1. A computer-implemented method of managing secondary rays in a ray-tracing process, the computer-implemented method comprising: defining and constructing a unidirectional ray tracing object, wherein the unidirectional ray tracing object prevents secondary tracing rays from emanating from a user-selected virtual object in a computer generated illustration; logically surrounding the user-selected virtual object with the unidirectional ray tracing object; generating a tree graph of multiple virtual objects in the computer-generated illustration; in response to detecting another virtual object in the computer generated illustration that has a same shape as the user-selected virtual object, automatically applying the unidirectional ray tracing object to said another virtual object, wherein said automatically applying applies the unidirectional ray tracing object only to virtual objects that are depicted as leaf nodes on the tree graph, and wherein the leaf nodes represent purely reflective virtual objects whose secondary tracing rays align exactly with primary tracing rays that strike the purely reflective virtual objects; and ray tracing virtual secondary rays in the computer generated illustration, wherein the unidirectional ray tracing object prevents secondary rays from emanating from the user-selected virtual object.