Help Obi rope in combination with joints stretches the rope infinitely

[josemendez]

Since I have a moveable object connected to the rope, I added the option to throw the object by adding a force to the rigidbody. When throwing the object without the rope connection, it normally flies off. When throwing the object connected to the rope, it looks as though it flies off, but it quickly gets pulled back by the rope forces, resulting in it not going anywhere. Is there a way to lessen the internal forces of the rope in order to have the connected object fly off normally? I tried playing around with the distance constraints, but without luck.

Hi, (sorry I didn't see this question earlier!)

You can change the "strength" of a given constraint type globally per solver, this is the "relaxation" factor for each constraint in the solver's constraints foldout. See the very end of: http://obi.virtualmethodstudio.com/manua...olver.html

Note this is literally a global multiplier on constraint force: if you set it to 0.25 for distance constraints, all constraints will be multiplied by 0.25 so they will do 25% of the work they'd normally do each frame. This should only be used as a quick way to change the behavior of all constraints in the solver, as it isn't physically correct: it does not have things like the amount of time passed since last frame or relative object mass into account.

A generally better way to change constraint strength is to set their compliance. This can also be changed on a per-rope basis. Compliance is the inverse of stiffness, more compliant constraints are "softer". Try setting your rope's distance constraint compliance to a small non-zero value like 0.02, that will make the rope more elastic, fully taking timestep and masses into account.