I set up a simple scene with a sphere and two sloping planes for the sphere to roll down.
It seems to me that the physics with -9.81 setting for gravity is slow - the sphere seems to move slowly through the air when moving. I increased it to -18 and that seems more normal and realistic to me. Is there an issue or is it just me?
PhysicsMarbleWood.blend (529 KB)
You are right. I set friction=0, and even with gravity=-18 the ball seems slowly falling into the void at 24fps.
I have found with friction=0 the sphere slides instead of rolls - which makes it look odd when moving along a non icy surface.
Also, the mass doesn’t appear to impact the behavior either.
I did the test only dropping the ball in free fall without that mechanism to get a better idea of the speed. I had configured friction=0 just in case because I was not sure if there are some settings related to air friction, but apparently this does not change the result in free fall.
Here the test:
http://www.pasteall.org/blend/37752
with the following dimensions. Gravity=-9.81. Ball with approximately 1m in diameter. The ground at 100m. The ball takes around 113 frames to touch the ground. 113 frames at 24 fps would be about 4.7 sec.
I’m not good at math, but I think the time is approximately right.
Edit:
But using the mechanism, I can not find a good setup where the simulation looks real at 24fps and gravity= -9.81.