Texture with NRRDLoader


I am trying to use threejs to interact with a volumetric microscopy image showing cell nuclei. For this, I loaded a volume image X2.nrrd (1.0 MB) using this example. I changed the path to this image at this line of code, but other than that the code is the same.

The texture rendered (on the right you can see the screenshot of one of the image slices in the volume) appears to be different than the original image texture (on the left) - it looks to me to be a first-order derivative of the image intensity. (Also the rendering is flipped vertically, but that is not an issue)

Could you provide an insight regarding why the texture is rendered differently and how I could potentially fix it (right) to more closely resemble the original image (left)? Thank you very much.