public ObiTriangleMeshHandle GetOrCreateTriangleMesh(Mesh source)
{
ObiTriangleMeshHandle handle = new ObiTriangleMeshHandle(null);
if (source != null && !handles.TryGetValue(source, out handle))
{
var sourceTris = source.triangles;
var sourceVertices = source.vertices;
// Build a bounding interval hierarchy from the triangles:
IBounded[] t = new IBounded[sourceTris.Length / 3];
for (int i = 0; i < t.Length; ++i)
{
int t1 = sourceTris[i * 3];
int t2 = sourceTris[i * 3 + 1];
int t3 = sourceTris[i * 3 + 2];
t[i] = new Triangle(t1, t2, t3, sourceVertices[t1], sourceVertices[t2], sourceVertices[t3]);
}
var sourceBih = BIH.Build(ref t);
Triangle[] tris = Array.ConvertAll(t, x => (Triangle)x);
handle = new ObiTriangleMeshHandle(source, headers.count);
handles.Add(source, handle);
headers.Add(new TriangleMeshHeader(bihNodes.count, sourceBih.Length, triangles.count, tris.Length, vertices.count, sourceVertices.Length));
bihNodes.AddRange(sourceBih);
triangles.AddRange(tris);
vertices.AddRange(sourceVertices);
}
return(handle);
}
public ObiEdgeMeshHandle GetOrCreateEdgeMesh(EdgeCollider2D source)
{
ObiEdgeMeshHandle handle;
if (!handles.TryGetValue(source, out handle))
{
Vector2[] sourceVertices = source.points;
int[] sourceEdges = new int[source.edgeCount * 2];
for (int i = 0; i < source.edgeCount; ++i)
{
sourceEdges[i * 2] = i;
sourceEdges[i * 2 + 1] = i + 1;
}
// Build a bounding interval hierarchy from the edges:
IBounded[] t = new IBounded[source.edgeCount];
for (int i = 0; i < source.edgeCount; ++i)
{
t[i] = new Edge(i, i + 1, sourceVertices[i], sourceVertices[i + 1]);
}
var sourceBih = BIH.Build(ref t);
Edge[] edgs = Array.ConvertAll(t, x => (Edge)x);
handle = new ObiEdgeMeshHandle(source, headers.count);
handles.Add(source, handle);
headers.Add(new EdgeMeshHeader(bihNodes.count, sourceBih.Length, edges.count, edgs.Length, vertices.count, sourceVertices.Length));
bihNodes.AddRange(sourceBih);
edges.AddRange(edgs);
vertices.AddRange(sourceVertices);
}
return(handle);
}
public IEnumerator Generate()
{
nodes.Clear();
if (mesh == null)
yield break;
vertices = mesh.vertices;
int[] triangles = mesh.triangles;
float size = Mathf.Max(mesh.bounds.size.x,mesh.bounds.size.y,mesh.bounds.size.z) + boundsPadding;
Bounds bounds = new Bounds(mesh.bounds.center,Vector3.one*size);
// Use the half-edge structure to generate angle-weighted normals:
HalfEdge he = new HalfEdge(mesh);
if (Application.isPlaying){
CoroutineJob.RunSynchronously(he.Generate()); //While playing, do this synchronously. We don't want to wait too much.
}else{
CoroutineJob generateHalfEdge = new CoroutineJob();
generateHalfEdge.asyncThreshold = 2000; //If this takes more than 2 seconds in the editor, do it asynchronously.
EditorCoroutine.StartCoroutine(generateHalfEdge.Start(he.Generate()));
//Wait for the half-edge generation to complete.
CoroutineJob.ProgressInfo progress = null;
while(!generateHalfEdge.IsDone){
try{
progress = generateHalfEdge.Result as CoroutineJob.ProgressInfo;
}catch(Exception e){
Debug.LogException(e);
yield break;
}
yield return progress;
}
}
//Calculate angle weighted normals, for correct inside/outside determination.
Vector3[] normals = he.AngleWeightedNormals();
yield return new CoroutineJob.ProgressInfo("Building BIH...",0.1f);
// Generate BIH to speed up NN triangle queries.
bih = new BIH();
bih.Generate(bounds,vertices,normals,triangles,8,0.8f);
// Breadth first construction:
Queue<ADFNode> queue = new Queue<ADFNode>();
ADFNode root = new ADFNode(bounds);
queue.Enqueue(root);
nodes.Add(root);
int counter = 0;
while(queue.Count > 0)
{
ADFNode node = queue.Dequeue();
// Here provide an upper-bound estimation of remaining time. Note that in some cases (high maxDepth and high maxError) the process will probably finish sooner than predicted.
if (counter % 10 == 0)
yield return new CoroutineJob.ProgressInfo("Generating distance field level "+node.depth+"...",0.1f + (node.depth/(float)maxDepth)*0.9f);
node.distances = new float[8];
if (highQualityGradient)
node.gradients = new Vector3[8];
// Sample distance at the 8 node corners:
for (int i = 0; i < 8; i++){
BIH.SurfaceInfo si = bih.DistanceToSurface(node.bounds.center + Vector3.Scale(node.bounds.extents,corners[i]));
node.distances[i] = si.signedDistance;
if (highQualityGradient)
node.gradients[i] = si.vectorToSurface;
}
if (node.depth >= maxDepth) continue;
// Measure distances at the 6 node faces, and the center of the node.
