Rotating a static RBD object

[ziggx]

Hi there,

I have an RBD object sitting on a static RBD turntable - I want the turntable to rotate slowly and affect the RBD object. I thought I could simply add a Motion position sop and add rotation with an expression but it sends my RBD object flying even at a very low turn speeds. Am I just doing this wrongly or have I missed something very obvious? TIA for any helpful hints.

Best Wishes

Ziggx

[mightcouldb1]

Can you post your hip file?

[GallenWolf]

Tried stuff like this before, should work. Have tried complicated setups with moving animated geo and simulated rbds with springs and all.

Attached is a quick test.

GW

[Nibbler]

hey Ziggx, I made quick hop for you, is it something like this?

I didn't use static object, just rbd with no gravity

quick_hip_for_U.hipnc

[anim]

there is not a good idea Deforming Geometry since there is no need for it

because the Collision volume is reevaluated every timestep, which is very unefficient, slows simulation and may produce bad collision volume depending on object orientation

of course only when it's not really deforming like the box here, if it is then you probably cannot avoid this

what you just can do is

create dynamic RBD Objects from both (just shelf tool)

but in the "static" uncheck Create Active Object, making it static

then append Motion DOP, with some expression on rotation and change default mode to Set Always

that should be it

depending on your objects you can also adjust collision volumes and set surface Collisions to edges if you need to

look at the example

rotating_static_RBD.hipnc

Edited May 21, 2010 by anim

[ziggx]

Aah! Now I understand. Thanks to everyone for their helpful inputs and explanations.

Best Wishes

Ziggx

there is not a good idea Deforming Geometry since there is no need for it

because the Collision volume is reevaluated every timestep, which is very unefficient, slows simulation and may produce bad collision volume depending on object orientation

of course only when it's not really deforming like the box here, if it is then you probably cannot avoid this

what you just can do is

create dynamic RBD Objects from both (just shelf tool)

but in the "static" uncheck Create Active Object, making it static

then append Motion DOP, with some expression on rotation and change default mode to Set Always

that should be it

depending on your objects you can also adjust collision volumes and set surface Collisions to edges if you need to

look at the example