/// <summary>
/// Reverse face orientation on a subset of triangles
/// </summary>
public void ReverseTriangles(IEnumerable <int> triangles, bool bFlipVtxNormals = true)
{
if (bFlipVtxNormals == false)
{
foreach (int tid in triangles)
{
Mesh.ReverseTriOrientation(tid);
}
}
else
{
BitArray donev = new BitArray(Mesh.MaxVertexID);
foreach (int tid in triangles)
{
Mesh.ReverseTriOrientation(tid);
Index3i tri = Mesh.GetTriangle(tid);
for (int j = 0; j < 3; ++j)
{
int vid = tri[j];
if (donev[vid] == false)
{
Mesh.SetVertexNormal(vid, -Mesh.GetVertexNormal(vid));
donev[vid] = true;
}
}
}
}
}