ExtrudeGeometry can't be correctlly processed by csg

[magicmayu]

  const path = new THREE.Path()
  path.add(new THREE.LineCurve3(new THREE.Vector3(0, 0, 0), new THREE.Vector3(200, 0, 350)))
  
  const shape = new THREE.Shape();
  shape.moveTo(-50, 50);
  shape.lineTo(-50, -50);
  shape.lineTo(50, -50);
  shape.lineTo(50, 50);
  shape.lineTo(-50, 50);

  const shape2 = new THREE.Shape();
  shape2.moveTo(-55, 55);
  shape2.lineTo(-55, -55);
  shape2.lineTo(55, -55);
  shape2.lineTo(55, 55);
  shape2.lineTo(-55, 55);

  const extrudeSettings = {
    depth: 100,
    extrudePath: path,
  }
  const geometry = new THREE.ExtrudeGeometry(shape, extrudeSettings);
  const geometry2 = new THREE.ExtrudeGeometry(shape2, extrudeSettings);

  const csg1 = ThreeCSG.fromGeometry(geometry);
  const csg2 = ThreeCSG.fromGeometry(geometry2);
  const csg = csg2.subtract(csg1);

  const material = new THREE.MeshPhongMaterial({
    color: 0x999999,
  });

  const mesh = new THREE.Mesh(ThreeCSG.toGeometry(csg), material);
  scene.add(mesh)

I want to use extrudeGeometry and ThreeCSG to make tunnel. So I made two shape, one is bigger than the other. And I extrude them with a single path. After that i subtract the smaller geometry from the bigger one.
But the result is not correct.

If i change end vector of the paht to (200, 0 ,300)，the result is ok.
I don't know what happend.

[manthrax]

Yeah this looks like a numerical precision problem. To get reliable results you'll have to ensure that the 2 objects overlap with a small margin, and avoid faces in one model laying flat on faces of the other.
Sounds like you figured that out. :)
Thanks for reporting though.. let me know if there's other problems.