The scheme solves issues where meshes would no longer align properly after converting them to Nanite. It also solves the precision issues in clusters with triangles of non-uniform size.
By default the precision is heuristically selected by Nanite, but the user also has the ability to override with an explicit precision to solve issues or optimize for disk size.
Clusters store the coordinate components using the minimal number of bits required to span the range of values in the cluster.
Apart from fixing issues, the default quality seems no worse than before and is typically ~5-10% smaller than before.
Added Position Precision to the top left of Mesh viewer along with the other mesh stats.
Added Position Precision dropdown to Nanite import settings.
Added debug mode "r.nanite.visualize PositionBits" that shows the vertex position bit sizes for clusters.
New quantization code now updates float positions and cluster bounds to reflect the quantized coordinates.
#rb brian.karis, graham.wihlidal
#JIRA UE-102722
#preflight 607d56774df3b60001ef477c
[CL 16049335 by Rune Stubbe in ue5-main branch]
* Specifying a flatten material that use VT samplers will automatically create textures of the correct type
* Moved default flatten material to config
* Default is now to use VT for HLOD
#rb jeremy.moore
#jira none
#lockdown simon.tourangeau
#ROBOMERGE-SOURCE: CL 15947766 in //UE5/Release-5.0-EarlyAccess/...
#ROBOMERGE-BOT: STARSHIP (Release-5.0-EarlyAccess -> Main) (v787-15839533)
[CL 15950281 by sebastien lussier in ue5-main branch]
#ROBOMERGE-SOURCE: CL 15867323 in //UE5/Release-5.0-EarlyAccess/...
#ROBOMERGE-BOT: STARSHIP (Release-5.0-EarlyAccess -> Main) (v786-15839533)
[CL 15867336 by daniel wright in ue5-main branch]
* SDFs are now generated, allocated from the atlas and uploaded in 8^3 bricks (7^3 unique data, half voxel padding).
* Tracing must load the brick index from the indirection table, and only bricks near the surface are stored
* 3 mips are now generated, with the lowest resolution always loaded and the other 2 streamed
* SDFs are now G8 narrow band. Lower resolution mips must be traversed when querying distance to nearest surface far away from the surface
* The Distance Field Brick Atlas is now stored for each FScene and dynamically resized based on needs with a GPU memcopy
* Brick atlas uses a 1d pooled allocator which has no fragmentation and greatly reduces packing waste over the 3d allocator
* Added new indirection for Distance Field Asset data, so that only a single entry needs to be updated when a mip is streamed in or out in scenes with millions of instances
* Compute shaders operating on distance field instances generate streaming requests, which are async read back to CPU, turned into IO requests, which are polled and when complete uploaded to atlases
* Any mesh instance inside the Global SDF extent (200m) requests mip1, and at 50m requests mip2
* Now using a batched compute scatter to upload to the distance field atlas instead of RHIUpdateTexture3d, to bypass alignment restrictions and per-upload overhead
* Distance Field streaming uses an async task to move Memcpy and IO request overhead off of the Rendering Thread
* Distance Field Visualization now computes a normal from the SDF gradient and does simple lighting to better visualize the scene representation
* Increased r.DistanceFields.MaxPerMeshResolution from 128 to 512, to better represent large objects
* Mesh SDF generation now uses an Embree point query to calculate closest unsigned distance, and then a much smaller set of rays to count backfaces for negative region determination, for a 11x speedup
* Upgraded mesh utilities to Embree 3.12.2 to get point queries
* Fixed wrong transform used for SDF normals in Lumen, causing non-uniformly scaled meshes to have incorrect Surface Cache interpolation
* Fixed Static Mesh materials not getting PostLoaded before SDF build, causing their blend modes to be wrong for the build, which corrupts the DDC. Also included those blend modes in the DDC key.
Original costs on 1080 GTX (full updates on everything and no screen traces)
10.60ms UpdateGlobalDistanceField
3.62ms LumenReflectiveTest.DirectionalLight_1 Shadowmap 1
1.73ms VoxelizeCards Clipmaps=[0,1,2,3]
0.38ms TraceCards 1 dispatch 1 groups
0.51ms TraceCards 1 dispatch 1 groups
Sparse SDF costs
12.06ms UpdateGlobalDistanceField
4.35ms LumenReflectiveTest.DirectionalLight_1 Shadowmap 1
2.30ms VoxelizeCards Clipmaps=[0,1,2,3]
0.69ms TraceCards 1 dispatch 1 groups
0.77ms TraceCards 1 dispatch 1 groups
Tested: TopazEntry PC, Reverb PC and PS5, EngineTests, QAGame, Rift, Frosty P_Construct_WP, FortGPUTestbed
#rb Krzysztof.Narkowicz
#ROBOMERGE-OWNER: Daniel.Wright
#ROBOMERGE-AUTHOR: daniel.wright
#ROBOMERGE-SOURCE: CL 15784493 in //UE5/Release-5.0-EarlyAccess/...
#ROBOMERGE-BOT: STARSHIP (Release-5.0-EarlyAccess -> Main) (v783-15756269)
#ROBOMERGE-CONFLICT from-shelf
[CL 15790658 by Daniel Wright in ue5-main branch]
Added overlay text for nanite enabled and a warning when the proxy mesh is being displayed
Fixed overlay text creating new widgets every frame
#jira UETOOL-2972
#rb lauren.barnes
#ROBOMERGE-SOURCE: CL 15481409 in //UE5/Release-5.0-EarlyAccess/...
#ROBOMERGE-BOT: STARSHIP (Release-5.0-EarlyAccess -> Main) (v771-15082668)
[CL 15481410 by matt kuhlenschmidt in ue5-main branch]
- Moved source models related classes and implementation into separate files.
- Created a new UObject wrapper for holding mesh description bulk data; this is created as a transactable object inside a UStaticMesh.
- The cached mesh description is now an inner object of the bulk data wrapper; this allows transactions on the bulk data to affect the cached mesh.
- The static mesh SourceModels array can no longer be accessed directly: FStaticMeshSourceModel requires extra initialization before it should be used, so new LODs should be added through the static mesh API.
- Undo/redo is now fixed within the geometry tools
- Fixed regression where mesh description was being unpacked unnecessarily during transactions
- MeshDescription bulk data and its cached MeshDescriptions are now emptied prior to removing the UObject reference, in order to immediately free memory instead of needing to wait for garbage collection
- No more deadlocks when clearing or committing mesh descriptions during garbage collection
- Bulk data UObjects are constructed, where possible, at startup, in order to prevent it from happening during critical moments, e.g. during garbage collection or package saving.
#rb Danny.Couture, Alexis.Matte, Ryan.Schmidt
[CL 15420827 by Richard TalbotWatkin in ue5-main branch]
