Lighting & Rendering: Ray Depth

This task explores ‘ray depth’ and how it effects the rendering process. Ray Depth allows you to configure settings that limit the ray recursion based on ray type. Higher values will increase render time.

Render 1 (Before)

The first render shows how the materials in the scene have light manipulating characteristics, as both the glass and liquid refract light. However, the render shows some issues. For example, the glass behind isn’t seen through the liquid of the glass in front, which would be expected; this is being blocked by a limited ray depth.

Ray depth can be adjusted in ‘Arnold Render Settings’, which consists of multiple sliders:

Total – total of all sliders, a cut-off point. This must be increased if we increase any other sliders.

Diffuse – light bouncing around our scene (indirect light). The higher the value, the more light that bounces around the scene.

Specular – changes highlighting, but is also a reflectivity channel.

Transmission – works with the transparency of shaders.

Volume – atmosphere or fluid effects. Renders fog etc. more effectively.

Transparency depth – rendering through multiple transparent materials. 

Render 2 (After)

The second render shows the fix that was made, as we can now see the background glass through the liquid of the foreground glass. This has been achieved by increasing the ‘transmission’ to 12; there are a total of twelve surfaces in the scene (4 for each glass making 8 + both sides of each liquid, making 12).