float[] realDistances = new float[7];
for (int i = 0; i < 7; i++)
realDistances[i] = bih.DistanceToSurface(node.bounds.center + Vector3.Scale(node.bounds.extents,errorSamples[i] * 0.5f)).signedDistance;
// Get interpolated estimation of distance at the center of possible child nodes:
float[] interpolatedDistances = new float[7];
for (int i = 0; i < 7; i++)
interpolatedDistances[i] = node.SampleDistanceAt(node.bounds.center + Vector3.Scale(node.bounds.extents,errorSamples[i] * 0.5f));
// Calculate mean squared error between measured distances and interpolated ones:
float mse = 0;
for (int i = 0; i < 7; i++){
float d = realDistances[i] - interpolatedDistances[i];
mse += d*d;
}
mse /= 7f;
// If error > threshold, subdivide the node.
if (mse > maxError){
node.children = new int[8];
for (int i = 0; i < 8; i++){
// Calculate child bounds and create the node:
Vector3 childCenter = node.bounds.center + Vector3.Scale(node.bounds.extents,corners[i] * 0.5f);
Vector3 childSize = node.bounds.size*0.5f;
ADFNode child = new ADFNode(new Bounds(childCenter,childSize));
child.depth = node.depth+1;
// Set our children index.
node.children[i] = nodes.Count;
// Add it to nodes list and store it for evaluation.
nodes.Add(child);
queue.Enqueue(child);
}
}
counter++;
}
// Get rid of octree.
bih = null;
}
public static IEnumerator Build(float maxError, int maxDepth, Vector3[] vertexPositions, int[] triangleIndices, List <DFNode> nodes)
{
// Empty vertex or triangle lists, return.
if (maxDepth <= 0 ||
nodes == null ||
vertexPositions == null || vertexPositions.Length == 0 ||
triangleIndices == null || triangleIndices.Length == 0)
{
yield break;
}
// Build a bounding interval hierarchy from the triangles, to speed up distance queries:
IBounded[] t = new IBounded[triangleIndices.Length / 3];
for (int i = 0; i < t.Length; ++i)
{
int t1 = triangleIndices[i * 3];
int t2 = triangleIndices[i * 3 + 1];
int t3 = triangleIndices[i * 3 + 2];
t[i] = new Triangle(t1, t2, t3, vertexPositions[t1], vertexPositions[t2], vertexPositions[t3]);
}
var bih = BIH.Build(ref t);
// Copy reordered triangles over to a new array:
Triangle[] tris = Array.ConvertAll(t, x => (Triangle)x);
// Build angle weighted normals, used to determine the sign of the distance field.
Vector3[] angleNormals = ObiUtils.CalculateAngleWeightedNormals(vertexPositions, triangleIndices);
// Calculate bounding box of the mesh:
Bounds bounds = new Bounds(vertexPositions[0], Vector3.zero);
for (int i = 1; i < vertexPositions.Length; ++i)
{
bounds.Encapsulate(vertexPositions[i]);
}
bounds.Expand(0.1f);
// Auxiliar variables to keep track of current tree depth:
int depth = 0;
int nodesToNextLevel = 1;
// Initialize node list:
Vector4 center = bounds.center;
Vector3 boundsExtents = bounds.extents;
center[3] = Mathf.Max(boundsExtents[0], Math.Max(boundsExtents[1], boundsExtents[2]));
nodes.Clear();
nodes.Add(new DFNode(center));
var queue = new Queue <int>();
queue.Enqueue(0);
while (queue.Count > 0)
{
// get current node:
int index = queue.Dequeue();
var node = nodes[index];
// measure distance at the 8 node corners:
for (int i = 0; i < 8; ++i)
{
Vector4 point = node.center + corners[i] * node.center[3];
point[3] = 0;
float distance = BIH.DistanceToSurface(bih, tris, vertexPositions, angleNormals, point);
if (i < 4)
{
node.distancesA[i] = distance;
}
else
{
node.distancesB[i - 4] = distance;
}
}
// only subdivide those nodes intersecting the surface:
if (depth < maxDepth && Mathf.Abs(BIH.DistanceToSurface(bih, tris, vertexPositions, angleNormals, node.center)) < node.center[3] * sqrt3)
{
// calculate mean squared error between measured distances and interpolated ones:
float mse = 0;
for (int i = 0; i < samples.Length; ++i)
{
Vector4 point = node.center + samples[i] * node.center[3];
float d = BIH.DistanceToSurface(bih, tris, vertexPositions, angleNormals, point) - node.Sample(point);
mse += d * d;
}
mse /= (float)samples.Length;
// if error > threshold, subdivide the node:
if (mse > maxError)
{
node.firstChild = nodes.Count;
for (int i = 0; i < 8; ++i)
{
queue.Enqueue(nodes.Count);
nodes.Add(new DFNode(node.center + corners[i] * node.center[3] * 0.5f));
}
}
// keep track of current depth:
if (--nodesToNextLevel == 0)
{
depth++;
nodesToNextLevel = queue.Count;
}
}
// feed the modified node back:
nodes[index] = node;
yield return(0);
}
}
