Hans Goudey
482d431bb6
This patch contains an initial set of nodes to access basic mesh topology information, as explored in T100020. The nodes allow six direct topology mappings for meshes: - **Corner -> Face** The face a corner is in, the index in the face - **Vertex -> Edge** Choose an edge attached to the vertex - **Vertex -> Corner** Choose a corner attached to the vertex - **Corner -> Edge** The next and previous edge at each face corner - **Corner -> Vertex** The vertex associated with a corner - **Corner -> Corner** Offset a corner index within a face And two new topology mappings for curves: - **Curve -> Points** Choose a point within a curve - **Point -> Curve** The curve a point is in, the index in the curve The idea is that some of the 16 possible mesh mappings are more important, and that this is a useful set of nodes to start exploring this area. For mappings with an arbitrary number of connections, we must sort them and use an index to choose a single element, because geometry nodes does not support list fields. Note that the sort index has repeating behavior as it goes over the "Total" number of connections, and negative sort indices choose from the end. Currently which of the "start" elements is used is determined by the field context, so the "Field at Index" and "Interpolate Domain" nodes will be quite important. Also, currently the "Sort Index" inputs are clamped to the number of connections. One important feature that isn't implemented here is using the winding order for the output elements. This can be a separate mode for some of these nodes. It will be optional because of the performance impact. There are several todos for separate commits after this: - Rename "Control Point Neighbors" to be consistent with this naming - Version away the "Vertex Neighbors" node which is fully redundant now - Implement a special case for when no weights are used for performance - De-duplicating some of the sorting logic between the nodes - Improve performance and memory use of topology mappings - Look into caching some of the mappings on meshes Differential Revision: https://developer.blender.org/D16029