changes hair radius before BVH building. This would also make it work with
Embree, where it's not supported now. But it's not so clear anymore that with
many AA samples and GPU rendering this feature is as helpful as it once was for
CPU raytracers with few AA samples.
The benefit of removing this feature is improved hair ray tracing performance,
tested on NVIDIA Titan Xp:
bmw27: +0.37%
classroom: +0.26%
fishy_cat: -7.36%
koro: -12.98%
pabellon: -0.12%
Differential Revision: https://developer.blender.org/D4532
This is only available through the API, mainly intended for render farms to
combine rendered multilayer EXR Files with different samples. The images are
currently expected to have the exact same render layers and passes, just with
different samples.
Variance passes are still simply a weighted average, ideally these should be
merged more intelligently.
Differential Revision: https://developer.blender.org/D4554
It's effectively always enabled, only not on some unsupported OpenCL devices.
For testing those it's not useful to disable these features. This is replaced
by the more fine grained feature toggles that we have now.
The main goals of this change is faster starting when using foreground
rendering.
This patch will build kernels in parallel to the update process of
the scene. When these optimized kernels are not available (yet) an AO
kernel will be used.
These AO kernels are fast to compile (3-7 seconds) and can be
reused by all scenes. When the final kernels become available we
will switch to these kernels.
In background mode the AO kernels will not be used.
Some kernels are being used during Scene update (displace, background
light). When these kernels are being used the process can halt until
these become available.
Reviewed By: brecht, #cycles
Maniphest Tasks: T61752
Differential Revision: https://developer.blender.org/D4428
The NODE_GROUP_LEVEL of the Geometry node should be bumped to 1
when Backface is connected. Backface uses `NODE_LIGHT_PATH` that
is part of NODE_GROUP_LEVEL1, the rest of the geometry ndoe is
NODE_GROUP_LEVEL_0.
This patch will reduce the number of times that we need to
recompile kernels. It does this by (en/dis)abling features
by default. So when the user needs them that the kernels are
already available.
Other features are enabled by default for background and foreground
rendering. When in background rendering the user wants the best
render performance. When in foreground rendering the user wants
the least amount of recompilations.
Enabling volumetrics or subdivision evaluation will still trigger
a recompilation during foreground rendering.
Reviewed By: #cycles, brecht
Differential Revision: https://developer.blender.org/D4485
Float2 are now a new type for attributes in Cycles. Before, the choices
for attribute storage were float and float3, the latter padded to
float4. This meant that UV maps were inflated to twice the size
necessary.
Reviewers: brecht, sergey
Reviewed By: brecht
Subscribers: #cycles
Tags: #cycles
Differential Revision: https://developer.blender.org/D4409
