public void ComputeNormal()
{
foreach (var face in this.faces)
{
face.Normal = TetMeshUtil.ComputeNormal(face);
}
Vector3D[] vn = TetMeshUtil.ComputeNormalUniformWeight(this);
foreach (var v in this.vertices)
{
v.Normal = vn[v.Index];
}
}
public static Vector3D ComputeNormal(TetFace face)
{
if (face.OnBoundary)
{
return(TetMeshUtil.ComputeNormal(face));
}
Tetrahedron selected = CheckBoundary(face);
if (selected == null)
{
return(Vector3D.Zero);
}
Vector3D[] v = new Vector3D[3];
for (int i = 0; i < 3; i++)
{
v[i] = face.Vertices[i].Pos;
}
Vector3D n = (v[1] - v[0]).Cross(v[0] - v[2]).Normalize();
foreach (var vt in selected.Vertices)
{
bool top = true;
foreach (var vf in face.Vertices)
{
if (vt == vf)
{
top = false;
break;
}
}
if (top && n.Dot(vt.Pos - v[0]) > 0)
{
n = -n;
TetVertex temp = face.Vertices[0];
face.Vertices[0] = face.Vertices[2];
face.Vertices[2] = temp;
break;
}
}
return(n);
}