rendering in vtk.js compared to python rendering


Basically, I do not have a mesh vtk file, I have a flattened array of data that I want to visualize using vtk.js. I have already made the render using VTK in Python, but there are some differences in the result. In the attached screenshot you will see that the render in VTK.js will show “points” of the array with big gaps between the points of the array. The data is loaded in the same manner in python, which you can see on the right side.

The settings in python are vtkGPUVolumeRayCastMapper, mapper.setSampleDistance(0.1).

in js; mapper.setSampleDistance(0.7);

interpolation mode is nearest in both cases.

Lowering the sampledistance helps alittle, however, I do get the following warning/error when lowering the distance in vtk.js to 0.1:

vtk-28.13.0-n.js:32778 The number of steps required 4572 is larger than the
        specified maximum number of steps 1000.
        Please either change the
        volumeMapper sampleDistance or its maximum number of samples.

Why am i seeing these gaps? what can be done about it?