foreach (SpriteLut lut in spriteLuts)
        {
            int spriteId = lut.atlasIndex; //  wrong?

            Color[] fullTextureFlattenedAray = textureList[spriteId].GetPixels();

            Color[] spriteAreaOnlyFlattenedArray = new Color[lut.rw * lut.ry];
            int flattenedArrayIndex = 0;

            // copy the colors from part of the index to the color map
            for (int currentx = lut.rx; currentx < lut.rx+ lut.rw; currentx++)
            {
                for (int currenty = lut.ry; currenty < lut.ry+ lut.rh; currenty++)
                {
                    spriteAreaOnlyFlattenedArray[flattenedArrayIndex] = fullTextureFlattenedAray[currentx*currenty +currentx];
                    flattenedArrayIndex++;
                }
            }

            gen.spriteCollection.spriteDefinitions[spriteId].pixelColorMap = spriteAreaOnlyFlattenedArray;
        }