float Cut(Mesh mesh, Transform meshTransform, Math.Plane plane, bool triangulateHoles, bool allowOpenMesh, ref List<CutterMesh> meshes)
{
var stopWatch = new Stopwatch();
stopWatch.Start();
#if PROFILING
MeasureIt.Begin("CutAllocations");
#endif
// cache mesh data
var trianglesNum = mesh.triangles.Length;
var verticesNum = mesh.vertices.Length;
var meshTriangles = mesh.triangles;
var meshTangents = mesh.tangents;
var meshColors = mesh.colors32;
var meshVertices = mesh.vertices;
var meshNormals = mesh.normals;
var meshUV = mesh.uv;
var useMeshTangents = meshTangents != null && meshTangents.Length > 0;
var useVertexColors = meshColors != null && meshColors.Length > 0;
var useNormals = meshNormals != null && meshNormals.Length > 0;
// preallocate buffers
AllocateBuffers(trianglesNum, verticesNum, useMeshTangents, useVertexColors);
CutterMesh mesh0, mesh1;
#if PROFILING
MeasureIt.End("CutAllocations");
MeasureIt.Begin("CutCycleFirstPass");
#endif
// inverse transform cutting plane
plane.InverseTransform(meshTransform);
// first pass - find complete triangles on both sides of the plane
for (int i = 0; i < trianglesNum; i += 3)
{
// get triangle points
var v0 = meshVertices[meshTriangles[i]];
var v1 = meshVertices[meshTriangles[i + 1]];
var v2 = meshVertices[meshTriangles[i + 2]];
var side0 = plane.GetSideFix(ref v0);
var side1 = plane.GetSideFix(ref v1);
var side2 = plane.GetSideFix(ref v2);
meshVertices[meshTriangles[i]] = v0;
meshVertices[meshTriangles[i + 1]] = v1;
meshVertices[meshTriangles[i + 2]] = v2;
// Utils.Log(plane.Pnt + " " + v0 + " " + v1 + " " + " " + v2);
// all points on one side
if (side0 == side1 && side1 == side2)
{
var idx = side0 ? 0 : 1;
if (meshTriangles[i] >= triCache.Length)
{
ExploderUtils.Log("TriCacheError " + meshTriangles[i] + " " + triCache.Length + " " + meshVertices.Length);
}
if (triCache[meshTriangles[i]] == 0)
{
triangles[idx].Add(triCounter[idx]);
vertices[idx].Add(meshVertices[meshTriangles[i]]);
uvs[idx].Add(meshUV[meshTriangles[i]]);
if (useNormals)
{
normals[idx].Add(meshNormals[meshTriangles[i]]);
}
if (useMeshTangents)
{
tangents[idx].Add(meshTangents[meshTriangles[i]]);
}
if (useVertexColors)
{
vertexColors[idx].Add(meshColors[meshTriangles[i]]);
}
centroid[idx] += meshVertices[meshTriangles[i]];
triCache[meshTriangles[i]] = triCounter[idx] + 1;
triCounter[idx]++;
}
else
{
triangles[idx].Add(triCache[meshTriangles[i]] - 1);
}
if (triCache[meshTriangles[i + 1]] == 0)
{
triangles[idx].Add(triCounter[idx]);
vertices[idx].Add(meshVertices[meshTriangles[i + 1]]);
uvs[idx].Add(meshUV[meshTriangles[i + 1]]);
if (useNormals)
{
normals[idx].Add(meshNormals[meshTriangles[i + 1]]);
}
if (useMeshTangents)
{
tangents[idx].Add(meshTangents[meshTriangles[i+1]]);
}
if (useVertexColors)
{
vertexColors[idx].Add(meshColors[meshTriangles[i+1]]);
}
centroid[idx] += meshVertices[meshTriangles[i + 1]];
triCache[meshTriangles[i + 1]] = triCounter[idx] + 1;
triCounter[idx]++;
}
else
{
triangles[idx].Add(triCache[meshTriangles[i + 1]] - 1);
}
if (triCache[meshTriangles[i + 2]] == 0)
{
triangles[idx].Add(triCounter[idx]);
vertices[idx].Add(meshVertices[meshTriangles[i + 2]]);
uvs[idx].Add(meshUV[meshTriangles[i + 2]]);
if (useNormals)
{
normals[idx].Add(meshNormals[meshTriangles[i + 2]]);
}
if (useMeshTangents)
{
tangents[idx].Add(meshTangents[meshTriangles[i+2]]);
