Render PassesRender passes allow a rendered frame to be further broken down beyond the capabilities of Render Layers. Render Passes vary among render engines but typically they allow an image to be separated into its fundamental visual components such as diffuse, ambient, specular, etc.. extract different components of a render into separate layers, so they can be used for compositing.
Render Passes can be accessed from the Render Toolbar > Render Passes button.
Select Viewport Render Pass - This button allows you to select which Render Pass is displayed in the viewport. The render must be in progress or paused.
This section will cover the following topics: