This application relates to determining uniformity of a housing for a computing device based on characteristics of a reflected pattern of light incident upon the housing. The reflected pattern of light can include an array of shapes such as dots whose orientation and location can provide indications of uniformity for the housing. The array of shapes are analyzed to determine certain geometric properties such as area for each shape in the array of shapes. The geometric properties can thereafter be compared to a predetermined geometric, threshold, or tolerance value, and each shape can be assigned a rank of uniformity. Once a rank of uniformity is defined for each shape, a compilation of uniformity values can be generated and used to find portions on the housing where the housing is not uniform or flat.