}
if (useVertexColors)
{
vertexColors[idx].Add(meshColors[meshTriangles[i+2]]);
}
centroid[idx] += meshVertices[meshTriangles[i + 2]];
triCache[meshTriangles[i + 2]] = triCounter[idx] + 1;
triCounter[idx]++;
}
else
{
triangles[idx].Add(triCache[meshTriangles[i + 2]] - 1);
}
}
else
{
// intersection triangles add to list and process it in second pass
cutTris.Add(i);
}
}
if (vertices[0].Count == 0)
{
centroid[0] = meshVertices[0];
}
else
{
centroid[0] /= vertices[0].Count;
}
if (vertices[1].Count == 0)
{
centroid[1] = meshVertices[1];
}
else
{
centroid[1] /= vertices[1].Count;
}
#if PROFILING
MeasureIt.End("CutCycleFirstPass");
MeasureIt.Begin("CutCycleSecondPass");
#endif
mesh0.centroid = centroid[0];
mesh1.centroid = centroid[1];
mesh0.mesh = null;
mesh1.mesh = null;
if (cutTris.Count < 1)
{
stopWatch.Stop();
return stopWatch.ElapsedMilliseconds;
}
AllocateContours(cutTris.Count);
// second pass - cut intersecting triangles in half
foreach (var cutTri in cutTris)
{
var triangle = new Triangle
{
ids = new[] { meshTriangles[cutTri + 0], meshTriangles[cutTri + 1], meshTriangles[cutTri + 2] },
pos = new[] { meshVertices[meshTriangles[cutTri + 0]], meshVertices[meshTriangles[cutTri + 1]], meshVertices[meshTriangles[cutTri + 2]] },
normal = useNormals ? new[] { meshNormals[meshTriangles[cutTri + 0]], meshNormals[meshTriangles[cutTri + 1]], meshNormals[meshTriangles[cutTri + 2]] } : new[] { Vector3.zero, Vector3.zero, Vector3.zero },
uvs = new[] { meshUV[meshTriangles[cutTri + 0]], meshUV[meshTriangles[cutTri + 1]], meshUV[meshTriangles[cutTri + 2]] },
tangents = useMeshTangents ? new[] { meshTangents[meshTriangles[cutTri + 0]], meshTangents[meshTriangles[cutTri + 1]], meshTangents[meshTriangles[cutTri + 2]]} : new []{ Vector4.zero, Vector4.zero, Vector4.zero },
colors = useVertexColors ? new[] { meshColors[meshTriangles[cutTri + 0]], meshColors[meshTriangles[cutTri + 1]], meshColors[meshTriangles[cutTri + 2]] } : new Color32[] { Color.white, Color.white, Color.white },
};
// check points with a plane
var side0 = plane.GetSide(triangle.pos[0]);
var side1 = plane.GetSide(triangle.pos[1]);
var side2 = plane.GetSide(triangle.pos[2]);
float t0, t1;
Vector3 s0 = Vector3.zero, s1 = Vector3.zero;
var idxLeft = side0 ? 0 : 1;
var idxRight = 1 - idxLeft;
if (side0 == side1)
{
var a = plane.IntersectSegment(triangle.pos[2], triangle.pos[0], out t0, ref s0);
var b = plane.IntersectSegment(triangle.pos[2], triangle.pos[1], out t1, ref s1);
ExploderUtils.Assert(a && b, "!!!!!!!!!!!!!!!");
// left side ... 2 triangles
var s0Left = AddIntersectionPoint(s0, triangle, triangle.ids[2], triangle.ids[0], cutVertCache[idxLeft], vertices[idxLeft], normals[idxLeft], uvs[idxLeft], tangents[idxLeft], vertexColors[idxLeft], useMeshTangents, useVertexColors, useNormals);
var s1Left = AddIntersectionPoint(s1, triangle, triangle.ids[2], triangle.ids[1], cutVertCache[idxLeft], vertices[idxLeft], normals[idxLeft], uvs[idxLeft], tangents[idxLeft], vertexColors[idxLeft], useMeshTangents, useVertexColors, useNormals);
var v0Left = AddTrianglePoint(triangle.pos[0], triangle.normal[0], triangle.uvs[0], triangle.tangents[0], triangle.colors[0], triangle.ids[0], triCache, cornerVertCache[idxLeft], vertices[idxLeft], normals[idxLeft], uvs[idxLeft], tangents[idxLeft], vertexColors[idxLeft], useMeshTangents, useVertexColors, useNormals);
