Integration: Active Volumes Part 1

It never clicked for me until recently I learned that clouds should have movement in film. Cloud movement is apparent when outside in nature, but after I learned at work that clouds should have subtle movement in a shots, it all made sense. So how much should clouds move in a scene, and how do they make god rays twinkle?

Cloud/fog movement ca be subtle and not fast enough to call attention to itself. Playing this shot in a ping pong loop in actual speed, there is nothing really standing out about the cloud movement until sped up.

The clip above also include clouds casting shadows. Another one of the most surprising nuggets of wisdom that blew my mind at work is that moving clouds results in moving cloud shadows. It seems obvious, but I realized how much scenes can benefit from cloud shadow movement just as subtle as their cloud movements. Below is an example in real time.

Sped up

Now for god rays. Strong haze paired with moving clouds results in god rays that twinkle. This is sped up, but god rays in realtime should have slight movement.

Twinkling god rays can be found screen right in this shot from Return of the King.