# Curve Based Image Sampler

Hello,

I’m trying to make a curve-based image “sampler”. I have imported an image texture on a subdivided plane and baked vertex colors as “pixels”. My current debug view is to render the verts as shadless points in cycles.

I would like to instance individual curves on each pixel row, whose curve factor/width would be controlled by the points’ stored color attribute. I’ve been able to resample the indices in a way that mimics a rasterizer, going across the x coordinate, then down to the next row and so on. I figured this will be needed for defining those individual rows and keeping things in order.

Where I’m stuck is generating that curve set, one curve for each row, and sampling the respective color data. I keep running into issues with Sample Index (sample vector at indices greater than…not getting the right results in the spreadsheet/ viewer). Which is primarily because of a novice understanding but will need direction anyhow.

Would appreciate any pointers.

Best and Thanks
Dhumpo

No need to sample. You can convert the points to curves directly and just keep all the attributes (see the spreadsheet):

Just make the UV’s y-coord the Group ID to the Points to Curves node (and the UV’s x-coord the weight)… Here I’m subdividing a plane and using the fact that each row will have `2^s-1` points where `s` is the subdivisions and multiplying that with the UV’s y-coord. If you’re using a grid you can just plug in the y resolution into the Multiply node instead.

Hope that helped.

2 Likes

zero,

This is awesome thank you for the quick reply. Is there more documentation on the Points to Curves node? Ill mark this as solved, but if you have the patience I have a question. The Group ID can take any integer/attribute field then? and the weight is the contents of those respective values?

Best
Dhumpo

Documentation here.

All points that share the same Group ID will be in the same spline and their order is determined by Weight… so, I abuse this node to order things also.

Good luck.

1 Like