ABSTRACT
This chapter presents a method for tracing incoherent secondary rays that integrates well with existing rasterization-based real-time rendering engines. It explores a Graphics processing units-based object-order ray-tracing algorithm that allows for the tracing of incoherent secondary rays at interactive speeds. The chapter demonstrates the tracing of incoherent secondary rays with reflection rays. The more expensive ray tracing can easily be restricted to complex phenomena that require it, such as reflections and refractions on arbitrarily shaped scene geometry. Ray tracing is a robust and flexible approach to image synthesis that elegantly solves many problems that are hard to solve using rasterization. The ability to determine intersections with the scene geometry for arbitrary rays therefore allows for a trivial implementation of many light transport phenomena. In contrast, efficient ray tracing techniques typically depend on pre-built spatial acceleration data structures that allow for fast random access to the scene geometry.
