Blender Git Loki

Cycles X: sample position on light before stepping through volume

In preparation of equiangular sampling.

Ref D11845

Cycles X: tweak light functions in preparation of equiangular sampling

* Add function to sample a new position on a given light
* Tweak shadow ray generation to be able to override the position

Ref D11845

Cycles X: copy volume phase functions to smaller ShaderVolumePhases struct

Will be important to reduce memory usage in upcoming commits.

Ref D11845

Cycles X: remove all alignment requirements in render passes storage

This saves memory, simplifies the code and has no apparent performance
impact. Whatever historical reasons there were for this, I don't think
they apply anymore.

Differential Revision: https://developer.blender.org/D12015

Fix OpenGL context usage in Cycles X

Activating nullptr context is not a valid way to release the active
context, there is a dedicated function for this.

This also showed a logical error in the buffer mapping: the buffer
unmap is not supposed to release current OpenGL context but should
instead leave it active for a possible subsequent calls to the GPU
update. It worked before because the context as never released due
to wrong API usage.

Would say that the WM OpenGL API should have an assert to catch
such case, but this better to happen in the master branch.

Noticed while doing a further development related to GPUDisplay and
watching return value of GHOST_ActivateOpenGLContext.

Differential Revision: https://developer.blender.org/D11989

Fix missing Noisy Shadow Catcher pass in Cycles X

Differential Revision: https://developer.blender.org/D11987

Cleanup: Remove unused Cycles X passes from list

Fix incorrect denoised shadow catcher pass after last fix

Cleanup: clang-format

Fix various issue with render passes

* Color AOV wrong alpha
* Value AOV not working at all
* Remove unused Denoising Depth pass

Cycles X: restore get_devices() API function

Removal of this broke some render farm scripts. Keep it around for backwards
compatibility but recommend using refresh_devices() instead for refreshing
the device list.

Merge branch 'master' into cycles-x

Cleanup: move ShaderData setup into own file

Cleanup: Spelling in comment and log in Cycles X

No functional changes.

Cycles X: Support approximate shadow catcher with background

On a user-level this change behaves as if the approximate shadow
catcher matte pass is alpha-overed on top of background pass.
This makes it easier to combine artificial objects onto a HDRI
footage.

General idea is to "de-tour" a shadow catcher matte path to the
shade background kernel when needed.

There is some not-so-nice looking scheduling logic after the
intersect closest kernel, which seems to be the best so far from
the performance point of view.

While the shadow catcher performance case might be improved by
avoiding some redundant atomic operations, there is no performance
impact for "regular" case (numbers are on RTX 5000):

```
new cycles-x
bmw27.blend 12.2091 12.2334
classroom.blend 24.2948 24.2565
pabellon.blend 11.1832 11.1941
monster.blend 13.2831 13.1683
barbershop_interior.blend 18.8203 18.904
junkshop.blend 26.5066 26.4452
pvt_flat.blend 22.6359 22.5914
```

There seems to be 2% deviation, sometimes new code is 2% slower,
sometimes it is old code which is 2% slower.

Differential Revision: https://developer.blender.org/D11971

Fix background "leaking" into combined in Cycles X

Was happening when transparent film is enabled, and Environment pass
enabled.

Test file: F10230084

Differential Revision: https://developer.blender.org/D11976

Cleanup: Remove unused pass accessor code

It got re-implemented using `set_render_tile_pixels()`.

Fix wrong MIS weight with transparent surfaces and volumes, leading to noise

Cleanup: move all MIS weighting to integrator/ module

Merge branch 'master' into cycles-x