An intersection of a cut plane with a proxy geometry representing a scan volume is determined with a processor. The intersection is simplified, such as identifying a quadrilateral or triangle most closely enclosing the intersection. The vertex processor of a GPU deforms a reference grid and determines Cartesian coordinates and the texture coordinates for grid points of the reference grid as a function of the input intersection. The vertex processor provides coordinates for data for subsets of cut planes. The fragment processor inputs the texture coordinates and retrieves the data from the texture memory. The data is blended. The blended subsets are then blended together in the frame buffer of the GPU.