Blender Git Loki

Merge branch 'master' into soc-2021-uv-editor-improvements

adaptive_cloth: Mesh: split_edge_triangulate(): support for across seams

In the `Mesh` structure, `Edge` stores a tuple of `Vert`s which means,
it is based on the UV coordinates, although this is quite useful,
sometimes it is important to have the mesh operation happen across the
UV seams as well. So consider all the edges formed by the `Vert`s
stored in the `Node` of the given `Edge`'s `Vert`s. Confusing, yes,
but simple.

Fix adaptive sampling with denoising in Cycles X

Writing to the combined pass can not assume that the combined pass has
offset of 0: it is possible that pass at 0 offset is a denoised pass.

Use explicit offset, similar to other places where accumulation to the
combined pass happens.

GPencil: Replace cast

GPencil: (WIP) First steps to implement datablock preview

The preview is not working and Blender keeps locked when closing.

Also, it looks the browser does not display this type.

GPencil: Change menu text

Single-socket input/output nodes in node groups.

Changes the default group input/output nodes in groups to show only
a single socket. This is more convenient for keeping connections short
and put parameters closer to where they are used inside a group.

For input nodes this is purely a UI feature: they can already be
duplicated and unused sockets can be hidden (ctrl+h). The patch only
makes this the default setup of input nodes by providing all inputs
separately in the "Add Node" menu.

For output nodes the situation requires some functional changes,
because outputs have to be unique.

The "virtual" extension socket on group input/output nodes is now
disabled by default, since it adds a lot of visual noise without saving
much work (see discussion in T68733). The feature can be enabled with
a per-node flag.

Todo:
- [ ] Implement unique output handling across different node systems.

Differential Revision: https://developer.blender.org/D11853

GPencil: Add preview var to bGPdata datablock

This preview will be used for assets

GPencil: Add new Asset menu in Edit mode

These options are also available in context menu

Merge branch 'master' into asset-greasepencil

GPencil: Fix merge errors

Replace function names and fix a problem in Offset modifier.

adaptive_cloth: Mesh: append non duplicate vert indices in node.verts

Import changes from code review

Merge branch 'master' into cycles_procedural_api

Merge master into temp-gpencil-bezier-stroke-type

Conflicts:
MOD_gpenciloffset.c

Merge branch 'master' into soc-2021-vse-strip-thumbnails

adaptive_cloth: Mesh: split edge: remove completed todo comment

Fix shadow catcher denoiser after recent changes in Cycles X

The shadow catcher pass access requires combined pass.
This means that the combined pass can not be modified in-place before
the shadow catcher pass is calculated.

Fix crash accessing SHadow Catcher pass without catchers in Cycles X

Merge branch 'master' into soc-2021-uv-editor-improvements