/// <summary>
/// does not drop unused vertices.
/// </summary>
public static Mesh CutMeshGeneric2(this Mesh mesh, IsGoodHandler IsGoodFunc)
{
List <int> indexList = new List <int>(mesh.vertexCount);
for (int i = 0; i < indexList.Count; ++i)
{
indexList[i] = i; // create linear list
}
// add only triangles on the right side.
var newTriangleList = new List <int>(mesh.triangles.Length);
for (var i = 0; i < mesh.triangles.Length; i += 3)
{
bool IsGood(int _i)
{
var t = mesh.triangles[_i];
return(IsGoodFunc(mesh.vertices[t]));
}
if (IsGood(i) && IsGood(i + 1) && IsGood(i + 2))
{
//Log.Debug($"Adding triangle[i:i+2]i={i}");
newTriangleList.Add(mesh.triangles[i]);
newTriangleList.Add(mesh.triangles[i + 1]);
newTriangleList.Add(mesh.triangles[i + 2]);
}
}
var newMesh = new Mesh {
name = mesh.name + "_CutMeshGeneric"
};
newMesh.bounds = mesh.bounds;
newMesh.vertices = mesh.vertices.ToArray();
newMesh.uv = mesh.uv.ToArray();
newMesh.normals = mesh.normals.ToArray();
newMesh.tangents = mesh.tangents.ToArray();
newMesh.triangles = newTriangleList.ToArray(); // triangle must be added after vertices.
return(newMesh);
}
public static Mesh CutMeshGeneric(this Mesh mesh, IsGoodHandler IsGoodFunc)
{
const int EMPTY = -2;
#region Calculate triangles and indexes
var indexArray = new int[mesh.vertexCount];
for (int i = 0; i < indexArray.Length; ++i)
{
bool good = IsGoodFunc(mesh.vertices[i]);
indexArray[i] = good ? i : EMPTY /*mark for removal*/;
}
indexArray = indexArray.Where(v => v != EMPTY).ToArray();
// create inverse array
int[] indexArrayInverse = new int[mesh.vertexCount];
for (int i = 0; i < indexArrayInverse.Length; ++i)
{
indexArrayInverse[i] = EMPTY;
}
// switch value and index.
for (int i = 0; i < indexArray.Length; ++i)
{
indexArrayInverse[indexArray[i]] = i;
}
// update triangle indeces and add only if all their vertices is on the right side.
var newTriangleList = new List <int>(mesh.triangles.Length);
for (var i = 0; i < mesh.triangles.Length; i += 3)
{
int newTriangle0 = indexArrayInverse[mesh.triangles[i]];
int newTriangle1 = indexArrayInverse[mesh.triangles[i + 1]];
int newTriangle2 = indexArrayInverse[mesh.triangles[i + 2]];
if (newTriangle0 != EMPTY && newTriangle1 != EMPTY && newTriangle2 != EMPTY)
{
newTriangleList.Add(newTriangle0);
newTriangleList.Add(newTriangle1);
newTriangleList.Add(newTriangle2);
}
}
#endregion
var newVertices = new Vector3[indexArray.Length];
var newUV = new Vector2[indexArray.Length];
var newNormals = new Vector3[indexArray.Length];
var newTangents = new Vector4[indexArray.Length];
for (int i = 0; i < indexArray.Length; ++i)
{
int j = indexArray[i];
newVertices[i] = mesh.vertices[j];
newUV[i] = mesh.uv[i];
newNormals[i] = mesh.normals[j];
newTangents[i] = mesh.tangents[j];
}
var newMesh = new Mesh();
newMesh.bounds = mesh.bounds;
newMesh.vertices = newVertices;
newMesh.normals = newNormals;
newMesh.tangents = newTangents;
newMesh.triangles = newTriangleList.ToArray(); // triangle must be added after vertices.
return(newMesh);
}
