QUOTE(ROYTERR @ 11/24/08, 08:36 PM) [snapback]295826[/snapback]
it's supoosed to fall 9.8 meters per second at 24 fps, but it doesn't, it falls a fiew cm per second, why is that?
Maya is unitless. So in fact no unit is defined in maya, sure there are residues of attempt to do so but a simulation does not actually care about units. Just coefficinets of the simulation engine matching up.*
So having 9.81 inserted is as correct as anything else. The suer just assumes one unit is one meter, as most fo mayas subsystems assume. Irrespectibly of what anybody thinks for a computer this is as valid (if not mroe so, because you know use the actual numbers used in computation and do not collude and waste time moving numbers back and forth.At least you can now get stab on the precicion) as anything else.
All maya units are assumed to be cm unless otherwise noted and no maya just does not have fully implemented units system hence the following:
QUOTE
-what should be the scene scale (cm, m,)?
one should NEVER EVER CHANGE the pref for unit for a scene, if you need some other units say one unit is XXX for yourself and model accordingly. Theres lot fo stuff in maya that breaks once you assume it just works out. It don't an most sytems assume 1cm = 1m. Or actually they assume one UNIT is cm as they have never heard of maya base unit being cm.**
- this is a interesting philosophical issue. But it seems units are so hard embedded in the way people are taught at school taht it seems they never understood anything about them and take them for face value at all times. And it is not just solved by letting a computer understand units, that just makes the error go away without fixing anything. Just making the world a bit more dangerous in the process.
Ah by the way even rocket scientists aren't impervious to this problem. Since even NASA has made the mistake computing in inches when they tought they vere doing cm.
**this is one of those things where NOTHING wasn't satisfactory for a asker i presume. (no unit is prefectky valid situation in a simulation system, just ike maths dont recognize units inside themselves they are just names for conversion factors and qute frankly convertting everything inside the sytem leads to BIG problems)