Methods and systems for applying a vignette effect to a rendered computer-generated image are presented. A kernel image including a kernel shape is overlaid on a control image including a vignette shape, creating a region where the kernel shape and control image overlap. A region of the rendered image corresponding to the overlapping region is blurred based on the shape of the overlapping region. A vignetting factor indicating a loss in intensity as a result of the blurring is computed based on the area of the overlapping region and the area of the kernel shape. The intensity of the blurred region is scaled upward based on the vignetting factor. The position of the kernel image on the control shape is shifted, resulting in a new overlapping region. Blurring and intensity compensation are performed for the region of the rendered image corresponding to the new overlapping region.