Highlights:
* Only allocate and use a wedge map for non-Nanite LODs, or if the mesh is sub 300kindices and it will be cache optimized
* Only allocate and use a remap if there are no overlapping corners
* When the Nanite landscape mesh is created, we now ensure the mesh description is fully compacted, computed, and optimized prior to committing it, along with making sure there are no overlapping corners.
* Since Nanite landscape is checked to ensure no overlapping corners before the build, we can also now skip computing the overlapping corners, which was an intense number of tiny allocations.
* When Nanite landscape is being built as a static mesh, we now avoid super expensive temporary copies of the mesh description, knowing that no actual mutation will occur.
* The original code (after building) would release the memory from the mesh description copy, but it would not release the original immutable cached copy from memory (now that is released too)
* Fixed NaniteLODIndex incorrectly creating a mesh description at a LOD other than the expected 0
* Removed a full loop over all vertex positions by calculating the bounding box while we're building the vertex buffer (and already processing every vertex)
* Added a NeedsCompact() helper to MeshDescription to avoid expensive and unnecessary Compact() calls that do lots of reallocs/copies even if the mesh description is already contiguous\packed in memory.
* Skip building distance field and mesh card representations for the Nanite landscape mesh, which also avoids more cached mesh description deserialization and copies into memory.
Note: In the near future the APIs around this wil be cleaned up further.
#rb richard.talbotwatkin, yuriy.odonnell
[FYI] zousar.shaker, brian.karis, rune.stubbe, juan.canada, danny.couture
#preflight 640b7390482188d710464d39
[CL 24601442 by graham wihlidal in ue5-main branch]
-Nanite-specific settings for tangent and degenerates are no longer also applied to the non-nanite mesh LODs on the same mesh.
-100% fallback meshes now have identical tangents to input mesh. Don't skip the tangent generation in StaticMeshBuilder for these meshes and don't recalculate tangents in Nanite builder.
#preflight 632b04c0b40000c8f0c29adb
#rb brian.karis
[FYI] jamie.hayes, graham.wihlidal
#lockdown marc.audy
[CL 22201439 by rune stubbe in ue5-main branch]
Tangent generation now also respects the Nanite project setting, not just the per-mesh setting.
#lockdown marc.audy
[CL 21862271 by rune stubbe in ue5-main branch]
This represents UE4/Main @17774255, Release-5.0 @17791557 and Dev-PerfTest @17789485
[CL 17794212 by aurel cordonnier in ue5-release-engine-test branch]
This is later used to build static mesh derived data in cases where Nanite coarse mesh representation replaces original static mesh data and we can't depend on it. In extreme cases it lowers main thread derived data build time from ~7.5s to ~0.1s.
#rb Richard.TalbotWatkin
[CL 14578414 by Krzysztof Narkowicz in ue5-main branch]
Prepared direct attribute access for deprecation, preferring use of APIs to access static mesh attributes.
Fixed recently merged Enterprise code to comply with new APIs.
Changed all tools to use triangle-centric iteration where possible.
Added new MeshAttributeArray APIs for querying attribute flags, and added a new Mandatory flag.
Various bug fixes.
#rb Alexis.Matte
[CL 13873755 by Richard TalbotWatkin in ue5-main branch]
- 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-SOURCE: CL 10869240 via CL 10869516 via CL 10869902
#ROBOMERGE-BOT: (v613-10869866)
[CL 10870584 by ryan durand in Main branch]
Clear MeshDescriptions sooner to reduce memory usage on datasmith import
- 37.92 GB -> 26.70 GB Peak Working Set when importing DATASET-0008a
- 66.04 GB -> 52.33 GB Peak Working Set when importing DATASET-0022a
#jira UE-64172
#rb Richard.Talbot-Watkins
#ROBOMERGE-SOURCE: CL 9755311 in //UE4/Release-4.24/...
#ROBOMERGE-BOT: RELEASE (Release-4.24 -> Main) (v545-9751379)
[CL 9755316 by danny couture in Main branch]
