private unsafe int BuildBoundingVolume(out NativeArray <BoundingVolumeHierarchy.Node> nodes)
{
// Create inputs
var points = new NativeArray <BoundingVolumeHierarchy.PointAndIndex>(NumChildren, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
var aabbs = new NativeArray <Aabb>(NumChildren, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
for (int i = 0; i < NumChildren; ++i)
{
points[i] = new BoundingVolumeHierarchy.PointAndIndex {
Position = Children[i].CompoundFromChild.pos, Index = i
};
aabbs[i] = Children[i].Collider->CalculateAabb(Children[i].CompoundFromChild);
}
// Build BVH
// Todo: cleanup, better size of nodes array
nodes = new NativeArray <BoundingVolumeHierarchy.Node>(2 + NumChildren, Allocator.Temp, NativeArrayOptions.UninitializedMemory)
{
[0] = BoundingVolumeHierarchy.Node.Empty,
[1] = BoundingVolumeHierarchy.Node.Empty
};
var bvh = new BoundingVolumeHierarchy(nodes);
bvh.Build(points, aabbs, out int numNodes);
return(numNodes);
}
public static unsafe BlobAssetReference <Collider> Create(NativeArray <float3> vertices, NativeArray <int3> triangles, CollisionFilter filter, Material material)
{
SafetyChecks.CheckTriangleIndicesInRangeAndThrow(triangles, vertices.Length, nameof(triangles));
// Copy vertices
var tempVertices = new NativeArray <float3>(vertices, Allocator.Temp);
// Triangle indices - needed for WeldVertices
var tempIndices = new NativeArray <int>(triangles.Reinterpret <int>(UnsafeUtility.SizeOf <int3>()), Allocator.Temp);
// 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);
mesh.UpdateCachedBoundingRadius();
// 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;
}