3d - ThreeJS geometry flipping

Question

I am facing a problem with geometry flipping, I tried flipping using the negative scale technique but it fails.

What is the technique that I can use to flip a 3d object across specific axis?

By flipping I mean the object should look as it was rendered over a mirror.

if this is not possible through three.js rendering how can I use Blender to achieve this?

Answer 1

You have to apply a transformation matrix to the geometry (or mesh/object), here is an example for plannar (O, y, z) symetry, you can adapt for your specific case

var mS = (new THREE.Matrix4()).identity();
//set -1 to the corresponding axis
mS.elements[0] = -1;
//mS.elements[5] = -1;
mS.elements[10] = -1;

geometry.applyMatrix(mS);
//mesh.applyMatrix(mS);
//object.applyMatrix(mS);