Summary

In this chapter, we introduced the variable rate shading technique. We gave a brief overview of this approach and how it can be used to improve the performance of some rendering passes without a loss in perceived quality. We also explained the edge detection algorithm used to determine the shading rate for each fragment.

In the next section, we illustrated the changes necessary to enable and use this feature with the Vulkan API. We detailed the options available to change the shading rate at the draw, primitive, and render pass level. We then explained the implementation of the edge detection algorithm using a compute shader and how the result is used to generate the shading rate image.

In the last section, we introduced specialization constants, a mechanism provided by the Vulkan API to modify shader constant values at compile time. We illustrated how this feature can be used to control the group size of compute shaders for optimal performance based on the device our...