An unbiased render engine is becoming very popular among 3D artists these days, but a lot of users still get confused by the way those render engines work. Before we go any further, let's take a look at how this render works to avoid any surprises. Almost all render engines today work with the so-called render threads. Render threads are small squares that render and generate the images for each sector of the image. This is the way in which almost all renderers, including the internal renderers of 3D suites such as Blender, work.
With the unbiased render engines, we will have a very different process, which uses what is called a progressive refinement of the images. By the time you hit the Render button, in a few moments, we will be able to see the full image of the scene. This image will have a very poor quality and a lot of noise, as shown in the following screenshot:
This is just the first interaction of the renderer with the scene, and that's the...
