private static unsafe List <float3> CollectAllVerticesFromSubTree(BoundingVolumeHierarchy.Node *nodes, int subTreeNodeIndex, List <MeshConnectivityBuilder.Primitive> primitives)
{
var vertices = new List <float3>();
int *nodesIndexStack = stackalloc int[BoundingVolumeHierarchy.Constants.UnaryStackSize];
int stackSize = 1;
nodesIndexStack[0] = subTreeNodeIndex;
do
{
BoundingVolumeHierarchy.Node node = nodes[nodesIndexStack[--stackSize]];
if (node.IsLeaf)
{
for (int i = 0; i < 4; i++)
{
if (node.IsChildValid(i))
{
MeshConnectivityBuilder.Primitive p = primitives[node.Data[i]];
vertices.Add(p.Vertices[0]);
vertices.Add(p.Vertices[1]);
vertices.Add(p.Vertices[2]);
if (p.Flags.HasFlag(MeshConnectivityBuilder.PrimitiveFlags.DefaultTrianglePairFlags))
{
vertices.Add(p.Vertices[3]);
}
}
}
}
else
{
for (int i = 0; i < 4; i++)
{
if (node.IsChildValid(i))
{
nodesIndexStack[stackSize++] = node.Data[i];
}
}
}
} while (stackSize > 0);
return(vertices);
}
public static unsafe BlobAssetReference <Collider> Create(NativeArray <float3> vertices, NativeArray <int3> triangles, CollisionFilter filter, Material material)
{
// Copy vertices
var tempVertices = new NativeArray <float3>(vertices, Allocator.Temp);
// Triangle indices - needed for WeldVertices
var tempIndices = new NativeArray <int>(triangles.Length * 3, Allocator.Temp);
for (int iTriangle = 0; iTriangle < triangles.Length; iTriangle++)
{
if (triangles[iTriangle][0] >= 0 && triangles[iTriangle][0] < vertices.Length &&
triangles[iTriangle][1] >= 0 && triangles[iTriangle][1] < vertices.Length &&
triangles[iTriangle][2] >= 0 && triangles[iTriangle][2] < vertices.Length)
{
tempIndices[iTriangle * 3] = triangles[iTriangle][0];
tempIndices[iTriangle * 3 + 1] = triangles[iTriangle][1];
tempIndices[iTriangle * 3 + 2] = triangles[iTriangle][2];
}
else
{
throw new ArgumentException("Tried to create a MeshCollider with indices referencing outside vertex array");
}
}
// Build connectivity and primitives
NativeList <float3> uniqueVertices = MeshConnectivityBuilder.WeldVertices(tempIndices, tempVertices);
var tempTriangleIndices = new NativeArray <int3>(triangles.Length, Allocator.Temp);
UnsafeUtility.MemCpy(tempTriangleIndices.GetUnsafePtr(), tempIndices.GetUnsafePtr(), tempIndices.Length * UnsafeUtility.SizeOf <int>());
var connectivity = new MeshConnectivityBuilder(tempTriangleIndices, uniqueVertices);
NativeList <MeshConnectivityBuilder.Primitive> primitives = connectivity.EnumerateQuadDominantGeometry(tempTriangleIndices, uniqueVertices);
// Build bounding volume hierarchy
int nodeCount = math.max(primitives.Length * 2 + 1, 2); // We need at least two nodes - an "invalid" node and a root node.
var nodes = new NativeArray <BoundingVolumeHierarchy.Node>(nodeCount, Allocator.Temp);
int numNodes = 0;
{
// Prepare data for BVH
var points = new NativeList <BoundingVolumeHierarchy.PointAndIndex>(primitives.Length, Allocator.Temp);
var aabbs = new NativeArray <Aabb>(primitives.Length, Allocator.Temp);
for (int i = 0; i < primitives.Length; i++)
{
MeshConnectivityBuilder.Primitive p = primitives[i];
// Skip degenerate triangles
if (MeshConnectivityBuilder.IsTriangleDegenerate(p.Vertices[0], p.Vertices[1], p.Vertices[2]))
{
continue;
}
aabbs[i] = Aabb.CreateFromPoints(p.Vertices);
points.Add(new BoundingVolumeHierarchy.PointAndIndex
{
Position = aabbs[i].Center,
Index = i
});
}
var bvh = new BoundingVolumeHierarchy(nodes);
bvh.Build(points.AsArray(), aabbs, out numNodes, useSah: true);
}
// Build mesh sections
BoundingVolumeHierarchy.Node *nodesPtr = (BoundingVolumeHierarchy.Node *)nodes.GetUnsafePtr();
MeshBuilder.TempSection sections = MeshBuilder.BuildSections(nodesPtr, numNodes, primitives);
// Allocate collider
int meshDataSize = Mesh.CalculateMeshDataSize(numNodes, sections.Ranges);
int totalColliderSize = Math.NextMultipleOf(sizeof(MeshCollider), 16) + meshDataSize;
MeshCollider *meshCollider = (MeshCollider *)UnsafeUtility.Malloc(totalColliderSize, 16, Allocator.Temp);
// Initialize it
{
UnsafeUtility.MemClear(meshCollider, totalColliderSize);
meshCollider->MemorySize = totalColliderSize;
