Multithreaded Paraboloid Mapping - Practical Rendering and Computation with Direct3D 11 - page 571

captured and then used to perform a per-pixel lookup to find approximately what would
be visible at each pixel on a reflective object. The technique requires these special render
targets to be filled for each reflective object in a scene, so we can use these rendering passes
as a vehicle to test our multithreaded submission system's performance by using multiple
reflective objects that are near one another. By varying the number of reflective objects, we
should be able to determine roughly what impact the multithreading features have on the
overall performance of the application.
This chapter will explore the details of the dual paraboloid environment mapping
technique, develop an implementation for it, and then execute the algorithm with and with-
out multithreading, to attempt to characterize the benefits of performing multithreading
draw submission. The chapter closes with a discussion of how this ability can be used, and
when it should be beneficial.
13.1 Theory
The basic concept behind paraboloid mapping can be approached by considering what
would be visible if you viewed a perfectly reflecting paraboloid surface. In many ways,
Figure 13.1. A plot of the paraboloid surface with the x and y parameters constrained to the [-1,1] domain.