var v1Left = AddTrianglePoint(triangle.pos[1], triangle.normal[1], triangle.uvs[1], triangle.tangents[1], triangle.colors[1], triangle.ids[1], triCache, cornerVertCache[idxLeft], vertices[idxLeft], normals[idxLeft], uvs[idxLeft], tangents[idxLeft], vertexColors[idxLeft], useMeshTangents, useVertexColors, useNormals);
// Triangle (s0, v0, s1)
triangles[idxLeft].Add(s0Left);
triangles[idxLeft].Add(v0Left);
triangles[idxLeft].Add(s1Left);
// Triangle (s1, v0, v1)
triangles[idxLeft].Add(s1Left);
triangles[idxLeft].Add(v0Left);
triangles[idxLeft].Add(v1Left);
// right side ... 1 triangle
var s0Right = AddIntersectionPoint(s0, triangle, triangle.ids[2], triangle.ids[0], cutVertCache[idxRight], vertices[idxRight], normals[idxRight], uvs[idxRight], tangents[idxRight], vertexColors[idxRight], useMeshTangents, useVertexColors, useNormals);
var s1Right = AddIntersectionPoint(s1, triangle, triangle.ids[2], triangle.ids[1], cutVertCache[idxRight], vertices[idxRight], normals[idxRight], uvs[idxRight], tangents[idxRight], vertexColors[idxRight], useMeshTangents, useVertexColors, useNormals);
var v2Right = AddTrianglePoint(triangle.pos[2], triangle.normal[2], triangle.uvs[2], triangle.tangents[2], triangle.colors[2], triangle.ids[2], triCache, cornerVertCache[idxRight], vertices[idxRight], normals[idxRight], uvs[idxRight], tangents[idxRight], vertexColors[idxRight], useMeshTangents, useVertexColors, useNormals);
// Triangle (v2, s0, s1)
triangles[idxRight].Add(v2Right);
triangles[idxRight].Add(s0Right);
triangles[idxRight].Add(s1Right);
// buffer intersection vertices for triangulation
if (triangulateHoles)
{
if (idxLeft == 0)
{
contour.AddTriangle(cutTri, s0Left, s1Left, s0, s1);
}
else
{
contour.AddTriangle(cutTri, s0Right, s1Right, s0, s1);
}
}
}
else if (side0 == side2)
{
var a = plane.IntersectSegment(triangle.pos[1], triangle.pos[0], out t0, ref s1);
var b = plane.IntersectSegment(triangle.pos[1], triangle.pos[2], out t1, ref s0);
ExploderUtils.Assert(a && b, "!!!!!!!!!!!!!");
// left side ... 2 triangles
var s0Left = AddIntersectionPoint(s0, triangle, triangle.ids[1], triangle.ids[2], cutVertCache[idxLeft], vertices[idxLeft], normals[idxLeft], uvs[idxLeft], tangents[idxLeft], vertexColors[idxLeft], useMeshTangents, useVertexColors, useNormals);
var s1Left = AddIntersectionPoint(s1, triangle, triangle.ids[1], triangle.ids[0], cutVertCache[idxLeft], vertices[idxLeft], normals[idxLeft], uvs[idxLeft], tangents[idxLeft], vertexColors[idxLeft], useMeshTangents, useVertexColors, useNormals);
var v0Left = AddTrianglePoint(triangle.pos[0], triangle.normal[0], triangle.uvs[0], triangle.tangents[0], triangle.colors[0], triangle.ids[0], triCache, cornerVertCache[idxLeft], vertices[idxLeft], normals[idxLeft], uvs[idxLeft], tangents[idxLeft], vertexColors[idxLeft], useMeshTangents, useVertexColors, useNormals);
var v2Left = AddTrianglePoint(triangle.pos[2], triangle.normal[2], triangle.uvs[2], triangle.tangents[2], triangle.colors[2], triangle.ids[2], triCache, cornerVertCache[idxLeft], vertices[idxLeft], normals[idxLeft], uvs[idxLeft], tangents[idxLeft], vertexColors[idxLeft], useMeshTangents, useVertexColors, useNormals);
// Triangle (v2, s1, s0)
triangles[idxLeft].Add(v2Left);
triangles[idxLeft].Add(s1Left);
triangles[idxLeft].Add(s0Left);
// Triangle (v2, v0, s1)
