mrdoob/three.js — Issue #684: Are non-affine transforms handled correctly?
Author: dimituri
Created: 2011-10-25 00:27:22+00:00
State: open

The non-affine transforms part of geometry matrix (n41, n42, n43) works not as expected, on geometries with low polygon count.

For example, here's two pictures of Charles Petzold's face:

![](http://i.imgur.com/PQoYl.png)
1. With piecewise affine transform
2. With actual non-affine transform

The first one is what we would get with one Face4 (two triangles, right?). The second one is the result of adding much more faces. The thing is, it should be possible to do the second one even with two faces.

So my question is: why are non-affine transforms approximated with piecewise affine transforms? Is there a way to do a pretty non-affine transform on something like `THREE.PlaneGeometry(1, 1, 1, 1)`?