Solved by AlexanderB in post #3 
              
              
                Thank you for your reply. Seems like grid_sampler_2d is more like a low-level function, not to be used by “normal” users. I use grid_sample now and it works as expected: 
namespace F = torch::nn::functional; 
F::grid_sample(img1_t, map_t, F::GridSampleFuncOptions() 
.mode(torch::kBilinear) 
.padding…