triangles[idxLeft].Add(v2Left);
triangles[idxLeft].Add(v0Left);
triangles[idxLeft].Add(s1Left);
// right side ... 1 triangle
var s0Right = AddIntersectionPoint(s0, triangle, triangle.ids[1], triangle.ids[2], cutVertCache[idxRight], vertices[idxRight], normals[idxRight], uvs[idxRight], tangents[idxRight], vertexColors[idxRight], useMeshTangents, useVertexColors, useNormals);
var s1Right = AddIntersectionPoint(s1, triangle, triangle.ids[1], triangle.ids[0], cutVertCache[idxRight], vertices[idxRight], normals[idxRight], uvs[idxRight], tangents[idxRight], vertexColors[idxRight], useMeshTangents, useVertexColors, useNormals);
var v1Right = AddTrianglePoint(triangle.pos[1], triangle.normal[1], triangle.uvs[1], triangle.tangents[1], triangle.colors[1], triangle.ids[1], triCache, cornerVertCache[idxRight], vertices[idxRight], normals[idxRight], uvs[idxRight], tangents[idxRight], vertexColors[idxRight], useMeshTangents, useVertexColors, useNormals);
// Triangle (s0, s1, v1)
triangles[idxRight].Add(s0Right);
triangles[idxRight].Add(s1Right);
triangles[idxRight].Add(v1Right);
// buffer intersection vertices for triangulation
if (triangulateHoles)
{
if (idxLeft == 0)
{
contour.AddTriangle(cutTri, s0Left, s1Left, s0, s1);
}
else
{
contour.AddTriangle(cutTri, s0Right, s1Right, s0, s1);
}
}
}
else
{
var a = plane.IntersectSegment(triangle.pos[0], triangle.pos[1], out t0, ref s0);
var b = plane.IntersectSegment(triangle.pos[0], triangle.pos[2], out t1, ref s1);
ExploderUtils.Assert(a && b, "!!!!!!!!!!!!!");
// right side ... 2 triangles
var s0Right = AddIntersectionPoint(s0, triangle, triangle.ids[0], triangle.ids[1], cutVertCache[idxRight], vertices[idxRight], normals[idxRight], uvs[idxRight], tangents[idxRight], vertexColors[idxRight], useMeshTangents, useVertexColors, useNormals);
var s1Right = AddIntersectionPoint(s1, triangle, triangle.ids[0], triangle.ids[2], cutVertCache[idxRight], vertices[idxRight], normals[idxRight], uvs[idxRight], tangents[idxRight], vertexColors[idxRight], useMeshTangents, useVertexColors, useNormals);
var v1Right = AddTrianglePoint(triangle.pos[1], triangle.normal[1], triangle.uvs[1], triangle.tangents[1], triangle.colors[1], triangle.ids[1], triCache, cornerVertCache[idxRight], vertices[idxRight], normals[idxRight], uvs[idxRight], tangents[idxRight], vertexColors[idxRight], useMeshTangents, useVertexColors, useNormals);
var v2Right = AddTrianglePoint(triangle.pos[2], triangle.normal[2], triangle.uvs[2], triangle.tangents[2], triangle.colors[2], triangle.ids[2], triCache, cornerVertCache[idxRight], vertices[idxRight], normals[idxRight], uvs[idxRight], tangents[idxRight], vertexColors[idxRight], useMeshTangents, useVertexColors, useNormals);
// Triangle (v2, s1, v1)
triangles[idxRight].Add(v2Right);
triangles[idxRight].Add(s1Right);
triangles[idxRight].Add(v1Right);
// Triangle (s1, s0, v1)
triangles[idxRight].Add(s1Right);
triangles[idxRight].Add(s0Right);
triangles[idxRight].Add(v1Right);
// left side ... 1 triangle
var s0Left = AddIntersectionPoint(s0, triangle, triangle.ids[0], triangle.ids[1], cutVertCache[idxLeft], vertices[idxLeft], normals[idxLeft], uvs[idxLeft], tangents[idxLeft], vertexColors[idxLeft], useMeshTangents, useVertexColors, useNormals);
