Hi everyone, I really appreciate some help, my problem is maybe something easy but I haven't work with this kind of things yet so I don't have too much experience combining 2D with 3D vectors.

My problem is this one, I have a 3D arm which I want to follow the mouse pointer since it has a crosshair bitmap, I was trying to do so but the way I was implementing works just with 3D objects, here's the code attached to the arm model:


vec_set(temp.x, me.x);

vec_set(temp2.x, mouse_pos);

vec_sub(temp.x, temp2.x);

vec_to_angle(me.tilt, temp);


And here's an image of what I want to achieve:






I don't have anything else to add, so thanks for reading and I hope I can find some help soon.