25-02-2021, 10:02 AM
(This post was last modified: 25-02-2021, 10:08 AM by josemendez.)
Hi there! 
Doesn't really make much sense to freeze position/orientation on a softbody, since they don't have a "position" or "orientation". You can't determine the location of a softbody using a rigid transform: what would it mean for a softbody to "be at" <2,3,0>? what if it's stretched, does that change its position? or scale? maybe both? imagine a long, thin rod: if you tie it into a knot, has it rotated? how much? around what axis? These questions only make sense for rigid objects.
You can only reason in terms of position/rotation/scale if an object is rigid. In Obi, only individual particles are rigid. For entire softbodies, the closest thing to a "position" you have is the position of their center of mass. You could also use a matrix to express the optimal rotation and scale from the rest shape to the deformed shape, but that's not quite what we normally refer to as rotation/scale.
This being said, you can work with individual particles and constrain their linear/angular velocities to lie on a specific plane or axis. See:
http://obi.virtualmethodstudio.com/tutor...icles.html
Doesn't really make much sense to freeze position/orientation on a softbody, since they don't have a "position" or "orientation". You can't determine the location of a softbody using a rigid transform: what would it mean for a softbody to "be at" <2,3,0>? what if it's stretched, does that change its position? or scale? maybe both? imagine a long, thin rod: if you tie it into a knot, has it rotated? how much? around what axis? These questions only make sense for rigid objects.
You can only reason in terms of position/rotation/scale if an object is rigid. In Obi, only individual particles are rigid. For entire softbodies, the closest thing to a "position" you have is the position of their center of mass. You could also use a matrix to express the optimal rotation and scale from the rest shape to the deformed shape, but that's not quite what we normally refer to as rotation/scale.
This being said, you can work with individual particles and constrain their linear/angular velocities to lie on a specific plane or axis. See:
http://obi.virtualmethodstudio.com/tutor...icles.html