Blender Git Loki

Merge branch 'master' into cycles-x

Fix runtime CUDA compilation in Cycles X

Caused by recent GPU devices refactor changes: need to install new headers.

Fix crash with Render Layers node after addition of Position pass

Fix black Combined pass when using Denoising Data passes

There is a conflict in the new passes code when having an identical Combined
and Noisy Image pass. For now leave out the Noisy Image pass in this case, it's
not obvious the extra memory and disk space usage is worth the convenience.

Cycles X: abstract new GPU kernels to be less CUDA specific

With the idea of being able to reuse this for HIP and hopefully other devices.
Also cleans up compat.h for CUDA and OptiX a bit and makes them more consistent.

Cycles X: Use display pass directly from Film

Previously the display pass was used from the KernelFilm, which
requires a device update between display pass modification and GPU
display update. Such update is avoidable by using display pass from
film.

With the current state of the code should not be user level changes,
but this allows to have more instant display pass update when GPU
display is used for non-interactive rendering.

Possible improvement would be to separate display pass from node graph
so that change to film's display pass does not cause `device_update`.

Differential Revision: https://developer.blender.org/D12243

Fix Cycles X crash in volume scatter without lights

Check whether there is direct light in the scene before picking a light.

Differential Revision: https://developer.blender.org/D12257

Fix unaligned address CUDA error in Cycles X

Was reproducible with Italian Flat demo file.

Cycles X: add anisotropic random walk SSS

This adds new Subsurface Anisotropy and IOR to the Principled BSDF and
Subsurface Scattering nodes. Real world skin has an anisotropy of around
0.8 and this makes it possible to simulate that more accurately.

Based on the paper: "Path Traced Subsurface Scattering using Anisotropic
Phase Functions and Non-Exponential Free Flights"
https://graphics.pixar.com/library/PathTracedSubsurface/

This comes with a new albedo inversion that gives different results than
the old one. For that reason there is now a Random Walk and Random Walk
(Fixed Radius) option. The latter is provided for backwards compatibility,
and uses the radius exactly as specified. The new one adjust the radius
based on albedo and IOR.

Differential Revision: https://developer.blender.org/D11965

Cleanup: remove a bit more unused diffusion BSSRDF code

Fix pass memory leak in Cycles X

Differential Revision: https://developer.blender.org/D12248

Cycles X: Write all passes on cancel

Makes it possible to cancel rendering and have current state of all
passes written to the render result, matching old behavior.

Differential Revision: https://developer.blender.org/D12246

Fix wrong viewport render when enabling adaptive sampling in Cycles X

Steps to reproduce:
- Start viewport render
- Enable adaptive sampling

Caused by d5019b3838c: integrator's device update did not properly
detect change in sampler and hence did not rebuild the sampler LUT.

Cycles X: remove diffusion / christensen-burley subsurface scattering

Only leaves Random Walk. It has not been decided yet if we will restore
diffusion, but for now remove it to avoid broken options in the UI.

Fix missing Noisy Image pass when using Denoising Data

Make logic consistent between Python and C++ code.

Cycles X: remove legacy Cubic and Gaussian SSS methods

Also some internal refactoring to not have a separate principled BSSRDF
closure, but rather set roughness to FLT_MAX if not using it.

Cleanup: split subsurface scatter function into two

Merge branch 'master' into cycles-x

Merge branch 'master' into cycles-x

Fix crash with render passes in factory startup after adding Position pass