Volume Conservation



This challenge was fun to find a balance between real-world physics and believable animation.

The ball has a constant volume of .857m3. It was just the standard UV sphere dropped from 10 blender units. The fall time was s=ut+1/2at^2 or 2.2 secs (high school physics). But this seemed way too long, so I put cube dude there for some perspective and the fall time was a bit more believable. The acceleration is ‘eye-balled’ from the f-curves on the graph editor. It may be fun to drop a physics driven ball next to it to see the difference.

I thought of scaling in the x-y plane to give the illusion of more speed, a bit like putting a baseball cap on backwards. However when you think about it, if anything a ball will compress in the z-axis while falling because of air pressure, even a fluid would do that. I guess it reminds the viewer of a drop elongating before it falls.

In the end, I am not sure what kind of ball this is. A cross between a beach ball at the cricket and a squash ball perhaps. Cube dude seems happy all the same.