How to make "god rays" with Corona for Cinema 4D? – Chaos Help Center

Cliff model by 3dhdscan, under Creative Commons Attribution 4.0 International (CC BY 4.0) license.

Crepuscular rays or "god rays" as they're more commonly referred to are indeed possible with Corona. God rays are an atmospheric optical effect that happens when light penetrates through gaps in clouds or other objects. The effect of these columns is caused by sunlit air (or moisture) against a darker environment or background.

A real-world example can be seen below:

Image credit: Bengamin Jerrems

We can recreate this effect in Corona using:

1. The volume material applied to a cube in front of the camera:

Note: For this to work, It is very important that the camera remains outside or does not intersect with the cube or any other object that the volume material may be applied to. As shown below:

2. The Global Volume channel found in Render Settings > Scene Environment > Volume:

In our example, a bright light source is needed. For this we have used a Corona sun and sky object. Lowering your sun's altitude and having it's directionality pointing towards your camera will enhance the god ray effect. Changes to your Corona sky will also be automatic as it's synchronized with Corona's sun object.

Volume Material

Our volume material has a distance set to 5000cm. The greater the value the more light will penetrate the "atmosphere" or object, a lower value will result in a much more dense look. Similar to that of cumulus clouds in the example below.

Click on the image to see the comparison:

Single bounce (direct lighting) was also enabled in the volume material for our god ray scene. This eliminates light rays from bouncing (scattering) more than once after passing through the volume material. The result is darker and may produce a less realistic effect but it will speed up your render times greatly.

Material settings: