Get label coordinates from paint filter

Hello everyone,

I’m using paint filter like in the example; vtk.js
How we can get pixel coordinates of the labels?

i will be appreciated for your help.

You can iterate over the pixel arrays to figure out which ones are set.

let data = labelImageData.getPointData().getScalars().getData().
let coords = [];
let xyArea = xDim*yDim
for (let i = 0; i < data.length; i++) {
  if (data[i] === 0) continue; // not painted
  let z = Math.floor(i / xyArea);
  let y = Math.floor(i / xDim) % yDim;
  let x = i % xDim;

How do I know, which coordinates belong to which label?

Based on the value of data[i]. Each label is a unique non-zero value.

Thank you!