meshCollider->m_Header.Type = ColliderType.Mesh;
meshCollider->m_Header.CollisionType = CollisionType.Composite;
meshCollider->m_Header.Version += 1;
meshCollider->m_Header.Magic = 0xff;
ref var mesh = ref meshCollider->Mesh;
mesh.Init(nodesPtr, numNodes, sections, filter, material);
// Calculate combined filter
meshCollider->m_Header.Filter = mesh.Sections.Length > 0 ? mesh.Sections[0].Filters[0] : CollisionFilter.Default;
for (int i = 0; i < mesh.Sections.Length; ++i)
{
for (var j = 0; j < mesh.Sections[i].Filters.Length; ++j)
{
var f = mesh.Sections[i].Filters[j];
meshCollider->m_Header.Filter = CollisionFilter.CreateUnion(meshCollider->m_Header.Filter, f);
}
}
meshCollider->m_Aabb = meshCollider->Mesh.BoundingVolumeHierarchy.Domain;
meshCollider->NumColliderKeyBits = meshCollider->Mesh.NumColliderKeyBits;
}
private static unsafe void BuildSectionGeometry(TempSection sections, NativeList <MeshConnectivityBuilder.Primitive> primitives, NativeList <int> subTreeNodeIndices, BoundingVolumeHierarchy.Node *nodes, NativeArray <float3> vertices)
{
var sectionIndex = sections.Ranges.Length;
var newSectionRange = new TempSectionRanges
{
VerticesMin = sections.Vertices.Length,
PrimitivesFlagsMin = sections.PrimitivesFlags.Length,
PrimitivesMin = sections.Primitives.Length
};
sections.Vertices.AddRange(vertices);
int *nodesIndexStack = stackalloc int[BoundingVolumeHierarchy.Constants.UnaryStackSize];
for (var rootIndex = 0; rootIndex < subTreeNodeIndices.Length; ++rootIndex)
{
var root = subTreeNodeIndices[rootIndex];
int stackSize = 1;
nodesIndexStack[0] = root;
do
{
int nodeIndex = nodesIndexStack[--stackSize];
ref BoundingVolumeHierarchy.Node node = ref nodes[nodeIndex];
if (node.IsLeaf)
{
for (int i = 0; i < 4; i++)
{
if (node.IsChildValid(i))
{
MeshConnectivityBuilder.Primitive p = primitives[node.Data[i]];
sections.PrimitivesFlags.Add(ConvertPrimitiveFlags(p.Flags));
int vertexCount = (p.Flags & MeshConnectivityBuilder.PrimitiveFlags.IsTrianglePair) != 0 ? 4 : 3;
Mesh.PrimitiveVertexIndices sectionPrimitive = new Mesh.PrimitiveVertexIndices();
byte *vertexIndices = §ionPrimitive.A;
for (int v = 0; v < vertexCount; v++)
{
vertexIndices[v] = (byte)vertices.IndexOf(p.Vertices[v]);
}
if (vertexCount == 3)
{
sectionPrimitive.D = sectionPrimitive.C;
}
sections.Primitives.Add(sectionPrimitive);
int primitiveSectionIndex = sections.Primitives.Length - newSectionRange.PrimitivesMin - 1;
// Update primitive index in the BVH.
node.Data[i] = (sectionIndex << 8) | primitiveSectionIndex;
}
}
}
else
{
for (int i = 0; i < 4; i++)
{
if (node.IsChildValid(i))
{
nodesIndexStack[stackSize++] = node.Data[i];
}
}
}
} while (stackSize > 0);
}
private static unsafe TempSection BuildSectionGeometry(
int sectionIndex, List <MeshConnectivityBuilder.Primitive> primitives, List <int> subTreeNodeIndices, BoundingVolumeHierarchy.Node *nodes, float3[] vertices)
{
var section = new TempSection();
section.Vertices = vertices.ToList();
section.Primitives = new List <Mesh.PrimitiveVertexIndices>();
section.PrimitivesFlags = new List <Mesh.PrimitiveFlags>();
foreach (int root in subTreeNodeIndices)
{
int *nodesIndexStack = stackalloc int[BoundingVolumeHierarchy.Constants.UnaryStackSize];
int stackSize = 1;
nodesIndexStack[0] = root;
do
{
int nodeIndex = nodesIndexStack[--stackSize];
ref BoundingVolumeHierarchy.Node node = ref nodes[nodeIndex];
if (node.IsLeaf)
{
for (int i = 0; i < 4; i++)
{
if (node.IsChildValid(i))
{
MeshConnectivityBuilder.Primitive p = primitives[node.Data[i]];
section.PrimitivesFlags.Add(ConvertPrimitiveFlags(p.Flags));
int vertexCount = p.Flags.HasFlag(MeshConnectivityBuilder.PrimitiveFlags.IsTrianglePair) ? 4 : 3;
Mesh.PrimitiveVertexIndices sectionPrimitive = new Mesh.PrimitiveVertexIndices();
byte *vertexIndices = §ionPrimitive.A;
for (int v = 0; v < vertexCount; v++)
{
vertexIndices[v] = (byte)Array.IndexOf(vertices, p.Vertices[v]);
}
if (vertexCount == 3)
{
sectionPrimitive.D = sectionPrimitive.C;
}
section.Primitives.Add(sectionPrimitive);
int primitiveSectionIndex = section.Primitives.Count - 1;
// Update primitive index in the BVH.