var s1Left = AddIntersectionPoint(s1, triangle, triangle.ids[0], triangle.ids[2], cutVertCache[idxLeft], vertices[idxLeft], normals[idxLeft], uvs[idxLeft], tangents[idxLeft], vertexColors[idxLeft], useMeshTangents, useVertexColors, useNormals);
var v0Left = AddTrianglePoint(triangle.pos[0], triangle.normal[0], triangle.uvs[0], triangle.tangents[0], triangle.colors[0], triangle.ids[0], triCache, cornerVertCache[idxLeft], vertices[idxLeft], normals[idxLeft], uvs[idxLeft], tangents[idxLeft], vertexColors[idxLeft], useMeshTangents, useVertexColors, useNormals);
// Triangle (s1, v0, s0)
triangles[idxLeft].Add(s1Left);
triangles[idxLeft].Add(v0Left);
triangles[idxLeft].Add(s0Left);
// buffer intersection vertices for triangulation
if (triangulateHoles)
{
if (idxLeft == 0)
{
contour.AddTriangle(cutTri, s0Left, s1Left, s0, s1);
}
else
{
contour.AddTriangle(cutTri, s0Right, s1Right, s0, s1);
}
}
}
}
#if PROFILING
MeasureIt.End("CutCycleSecondPass");
#endif
if (triangulateHoles)
{
#if PROFILING
MeasureIt.Begin("FindContours");
#endif
contour.FindContours();
if (contour.contour.Count == 0 || contour.contour[0].Count < 3)
{
if (allowOpenMesh)
{
triangulateHoles = false;
}
else
{
stopWatch.Stop();
return stopWatch.ElapsedMilliseconds;
}
}
#if PROFILING
MeasureIt.End("FindContours");
#endif
}
List<int>[] trianglesCut = null;
if (triangulateHoles)
{
#if PROFILING
MeasureIt.Begin("Triangulate");
#endif
trianglesCut = new List<int>[2]
{new List<int>(contour.MidPointsCount), new List<int>(contour.MidPointsCount)};
Triangulate(contour.contour, plane, vertices, normals, uvs, tangents, vertexColors, trianglesCut, true,
useMeshTangents, useVertexColors, useNormals);
#if PROFILING
MeasureIt.End("Triangulate");
#endif
}
if (vertices[0].Count > 3 && vertices[1].Count > 3)
{
#if PROFILING
MeasureIt.Begin("CutEndCopyBack");
#endif
mesh0.mesh = new Mesh();
mesh1.mesh = new Mesh();
var verticesArray0 = vertices[0].ToArray();
var verticesArray1 = vertices[1].ToArray();
mesh0.mesh.vertices = verticesArray0;
mesh0.mesh.uv = uvs[0].ToArray();
mesh1.mesh.vertices = verticesArray1;
mesh1.mesh.uv = uvs[1].ToArray();
if (useNormals)
{
mesh0.mesh.normals = normals[0].ToArray();
mesh1.mesh.normals = normals[1].ToArray();
}
if (useMeshTangents)
{
mesh0.mesh.tangents = tangents[0].ToArray();
mesh1.mesh.tangents = tangents[1].ToArray();
}
if (useVertexColors)
{
mesh0.mesh.colors32 = vertexColors[0].ToArray();
mesh1.mesh.colors32 = vertexColors[1].ToArray();
}
if (trianglesCut != null && trianglesCut[0].Count > 3)
{
triangles[0].AddRange(trianglesCut[0]);
triangles[1].AddRange(trianglesCut[1]);
}
mesh0.mesh.triangles = triangles[0].ToArray();
mesh1.mesh.triangles = triangles[1].ToArray();
if (!triangulateHoles)
{
// don't triangulate holes means the mesh is a 2d plane
// it is better to recalculate centroid to get precise center not just an approximation
mesh0.centroid = Vector3.zero;
mesh1.centroid = Vector3.zero;
foreach (var p in vertices[0])
{
mesh0.centroid += p;
}
mesh0.centroid /= vertices[0].Count;
foreach (var p in vertices[1])
{
mesh1.centroid += p;
}
mesh1.centroid /= vertices[1].Count;
}
#if PROFILING
MeasureIt.End("CutEndCopyBack");
#endif
meshes = new List<CutterMesh> { mesh0, mesh1 };
stopWatch.Stop();
return stopWatch.ElapsedMilliseconds;
}
stopWatch.Stop();
// UnityEngine.Debug.Log("Empty cut! " + vertices[0].Count + " " + vertices[1].Count);
return stopWatch.ElapsedMilliseconds;
}
