We take a humble image and turn it into a "texture". A texture is what is "painted" onto shapes in the GL 3D world. So we have to create a world which is unsurprisingly named "jit.gl.world" and then insert a shape into it. On that shape, we project our texture (our image) and then observe the very fine results. We can rotate it in space, we can change the shape, we can change the position.
