GpuClusterVisibility

Remarks

GpuVisibilityGroup's sibling, and the same three-part arrangement. That one owns the object cull's buffers and dispatch, MeshRenderFeature extracts what it culls, and GpuCullingRenderer puts the dispatch in the frame. This one owns the traversal's buffers and dispatch, VirtualGeometryRenderFeature extracts what it traverses, and ClusterCullingRenderer puts it in the frame. Deliberately the same shape, because it is the same decision at a different depth of the same hierarchy — which is improvement 3 of docs/plan/22-virtualized-geometry.md, and is why the shader is one shader.

Two kinds of buffer, and the difference is what changes. The cluster records, the child runs and the roots are the meshes — they change when a mesh is registered or forgotten, which is a load, not a frame. The instances are the scene — they change when something moves. So the first three are uploaded on a dirty flag and the last through a PersistentUploadBuffer`1, which is phase 0's answer to the same question about objects.

The answer never comes back to the host, and that is the point. What the dispatch writes is a visible-cluster list an indirect draw reads and a request list the residency service reads. Only the second is read back, it is small, and it is read a frame late on purpose — see ServiceRequests.

Fields and properties (40)

• public const int VisiblePerInstance

  How many bytes of visible-cluster list are allocated per instance per view.

• public const int VisibleBase

  How many counter words the visible list carries before its first entry.

• public const uint PageAbsent

  What the slot table holds for a page whose bytes are not in the pool.

• public const int RequestCapacity

  How many page requests one frame's dispatch may record.

• public EffectSystem? Effects

  Where the traversal variant is resolved from. Null does nothing.

• public ComputePipelineCache? Pipelines

  Where the compute pipeline comes from. Null does nothing.

• public HiZPyramid? Occluders

  Last frame's depth, min-reduced, or null to test the frustum and the cone alone.

• public PageResidency? Residency

  Which pages are in the pool. Null traverses as though none are.

• public int MeshCount

  How many meshes are registered.

• public int ClusterCount

  How many clusters they have between them.

• public int PageCount

  How many pages, which is what the slot table has to cover.

• public int PageSize

  How many bytes one page occupies in the pool.

• public int MaximumTriangles

  The most triangles any registered cluster holds.

• public int InstanceCount

  How many instances the last Prepare uploaded.

• public long InstanceBytesUploaded

  How many bytes of instance records it handed to the device.

• public int InstanceUploadRegions

  How many separate writes those bytes took.

• public bool TraversedOnDevice

  Whether the last frame's traversal ran on the device.

• public int VisibleClusters

  How many clusters the last serviced frame's traversal wanted to draw.

• public int SoftwareClusters

  How many of them the software raster was asked to draw.

• public bool VisibleOverflowed

  Whether that count exceeded what the list can hold.

• public int RequestedPages

  How many page requests came back from it.

• public BufferHandle Visible

  The buffer the accepted clusters are appended to: element zero is the count.

• public BufferHandle Requests

  The pages the traversal wanted and did not have. Element zero is the count.

• public BufferHandle Geometry

  Where each cluster's bytes are, for the raster.

• public BufferHandle Grids

  One quantization grid per registered mesh.

• public BufferHandle Materials

  Which material each cluster uses, for the resolve's binning.

• public int MaterialCount

  The highest material index any registered cluster names, plus one.

• public BufferHandle Slots

  Where each page sits in the pool, or PageAbsent.

• public long SlotsOffset

  Where this frame's slot table starts in that buffer.

• public int SlotBase

  Where it starts in entries rather than bytes.

• public BufferHandle Instances

  Where this frame's instance records start.

• public long InstancesOffset
• public int InstanceBase

  Where this frame's instance records start, in records rather than bytes.

• public BufferHandle Bones

  Every skinned instance's matrices, for the raster and the resolve to read.

• public int BoneBase

  Where this frame's palettes start, in matrices rather than bytes.

• public int BoneCount

  How many matrices this frame's palettes hold, including the leading identity.

• public ReadOnlySpan<CullCluster> Records

  The merged cluster records, as the device will read them.

• public ReadOnlySpan<RasterCluster> GeometryRecords

  The merged geometry records, as the raster will read them.

• public ReadOnlySpan<RasterMesh> MeshRecords

  One grid per registered mesh, as the raster and the resolve read them.

• public ReadOnlySpan<CullInstance> InstanceRecords

  This frame's instance records, before they reach the device.

Methods (12)

• public GpuClusterVisibility(IGraphicsDevice device)

  Creates a traversal that runs on a device.

• public ClusterMesh Register(MeshletMesh mesh, MeshletPageSet pages, int source)

  Registers a mesh's DAG, and pins its root page.

• public ClusterMesh MeshAt(int index)

  What a registered mesh's records are, by registration order.

• public void Begin(int count)

  Begins a frame's instance records, keeping what did not change.

• public void BeginBones()

  Begins a frame's bone palettes, discarding the last frame's.

• public int AddBones(ReadOnlySpan<Matrix4x4> palette)

  Adds one instance's palette to this frame's.

• public void Set(int index, in CullInstance instance)

  Sets one instance's record, uploading it only if it differs.

• public void UploadInstances()

  Hands whatever changed to the device.

• public bool Prepare(IReadOnlyList<RenderView> frameViews, ReadOnlySpan<float> errorScale, ReadOnlySpan<float> errorThreshold, ReadOnlySpan<float> softwareThreshold = default(ReadOnlySpan<float>))

  Resolves the variant, uploads what changed, and leaves a dispatch for the frame to record.

• public bool Record(ICommandList list)

  Records the traversal into the frame's own list.

• public int ServiceRequests(int maxLoads = 8)

  Feeds the previous frame's requests to the residency service and lets it work.

• public void Dispose()

  Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

Used by (23)

• VirtualGeometryGameVirtualGeometry
• AssetVirtualGeometrySourceVixen.Engine.Renderer
• BinVixen.Rendering
• ClusterCullingRendererVixen.Rendering
• ClusterRasterTestsVixen.Rendering.Tests
• ClusterResolveTestsVixen.Rendering.Tests
• CompositorAssetTestsVixen.Rendering.Tests
• CompositorBuilderVixen.Rendering
• GpuClusterRasterVixen.Rendering
• GpuClusterResolveVixen.Rendering
• GpuClusterSoftwareRasterVixen.Rendering
• GpuVisibilityTilesVixen.Rendering
• SceneRenderHostTestsVixen.Engine.Renderer.Tests
• SkinnedClusterTestsVixen.Rendering.Tests
• VirtualGeometryContentTestsVixen.Rendering.Tests
• VirtualGeometryDeviceTestsVixen.Graphics.Golden.Tests
• VirtualGeometryFrameTestsVixen.Rendering.Tests
• VirtualGeometryGoldenTestsVixen.Graphics.Golden.Tests
• VirtualGeometryRenderFeatureVixen.Rendering
• VirtualGeometrySystemVixen.Rendering
• VisibilityBufferRendererVixen.Rendering
• VisibilityResolveTestsVixen.Rendering.Tests
• ImportedGeometryLoadsTestsVixen.Editor.Assets.Tests