How to sample a custom index with Set Position Sequential 3D?

[techtonicplates]

So I’m using Set Position Sequential ThreeDimensional to set positions but the index doesn’t match up with the sequential index of how the render texture is being read. So how do I then convert the index to correct uv coords to sample the texture instead? I thought it might work if I switch the x and y around but doesn’t seem to do the trick. Thanks in advance!

[techtonicplates]

I figured out the UV values:

V = id / width * height```