public static int FindClosestFaceOnMesh(Quad[] meshFaces, Vector3[] meshVertexPositions, Vector3 targetPoint)
{
int bestFaceIdx = -1;
float bestFaceDist = float.PositiveInfinity;
for (int faceIdx = 0; faceIdx < meshFaces.Length; ++faceIdx)
{
Quad quad = meshFaces[faceIdx];
for (int i = 0; i < 2; ++i)
{
int vertexIdxA = quad.GetCorner(i + 0);
int vertexIdxB = quad.GetCorner(i + 1);
int vertexIdxC = quad.GetCorner(i + 2);
PointOnMesh closestOnFace = PointOnMesh.MakeClosestToFace(meshVertexPositions, vertexIdxA, vertexIdxB, vertexIdxC, targetPoint);
Vector3 closestOnFacePosition = closestOnFace.AsPosition(meshVertexPositions);
float dist = Vector3.DistanceSquared(targetPoint, closestOnFacePosition);
if (dist < bestFaceDist)
{
bestFaceIdx = faceIdx;
bestFaceDist = dist;
}
}
}
return(bestFaceIdx);
}
public static int[] CalculateTextureToSpatialIndexMap(QuadTopology texturedTopology, Quad[] spatialFaces)
{
int faceCount = texturedTopology.Faces.Length;
if (spatialFaces.Length != faceCount)
{
throw new InvalidOperationException("textured and spatial face count mismatch");
}
int[] spatialIdxMap = new int[texturedTopology.VertexCount];
for (int faceIdx = 0; faceIdx < faceCount; ++faceIdx)
{
Quad texturedFace = texturedTopology.Faces[faceIdx];
Quad spatialFace = spatialFaces[faceIdx];
for (int i = 0; i < Quad.SideCount; ++i)
{
int texturedIdx = texturedFace.GetCorner(i);
int spatialIdx = spatialFace.GetCorner(i);
int previousMapping = spatialIdxMap[texturedIdx];
if (previousMapping != default(int) && previousMapping != spatialIdx)
{
throw new InvalidOperationException("mapping conflict");
}
spatialIdxMap[texturedIdx] = spatialIdx;
}
}
return(spatialIdxMap);
}
private void AssignLabelToConnectedFaces(int label, int faceIdx)
{
int currentLabel = faceLabels[faceIdx];
if (currentLabel == label)
{
return;
}
if (currentLabel != -1)
{
throw new InvalidOperationException("a face cannot be assigned more than one label");
}
faceLabels[faceIdx] = label;
Quad face = faces[faceIdx];
for (int cornerIdx = 0; cornerIdx < Quad.SideCount; ++cornerIdx)
{
int vertexIdx = face.GetCorner(cornerIdx);
foreach (int adjacentFaceIdx in adjacentFacesByVertex[vertexIdx])
{
AssignLabelToConnectedFaces(label, adjacentFaceIdx);
}
}
}
/**
* Given two topologies with the same faces but different vertex indices, returns a map from the vertex
* indices of one topology to the vertex indices of the other topologies.
*
* Each vertex in the source topology must map to a single vertex in the dest topology. However, it's
* allowable for multiple source vertices to map to the same dest vertex. Thus it's possible to map
* from a source UV topology with seams to a dest spatial topology without seams.
*/
public static int[] CalculateVertexIndexMap(QuadTopology sourceTopology, Quad[] destFaces)
{
int faceCount = sourceTopology.Faces.Length;
if (destFaces.Length != faceCount)
{
throw new InvalidOperationException("face count mismatch");
}
int[] indexMap = new int[sourceTopology.VertexCount];
for (int faceIdx = 0; faceIdx < faceCount; ++faceIdx)
{
Quad sourceFace = sourceTopology.Faces[faceIdx];
Quad destFace = destFaces[faceIdx];
for (int i = 0; i < Quad.SideCount; ++i)
{
int sourceIdx = sourceFace.GetCorner(i);
int destIdx = destFace.GetCorner(i);
int previousMapping = indexMap[sourceIdx];
if (previousMapping != default(int) && previousMapping != destIdx)
{
throw new InvalidOperationException("mapping conflict");
}
indexMap[sourceIdx] = destIdx;
}
}
return(indexMap);
}
private void FillAdjancencyTable()
{
for (int faceIdx = 0; faceIdx < faces.Length; ++faceIdx)
{
Quad face = faces[faceIdx];
for (int cornerIdx = 0; cornerIdx < Quad.SideCount; ++cornerIdx)
{
adjacentFacesByVertex[face.GetCorner(cornerIdx)].Add(faceIdx);
}
}
}