How do I get extents in my mesh

Question

I am creating a AABB for collision detection. I need to calculate the extents for my model and also update them when my model moves. I calculate my min and max when I create my mesh and I use my position to reference the center.

Could someone please show me how to get the extents either with my min and max vectors or with an array of vertices.

Actually for more clarification I tried this

public Vector3f getMin() {
    return Vector3f.sub(pos, extents, null);
}

public Vector3f getMax() {
    return Vector3f.add(pos, extents, null);
}

The problem is that everything seems to be centered around the origin(0,0,0). The position is the position of the entity the AABB represents.

Answer 1

The size of the box that covers the whole mesh is simply the difference between the max and the min position: vec3 size = max - min;.

Now from that you can get the extents simply by halfing the size: vec3 extents = size * 0.5f;