Anyone else notice the tremendous time increase when rendering volumes (clouds in my case) while an Environment light is in the scene. :shock:

It creates a beautiful result but I suppose it creates a lot of extra rays at render time.

Any tips on the various lights (like area lights ext.) while working with volumes?

No Env Light : 0:05:51
With_Env_Light : 1:18:54

It's the ray traced shadows, in particular, that bring so much of the hurt.

Many people use env lights and turn off day traced shadows on the volumes. Use a depth mapped shadow casting light instead.. Of course, you don't get the same look, but you can kinda sorta maybe get there if you squint, and use your imagination a little. :roll:

G

You can play with the CloudLight node to get that nice AO definition at the bottom of the clouds without using a Env Light. Saves a billion on render times.