Blender Git Loki

Geometry Nodes: initial scattering and geometry nodes

This is the initial merge from the geometry-nodes branch.
Nodes:
* Attribute Math
* Boolean
* Edge Split
* Float Compare
* Object Info
* Point Distribute
* Point Instance
* Random Attribute
* Random Float
* Subdivision Surface
* Transform
* Triangulate

It includes the initial evaluation of geometry node groups in the Geometry Nodes modifier.

Notes on the Generic attribute access API

The API adds an indirection for attribute access. That has the following benefits:
* Most code does not have to care about how an attribute is stored internally.
This is mainly necessary, because we have to deal with "legacy" attributes
such as vertex weights and attributes that are embedded into other structs
such as vertex positions.
* When reading from an attribute, we generally don't care what domain the
attribute is stored on. So we want to abstract away the interpolation that
that adapts attributes from one domain to another domain (this is not
actually implemented yet).

Other possible improvements for later iterations include:
* Actually implement interpolation between domains.
* Don't use inheritance for the different attribute types. A single class for read
access and one for write access might be enough, because we know all the ways
in which attributes are stored internally. We don't want more different internal
structures in the future. On the contrary, ideally we can consolidate the different
storage formats in the future to reduce the need for this indirection.
* Remove the need for heap allocations when creating attribute accessors.

It includes commits from:
* Dalai Felinto
* Hans Goudey
* Jacques Lucke
* L�o Depoix

Geometry Nodes: support geometry components in depsgraph object iterator

Objects can evaluate to a geometry set instead of a single ID (only point cloud
objects for now). In the depsgraph object iterator, the evaluated geometry
components are expanded into temporary objects.

It's important to note that instanced objects can also contain geometry
components. Therefore, they have to be split up into multiple objects
as well in some cases.

At a high level the iterator works like so:

```
for object in depsgraph:
for component in object:
yield object_from_component(component)
for dupli in make_duplis_list(object):
for component in dupli:
yield object_from_component(component)
```

DEG_iterator_objects_next has been cleaned up, to make this structure
a bit more apparent.

This should not change anything for objects that are not point clouds.

Geometry Nodes: support muted nodes

The handling of muted nodes is handled at the derived node tree
level now. This is also where expanding node groups is handled.
Muted nodes are relinked and removed from the derived tree
during construction. The geometry node evaluation code does
not have to know about muted nodes this way.

Geometry Nodes: active modifier + geometry nodes editor

This commit adds functions to set and get the object's active
modifier, which is stored as a flag in the ModifierData struct,
similar to constraints. This will be used to set the context in
the node editor. There are no visible changes in this commit.

Similar to how the node editor context works for materials, this commit
makes the node group displayed in the node editor depend on the active
object and its active modifier. To keep the node group from changing,
just pin the node group in the header.

* Shortcuts performed while there is an active modifier will affect
only that modifier (the exception is the A to expand the modifiers).
* Clicking anywhere on the empty space in a modifier's panel will make it active.

These changes require some refactoring of object modifier code. First
is splitting up the modifier property invoke callback, which now needs
to be able to get the active modifier separately from the hovered
modifier for the different operators.

Second is a change to removing modifiers, where there is now a separate
function to remove a modifier from an object's list, in order to handle
changing the active.

Finally, the panel handler needs a small tweak so that this "click in panel"
event can be handled afterwards.

Geometry Nodes: improve operators for node editor header

This allows users to create new modifiers directly from the
Geometry Nodes Editor.

Preferences: remove Geometry Nodes from experimental

Preferences: remove Point Cloud object from experimental

The point cloud object is the only one that will support instancing at
first. So we can expose it as a regular object.

It is limited since it has no edit mode. But this is not different than
the volume object.

Cleanup: remove most of "#ifdef WITH_GEOMETRY_NODES"

The ones around the simulation datablock are still there, since they are not
needed for the features planned for master yet.

Cleanup: remove all of "#ifdef WITH_POINT_CLOUD"

Since Point Cloud was removed from experimental this is no longer needed.

Geometry Nodes: unify icons -> use ICON_NODETREE for everything

Until there is a icon made specially for this, the nodetree icon is up
for grabs. Using it in the nodegroup + modifier + editor helps the users
to make a connection on where to edit those modifiers.

Fix T83293: crash when selecting bone

This partially reverts rBe922dd7d8a307c54d49bc01649a12610b022192b.
The issues fixed by that commit is still fixed.

Reviewers: fclem

GPU: Show Limited support message for polaris + 20.11.2 drivers.

See T82856 for details.

Deps: Additional changes for PugiXML on macOS

This commit expands the Windows-specific code in rBdca9aa0053f7 and Linux-specific code in rB33b7d53df08a.

It also fixes a capitalization issue in FindPugiXML.cmake

GPU: Blacklist unsupported GPUs that crash during startup.

Since Blender 2.91 the TeraScale 2 based cards crash during startup.
This patch will show the user a screen that the platform they are using
isn't supported.

The GPUs have been carefully handpicked from dozens of reports. T83124,
T83127, T83103, T83091, T83045, T83065, T82750, T82889, T82925, T82640,
T82429, T82436, T82446.

Fix T83161: Crash when moving ruler endpoints and opening or closing the toolshelf

`invert_snap` could be called before `snap_gizmo->keymap` was found.

Use the lazy initialization in `invert_snap` then.

Transform: Correct Mirror for Object Mode along arbitrary axis

This fixes T68521, T82334.

The object are not properly mirrored in object mode.

For mirroring an object that has an arbitrary rotation along the X axis
this is the procedure:
1. mirror x location.
2. negate x scale of the
3. negate y and z component of the rotation (independent of which rotation mode is used).

This knowledge applies now for all angles and axes to finally make the
mirror operation work in object mode.

The new mirror function has the downside that it can not (in this form)
be used with proportional editing.

This is no problem since the old behavior can still be replicated by
scaling with -1 along any axis.

The solution to get perfect mirrors can not work for scaling in general,
because in that case there could be scew created.

Reviewed By: mano-wii

Differential Revision: https://developer.blender.org/D9625

Fix T83119: Crash with topology mirror affecting a hidden vertex

Caused by rBba97da21acf2.

For non-topology mirror hidden verts were never respected/included in
EDBM_verts_mirror_cache_begin (they were excluded from the kdtree).

Prior to said commit, hidden mirrored verts that were still in the map
would have been excluded in a separate loop over vertices in
'editmesh_mirror_data_calc()' by checking BM_ELEM_HIDDEN. Due to the new
nature of this function this check was now moved to
EDBM_verts_mirror_cache_begin.

Maniphest Tasks: T83119

Differential Revision: https://developer.blender.org/D9673

Add Custom Falloff Curve to the Vertex Weight Proximity Modifier.

The Vertex Weight Edit Modifier already got the Custom Curve, there was no
real reason for the proximity not to have it as well.

With some fixes by Bastien Montagne (@mont29).

Reviewed By: mont29

Differential Revision: https://developer.blender.org/D9594

Fix T83300: constant scene refreshing in Cycles with empty volumes

This infinite loop is caused by a conflict between the volume mesh
creation which unintentionally clears the shaders before early exiting
when no grid is found, and the Blender exporter which adds back the
shaders causing us to reupdate as the shaders changed.

To fix this simply preserve the shaders on the Volume node.

Fix build error on builds without audaspace

This was caused by incorrect argument type in dummy function
`rna_Sequences_new_sound()`

Caused by 13ca11ac52a8