I have two volumetric liver meshes in .vtk format (i.e. ground-truth and predicted versions) and I want to plot the error i.e., for example, the difference between the ground-truth and the predicted liver meshes on the predicted mesh / mesh coordinates with a different colour (colour code based on displacement magnitudes) to visualize how much deviation that each point has ? Is it possible in 3D slicer ? If so can you elaborate the steps with an example please ?
Does the N-th point in the first mesh correspond to the N-th point in the other mesh? If yes, then you can easily color the mesh by displacement. You can get the point positions in a numpy array, subtract them from each other, and add the resulting displacement as point scalars to the mesh. See examples in the script repository.
Alternatively, you can get a dense b-spline displacement field from the scattered points using ScatteredTransform extension, convert it to a displacement field image, and then use Probe Volume with Model module to set the displacement values into model point data.