A method for generating palettized images for use in determining effects of direct lighting for a computer graphic, i.e., CG, representation of a material by a material building system, the method comprising: obtaining a plurality of first mirror images, wherein each first mirror image includes a plurality of reflected images of a first sample of the material reflected by a corresponding mirror of a plurality of mirrors, wherein the plurality of first mirror images include images taken while the light source is directly illuminating different mirrors of the plurality of mirrors, wherein each first mirror image includes a plurality of regions, wherein each region corresponds to an area including a reflected image of the first sample that includes a reflection at a respective mirror of a plurality of mirrors, and wherein planar reflective surfaces of the plurality of mirrors approximate a portion of an outer surface of an ellipsoid, wherein a center of the first sample is positioned at a first focal point of the ellipse, and wherein the plurality of first mirror images are produced by applying a color transformation based on generated color calibration data by the material building system; for each first image of the plurality of first mirror images: generating a respective region image for each region in the first image by using the color calibration data, wherein the respective region image is generated by extracting the reflected image corresponding to the region from the first image, wherein each region image comprises a respective plurality of region image pixels, and palettizing each of the region images, wherein palettizing each of the region images reduces the number of colors used in each of the region images to a predetermined number of colors; and providing each palettized image to a CG rendering engine for use in determining effects of direct lighting when shading the CG representation of the material. obtaining a plurality of first mirror images, wherein each first mirror image includes a plurality of reflected images of a first sample of the material reflected by a corresponding mirror of a plurality of mirrors, wherein the plurality of first mirror images include images taken while the light source is directly illuminating different mirrors of the plurality of mirrors, wherein each first mirror image includes a plurality of regions, wherein each region corresponds to an area including a reflected image of the first sample that includes a reflection at a respective mirror of a plurality of mirrors, and wherein planar reflective surfaces of the plurality of mirrors approximate a portion of an outer surface of an ellipsoid, wherein a center of the first sample is positioned at a first focal point of the ellipse, and wherein the plurality of first mirror images are produced by applying a color transformation based on generated color calibration data by the material building system; for each first image of the plurality of first mirror images: generating a respective region image for each region in the first image by using the color calibration data, wherein the respective region image is generated by extracting the reflected image corresponding to the region from the first image, wherein each region image comprises a respective plurality of region image pixels, and palettizing each of the region images, wherein palettizing each of the region images reduces the number of colors used in each of the region images to a predetermined number of colors; and generating a respective region image for each region in the first image by using the color calibration data, wherein the respective region image is generated by extracting the reflected image corresponding to the region from the first image, wherein each region image comprises a respective plurality of region image pixels, and palettizing each of the region images, wherein palettizing each of the region images reduces the number of colors used in each of the region images to a predetermined number of colors; and providing each palettized image to a CG rendering engine for use in determining effects of direct lighting when shading the CG representation of the material.