But my goal is not to export the rendering result to a 2d image file. I’m trying to get brain vessels in 3d. I think the most convenient way is to use “Scalar Opacity Mapping” under the “Volume Rendering” tool. A wonderful vascular tree information can be extracted. However, I want to assign this manuel rendering result to a 3d variable (or a node variable, 3d dijital matrix variable) and use it within the program.