node.Data[i] = (sectionIndex << 8) | primitiveSectionIndex;
}
}
}
else
{
for (int i = 0; i < 4; i++)
{
if (node.IsChildValid(i))
{
nodesIndexStack[stackSize++] = node.Data[i];
}
}
}
} while (stackSize > 0);
}
// followed by variable sized mesh data
#region Construction
// Create a mesh collider asset from a set of triangles
public static unsafe BlobAssetReference <Collider> Create(float3[] vertices, int[] indices, CollisionFilter?filter = null, Material?material = null)
{
int numVertices = vertices.Length;
int numIndices = indices.Length;
int numTriangles = numIndices / 3;
// Copy vertices
float3[] tempVertices = new float3[numVertices];
Array.Copy(vertices, tempVertices, numVertices);
// Copy indices
int[] tempIndices = new int[numIndices];
for (int iTriangle = 0; iTriangle < numTriangles; iTriangle++)
{
int iIndex0 = iTriangle * 3;
int iIndex1 = iIndex0 + 1;
int iIndex2 = iIndex0 + 2;
tempIndices[iIndex0] = indices[iIndex0];
tempIndices[iIndex1] = indices[iIndex1];
tempIndices[iIndex2] = indices[iIndex2];
}
// Build connectivity and primitives
List <MeshConnectivityBuilder.Primitive> primitives = null;
{
MeshConnectivityBuilder.WeldVertices(tempIndices, ref tempVertices);
var connectivity = new MeshConnectivityBuilder(tempIndices, tempVertices);
primitives = connectivity.EnumerateQuadDominantGeometry(tempIndices, tempVertices);
}
// Build bounding volume hierarchy
var nodes = new NativeArray <BoundingVolumeHierarchy.Node>(primitives.Count * 2 + 1, Allocator.Temp);
int numNodes = 0;
{
// Prepare data for BVH
var points = new NativeArray <BoundingVolumeHierarchy.PointAndIndex>(primitives.Count, Allocator.Temp);
var aabbs = new NativeArray <Aabb>(primitives.Count, Allocator.Temp);
for (int i = 0; i < primitives.Count; i++)
{
MeshConnectivityBuilder.Primitive p = primitives[i];
// Skip degenerate triangles
if (MeshConnectivityBuilder.IsTriangleDegenerate(p.Vertices[0], p.Vertices[1], p.Vertices[2]))
{
continue;
}
aabbs[i] = Aabb.CreateFromPoints(p.Vertices);
points[i] = new BoundingVolumeHierarchy.PointAndIndex
{
Position = aabbs[i].Center,
Index = i
};
}
var bvh = new BoundingVolumeHierarchy(nodes);
bvh.Build(points, aabbs, out numNodes, useSah: true);
points.Dispose();
aabbs.Dispose();
}
// Build mesh sections
BoundingVolumeHierarchy.Node * nodesPtr = (BoundingVolumeHierarchy.Node *)nodes.GetUnsafePtr();
List <MeshBuilder.TempSection> sections = MeshBuilder.BuildSections(nodesPtr, numNodes, primitives);
// Allocate collider
int meshDataSize = Mesh.CalculateMeshDataSize(numNodes, sections);
int totalColliderSize = Math.NextMultipleOf(sizeof(MeshCollider), 16) + meshDataSize;
MeshCollider *meshCollider = (MeshCollider *)UnsafeUtility.Malloc(totalColliderSize, 16, Allocator.Temp);
// Initialize it
{
UnsafeUtility.MemClear(meshCollider, totalColliderSize);
meshCollider->MemorySize = totalColliderSize;
meshCollider->m_Header.Type = ColliderType.Mesh;
meshCollider->m_Header.CollisionType = CollisionType.Composite;
meshCollider->m_Header.Version += 1;
meshCollider->m_Header.Magic = 0xff;
ref var mesh = ref meshCollider->Mesh;
mesh.Init(nodesPtr, numNodes, sections, filter ?? CollisionFilter.Default, material ?? Material.Default);
// Calculate combined filter
meshCollider->m_Header.Filter = mesh.Sections[0].Filters[0];
for (int i = 0; i < mesh.Sections.Length; ++i)
{
foreach (CollisionFilter f in mesh.Sections[i].Filters)
{
meshCollider->m_Header.Filter = CollisionFilter.CreateUnion(meshCollider->m_Header.Filter, f);
}
}
meshCollider->m_Aabb = meshCollider->Mesh.BoundingVolumeHierarchy.Domain;
meshCollider->NumColliderKeyBits = meshCollider->Mesh.NumColliderKeyBits;
}