}
public void face(Vec3D a, Vec3D b, Vec3D c, int rgb) {
Vec3D normal = b.sub(a).crossSelf(c.sub(a)).normalize();
if (useInvertedNormals) {
normal.invert();
}
face(a, b, c, normal, rgb);
}
public void face(Vec3D a, Vec3D b, Vec3D c, Vec3D normal, int rgb) {