Question

I would like to get the array of the triangles, but I can’t find it in the geometry object.

---

.faces aren’t triangles. If I create a cube, then a face looks like this:

"faces": [{
    "a": 0,
    "b": 2,
    "c": 3,
    "d": 1,
    ...

These are polygons, not faces.

Answer 1

If you push a Face4 into faces, then you’re going to end up with a quad when calling faces. If you’re pushing Face3 into faces then you’ll get a triangle back. If you’re getting a d on a faces call, you pushed a Face4.

If you’re asking how to get tris from a quad, that’s a different question.

Basically, knowing that the ‘order’ of the quad is A B C D you can generally say that A B C and A C D are triangles that will share the approximate normal of the quad. (I saw approximate because the quad may be slightly skewed. The less co-planar the points are, the more the skew will be apparent, and the more difference the normals will have.)

Now, there are other combinations that will work. The easiest way to do it is to draw out A B C D on some paper, and note the direction (Clockwise or Counterclockwise). As long as your tris are also that same direction (which ever it was) then you’ll be just fine. Clearly, if A B C is a valid tri, then so would B C A and C A B. The same goes for A C D being C D A and D A C. But you could split it across the other diagonal if you wanted as well, and form A B D and B C D. Following the previous logic you create the other identical triangles for those.