1. A method for blending during volume rendering with a graphics processing unit, the method comprising: determining a plurality of cut planes based on a viewing direction, the cut planes being generally parallel with each other and arranged along the viewing direction; compositing, with a fragment processor of the graphics processing unit, first and second data for first and second subsets, respectively, of the cut planes, the compositing providing composited first and second data, each of the composited first data and the composited second data being a combination or selection of data for multiple cut planes of the respective first and second subsets, the combination or selecting reducing an amount of data, the composited first data representing pixel locations of a single image and the composited second data representing the same pixel locations of the single image but at different depths relative to the viewing direction; and compositing the composited first data with the composited second data by combination or selection to form the single image representing the pixel locations for the viewing direction.