The problem here was that when direct light contibutions to baking were
disabled, the kernel just skipped all direct lighting evaluation.
However, at secondary bounces, "direct light" would actually end up
being indirect (since there's an extra bounce along the way), but
we're still skipping it.
Therefore, only apply direct lighting skipping at the first bounce.
This fixes an issue where the light tree sampling algorithm would
discard light samples from groups of distance lights with an angle
greater than 0 when it shouldn't.
Pull Request: https://projects.blender.org/blender/blender/pulls/108832
So far, each closure in Cycles was either diffuse OR glossy OR
transmissive, and its color and contributions were assigned
to the corresponding direct/indirect/color passes.
However, since Glass is a single closure now, that is no longer enough,
since glass has both a glossy and a transmissive component.
Therefore, this commit adds support for splitting contributions from
the Glass closure between the two types.
For 4.0, we might want to also use this for Principled Hair since it
also technically has both types, but that would be a change from
the existing result so it's not part of 3.6 yet.
In Embree, tfar modification is taken into account by rtcIntersect1
only when hits are accepted. In order to overcome this, we now check
manually for a max_t value in the filter function.
Pull Request: https://projects.blender.org/blender/blender/pulls/108706
We should be recording only the N closest hits in case the number of
hits is exceeding the maximum allowed or the size of the hits stack.
Previously, some cases made it record hits beyond the furthest recorded
one due to lack of hit distance check.
Only Embree CPU BVH was built in the multi-device case. However, one
Embree GPU BVH is needed per GPU, so we now reuse the same logic as in
the other backends.
Pull Request: https://projects.blender.org/blender/blender/pulls/107992
NanoVDB headers have unused code using "double" type, which is not supported on Arc GPUs.
Recent DPC++ changes enforced runtime verifications:
7663dc201d
which prevents execution when such type has been present even if unused.
This is a solution to avoid double to be compiled at all, similar as how it is done for Metal.
Area light sampling use special techniques to reduce noise with small
spread angles; the change in sampled area was not taken into
consideration when computing the pdf in MNEE.
Pull Request: https://projects.blender.org/blender/blender/pulls/107897
After the removal of the Shadow pass this no longer worked. Now it works by
marking the object as a shadow catcher and returning the Shadow Catcher pass.
The result is different than before, since it also takes into account indirect
light now and uses a different method to weight the contribution of lights that
is adaptive to the light strength.
This will make further changes for light linking easier, where we want to
build multiple trees specialized for each light linking set.
It's also easier to understand than the stack used previously.
Pull Request: https://projects.blender.org/blender/blender/pulls/107560
In some cases comments at the end of control statements were wrapped
onto new lines which made it read as if they applied to the next line
instead of the (now) previous line.
Relocate comments to the previous line or in some cases the end of the
line (before the brace) to avoid confusion.
Note that in quite a few cases these blocks didn't read well
even before MultiLine was used as comments after the brace caused
wrapping across multiple lines in a way that didn't follow
formatting used everywhere else.
There were two issues here preventing the proper display of the IES
files in question.
The primary one was that these lights are actually vertical. Their
profiles actually point upwards from 90deg to 180deg but our parser was
trying hard to adjust it to start at 0deg incorrectly.
Lastly, the files in question ended with the parser in the `eof`
state - they are "missing" the final carriage return that other IES
files tend to have but other viewers don't seem to mind. Change the
`eof` check instead for a better one that will indicate if any parsing
errors occurred along the way.
Pull Request: https://projects.blender.org/blender/blender/pulls/107320
The intersection distance offset in Cycles could have returned
a denormal floating point value for the input values of 0 (and
for the denormal input value).
This could lead to a situation when ray is unable to be advanced
when it hits an edge between two triangles: the intersection will
keep bouncing between two adjacent triangles. This is because the
ray->tmin is compared inclusively, and 0 >= <denormal zero>.
The solution is to return the smallest possible normalized floating
point value from the intersection_t_offset if the input is zero
or a denormal value (which is covered by the same t == 0 check).
This fix is hard to measure on the user level. The old code did
not cause any infinite traversal loop because of the way how the
integration is organized (some kernels offset ray.P, others check
for the number of bounces). It is possible that this fixes some
corner cases of noise: i.e. if some shadow rays falsefully were
considered occluded due to reached maximum number of bounces.
The actual problematic case was discovered during working on a
prototype which had an in-lined intersection loop with the ray
tmin offset.
Pull Request: https://projects.blender.org/blender/blender/pulls/107364
HIP RT enables AMD hardware ray tracing on RDNA2 and above, and falls back to a
to shader implementation for older graphics cards. It offers an average 25%
sample rendering rate improvement in Cycles benchmarks, on a W6800 card.
The ray tracing feature functions are accessed through HIP RT SDK, available on
GPUOpen. HIP RT traversal functionality is pre-compiled in bitcode format and
shipped with the SDK.
This is not yet enabled as there are issues to be resolved, but landing the
code now makes testing and further changes easier.
Known limitations:
* Not working yet with current public AMD drivers.
* Visual artifact in motion blur.
* One of the buffers allocated for traversal has a static size. Allocating it
dynamically would reduce memory usage.
* This is for Windows only currently, no Linux support.
Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Ref #105538
This patch fixes the failing shader/bevel unit test when MetalRT is enabled. The ray was being transformed into local object space even when the SD_OBJECT_TRANSFORM_APPLIED flag was set.
Pull Request: https://projects.blender.org/blender/blender/pulls/107292
When running oneAPI with AoT binaries, on hardware that's not compatible with
these, recompilation could have been missing from the kernels loading phase and
happen during execution instead.
These changes fixes it, any kernel compilation will now happen during the
kernels loading phase.
Using the new HIP SDK 5.5 that includes a fix for the compiler bug.
This also enables the light tree.
For Linux the binaries are still disabled. ROCm 5.5 is planned to
include the same fix but not released yet. When that happens we
should be able to enable Linux as well.
Ref #104786Fix#104085
Pull Request: https://projects.blender.org/blender/blender/pulls/107098
Updated Embree 4 library with GPU support is required for it to be
compiled - compatiblity with Embree 3 and Embree 4 without GPU support
is maintained.
Enabling hardware raytracing is an opt-in user setting for now.
Pull Request: https://projects.blender.org/blender/blender/pulls/106266
This reverts commit df096eab77.
There is a corner case for when WITH_CYCLES_ONEAPI_BINARIES is set to on
and later turned off during config, in case there is no ocloc.
