Weird teapot geometry

[lfrati]

Isn't there something funny going on with the teapot?
The handle and the spout don't quite seem on opposite sides of it.

This is what it should look like, right?

I think it is particularly noticeable in the term version where without the shadows

[fixxi]

I was wondering the same thing.

[fixxi]

Ok, this was a fun way to learn about projection and perspective.

Dividing x, y component by z is a simple way to get the illusion of perspective (things farther away look smaller). The reason this effect is much more pronounced in this example is the shape of the object (spout and handle on opposite sites with large |z|) and the spinning motion.

Divide by z/2 or remove the division completely to see what is going on.

olive.c/demos/model3d.c

Lines 45 to 50 in 2e20ec1

	static Vector2 project_3d_2d(Vector3 v3)
	{
	if (v3.z < 0) v3.z = -v3.z;
	if (v3.z < EPSILON) v3.z += EPSILON;
	return make_vector2(v3.x/v3.z, v3.y/v3.z);
	}