Color Volume Rendering: vtkDataArray Indexing

I found my problem

I was applying *numComponents twice, once in the stride and once in the scalarIndex

this

  const yStride = dimensions[0] * numComponents;
  const zStride = dimensions[0] * dimensions[1] * numComponents;

should be

  const yStride = dimensions[0];
  const zStride = dimensions[0] * dimensions[1];

``