This commit moves the weld modifier code to the geometry module
so that it can be used in the "Merge by Distance" geometry node
from ec1b0c2014. The "All" mode is exposed in the node
for now, though we could expose the "Connected" mode in the future.
The modifier itself is responsible for creating the selections from
the vertex group. The "All" mode takes an `IndexMask` for the
selection, and the "Connected" mode takes a boolean array,
since it actually iterates over all edges.
Some disabled code for a BVH mode has not been copied over,
it's still accessible through the patches and git history anyway,
and it made the port slightly simpler.
Differential Revision: https://developer.blender.org/D13907
This implements a merge by distance operation for point clouds.
Besides the geometry input, there are two others-- a selection
input to limit the operation to certain points, and the merge
distance. While it would be a reasonable feature, the distance
does not support a field currently, since that would make
the algorithm significantly more complex.
All attributes are merged to the merged points, with the values
mixed together. This same generic method is used for all attributes,
including `position`. The `id` attribute uses the value from the
first merged index for each point.
For the implementation, most of the effort goes into creating a
merge map to speed up attribute mixing. Some parts are inherently
single-threaded, like finding the final indices accounting for the
merged points. By far most of the time is spend balancing the
KD tree.
Mesh support will be added in the next commit.
Differential Revision: https://developer.blender.org/D13649
This patch refactors the instance-realization code and adds new functionality.
* Named and anonymous attributes are propagated from instances to the
realized geometry. If the same attribute exists on the geometry and on an
instance, the attribute on the geometry has precedence.
* The id attribute has special handling to avoid creating the same id on many
output points. This is necessary to make e.g. the Random Value node work
as expected afterwards.
Realizing instance attributes has an effect on existing files, especially due to the
id attribute. To avoid breaking existing files, the Realize Instances node now has
a legacy option that is enabled for all already existing Realize Instances nodes.
Removing this legacy behavior does affect some existing files (although not many).
We can decide whether it's worth to remove the old behavior as a separate step.
This refactor also improves performance when realizing instances. That is mainly
due to multi-threading. See D13446 to get the file used for benchmarking. The
curve code is not as optimized as it could be yet. That's mainly because the storage
for these attributes might change soonish and it wasn't worth optimizing for the
current storage format right now.
```
1,000,000 x mesh vertex: 530 ms -> 130 ms
1,000,000 x simple cube: 1290 ms -> 190 ms
1,000,000 x point: 1000 ms -> 150 ms
1,000,000 x curve spiral: 1740 ms -> 330 ms
1,000,000 x curve line: 1110 ms -> 210 ms
10,000 x subdivided cylinder: 170 ms -> 40 ms
10 x subdivided spiral: 180 ms -> 180 ms
```
Differential Revision: https://developer.blender.org/D13446
This commit adds a fields version of the mesh to curve node, with a
field for the input selection. In order to reduce code duplication,
it adds the mesh to curve conversion to the new geometry module
and calls that implementation from both places.
More details on the geometry module can be found here: T86869
Differential Revision: https://developer.blender.org/D12579
