internal virtual void Rotate(double angle, Vector3D direction)
{
Vector3D d = direction.Unit();
double x = d.X;
double y = d.Y;
double z = d.Z;
TransformationMatrix m = new TransformationMatrix();
double c = Math.Cos(angle);
double s = Math.Sin(angle);
m[0,0] = (x*x) * (1-c)+c;
m[1,0] = x*y * (1-c)-z*s;
m[2,0] = x*z * (1-c)+y*s;
m[0,1] = y*x * (1-c)+z*s;
m[1,1] = (y*y) * (1-c)+c;
m[2,1] = y*z * (1-c)-x*s;
m[0,2] = x*z * (1-c)-y*s;
m[1,2] = y*z * (1-c)+x*s;
m[2,2] = (z*z) * (1-c)+c;
UpdateLocation(m);
m = m.Invert().Transpose();
foreach (Vector3D v in m_Mesh.Normals)
{
double x0 = m[0, 0] * v.X + m[0, 1] * v.Y + m[0, 2] * v.Z + m[0, 3];
double y0 = m[1, 0] * v.X + m[1, 1] * v.Y + m[1, 2] * v.Z + m[1, 3];
double z0 = m[2, 0] * v.X + m[2, 1] * v.Y + m[2, 2] * v.Z + m[2, 3];
v.X = x0; v.Y = y0; v.Z = z0;
}
}
