- Removed hardcoded element type arrays (Vertices, Edges, Triangles etc.). Mesh element types can now be arbitrarily added, with any number of channels.
- Mesh element containers have a much leaner format; instead of sparse arrays, they are now represented by a simple bitarray, determining whether an index is used or not. Consequently, mesh topology is now entirely described with the attribute system, e.g. edge start and end vertices, triangle vertices, etc.
- Support added for attributes of arbitrary dimensions, e.g. float[4] or int[2].
- Support added for attributes which index into another mesh element container.
- Added FMeshElementIndexer: this is an efficient container for maintaining backward references from one element type to another; for example, edges have an attribute specifying which vertices are at each end (an attribute of type FVertexID[2]). With an indexer, it is possible to look up which edges contain a given vertex, even though this is not explicitly stored. Indexers are designed to do minimal allocations and update lazily and in batch when necessary.
- Added support for preserving UV topology in static meshes. UVs are now a first-class element type which may be indexed directly from triangles.
- Added the facility to access the underlying array in an attribute array directly.
- Triangles now directly reference their vertex, edge and UV IDs. Vertex instances are to be deprecated.
- Changed various systems to be triangle-centric rather than polygon-centric, as this is faster. Triangles are presumed to be the elementary face type in a MeshDescription, even if polygons are still supported. The concept of polygons will be somewhat shifted to mean a group of triangles which should be treated collectively for editing purposes.
- Optimised normal/tangent generation and FBX import.
- Deprecated EditableMesh, MeshEditor and StaticMeshEditorExtension plugins - these are to be removed, but they still have certain hooks in place which need removing.
#rb
[CL 13568702 by Richard TalbotWatkin in ue5-main branch]
#rnx
#rb none
#ROBOMERGE-OWNER: ryan.durand
#ROBOMERGE-AUTHOR: ryan.durand
#ROBOMERGE-SOURCE: CL 10869210 via CL 10869511 via CL 10869900
#ROBOMERGE-BOT: (v613-10869866)
[CL 10870549 by ryan durand in Main branch]
- Added a new edge attribute: IsUVSeam.
- Added UMeshDescription::DetermineUVSeamsFromUVs() - to automatically determine which edges are UV seams in the mesh.
- Added edge coloring in the wireframe overlay to show UV seams as well as edge hardness.
#rb none
[CL 3971029 by Richard TalbotWatkin in Dev-Geometry branch]
- Add DDC for to avoid converting many time the same data
#rb none
#codereview richard.talbotwatkin
[CL 3833762 by Alexis Matte in Dev-Geometry branch]
Attributes now have a number of possible types (FVector, FVector4, FVector2D, float, int, bool, FName, UObject*) and are exposed as individual flat arrays, indexed by element ID. For example, vertex positions are essentially exposed as an array of FVector which can be directly accessed and modified. This has a number of advantages:
- It is completely extensible: new attributes can be created (even by a third party) and added to a mesh description without requiring a serialization version bump, or any change to the parent structures.
- This is more efficient in batch operations which deal with a number of mesh elements in one go.
- These attribute buffers can potentially be passed directly to third-party libraries without requiring any kind of transformation.
- The distinct types allow for a better representation of the attribute being specified, without invalid values being possible (cf representing a bool value in an FVector4).
Attributes also have default values, and a flags field which confers use-specific properties to them. Editable Mesh currently uses this to determine whether an attribute's value can be automatically initialized by lerping the values of its neighbours, as well as for identifying auto-generated attributes such as tangents/normals. This is desirable as it means that even unknown / third-party attributes can potentially be handled transparently by Editable Mesh, without requiring the code to be extended.
Certain higher-level operations in EditableMesh have been optimized to make full use of vertex instances where possible.
The welding/splitting of identical vertex instances has been removed from here, as the aim is to unify this with mesh utility code elsewhere.
Various bug fixes.
#rb Alexis.Matte
[CL 3794563 by Richard TalbotWatkin in Dev-Geometry branch]
