How do I change atmosphere density?

I’m creating a level, where lots of things need to fall. But their falling speed is not scaling with their mass: if I set object’s mass to 100000kg or to 100kg, it’ll fall with the same speed. I think, the problem is, I didn’t setup a proper atmosphere in my world, and it’s density is near zero (may be even vacuum), but Google says nothing about my problem. What settings I need to setup for more realistic falling mechanics?

Hey there

The mechanics are just fine, two objects no matter what the mass/weight is, will fall at exactly the same speed to the larger gravitational object. In a perfect vacuum a feather will fall just as fast as a cannon ball. In your example, because the atmospheric density is so negligable, for a smoothly shaped object,there would be no difference between 100000kg, or 100kg.

I really don’t know a way of setting the Air density/pressure for a given height in UE4.

Hope this helps,


In a perfect vacuum a feather will fall just as fast as a cannon ball
And that’s my question: how do I give my world a proper atmosphere? As in real life the main thing, which prevents feather to fall as fast as the cannon ball is the air resistance. Because of the air, object’s mass and surface area matters.

I have a feeling you will need to implement this yourself, that is not to say there may not be a starting point though. Take a look at the hang glider in the landscape demo, that might be a good place to start.