ani19tha / dynamica

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Chang Unit from centimeter to meter in Maya, Dynamica still working on centimeter unit #45

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago
1. Start Maya with centimeter unit
2. Change Unit to meter
3. Create passive plane and 1 unit w/h/d box rigid body, move to 10 unit height 
position.
4. Run sim, box is moving 100 times slower than what it should be
5. If change gravity to -981.0, it looks normal. However I am worried about 
unit used in Bullet, object mass based on density could be very wrong.

Frank

Original issue reported on code.google.com by frank.mi...@gmail.com on 6 Apr 2012 at 5:11

GoogleCodeExporter commented 9 years ago

Units should be preferably in meters indeed, for Bullet to work best. The Maya 
unit should be used to scale between Maya and Bullet (so Bullet stays in meter 
units to work best).

Bullet is not computing the mass from density, it just uses the mass as 
provided by the user. Note that large mass ratios (very heavy on very light) 
won't work well, that is why the user provides the mass. Automatic computed 
mass from density can easily lead to very large mass ratios.

Unfortunately we don't have many developers, so not sure if/when this will be 
implemented, so hopefully your workaround works for you.

Original comment by erwin.coumans on 12 Apr 2012 at 5:39