Bullet Physics and Blender

[josvschijndel]

Hello everyone!

I am working on a project, and I am using Blender, and since it uses Bullet I landed on this forum =)
I already found on the internet it is a very good physics engine to use.

Now I have a few (short) questions:

1. I have the physical meaning of the Damping Ratio ( http://en.wikipedia.org/wiki/Damping_ratio ), but what definition does bullet use for Rotational Damping?
2. In Blender, the gravity is specified as 9.81. If I am correct, this means 1 BU/s^2 (= one Blender Unit per square second). I used 1 BU = 1 dm, so this means my gravity constant becomes 10 BU/s^2
3. The Form Factor which scales with the Moment of Inertia. Does it use the value specified in Mass for its calculation? Is there also an equation for the Form Factor like with the Damping Ratio?

I added a picture of the GUI of Blender wherein these values can be specified.
4. I'm kind of getting as much information possible about all values, so if anyone is bored, feel free to explain all values in the attached picture. Or if you have a link for that matter, I'm open to all possible information =)

Thanks in advance for your time!
Kind regards,
Jos van Schijndel.

[josvschijndel]

UP =)

[Erwin Coumans]

You can find more information about Blender - Bullet integration in this link: http://bulletphysics.org/mediawiki-1.5. ... Blender_3D

In short, the angular damping is similar to the linear damping, but it applies to the angular velocity (instead of linear velocity).
'Form factor' just scales the inertia tensor by multiplication. The inertia tensor calculation depends on the shape and mass.

I can highly recommend the book 'Bounce, Thumble and Splash' in that wiki page. Also, you can get more replies in the Blender Artists forums:
http://blenderartists.org/forum/forumdisplay.php?f=12

Thanks,
Erwin