[Pyode-user] Not-really-fixed joints

[Ethan Glasser-C. <gl...@cs...>]

Hi,

In a project I'm working on, there are objects which are "static",
which means they affect objects without objects affecting them back.
So an object can be joined using a joints to a "static" object, and
the static object will pull the other object along without changing
velocity.

I've been having a hard time figuring out how to simulate those
objects. Enclosed is my current approach. Body2 is joined, via body1,
to a static object which isn't actually in the simulation -- let's
call it "body0". Body0 moves in the negative y direction at 50 units
per second, so body1's position is forced to match body0 every tick.
After about 40 ticks, this causes my simulation to freak out and move
objects to (nan, nan, nan).

Is there a better approach to simulate this kind of thing? If not, how
can I work around this behavior? I've tried playing with CFM and ERP
parameters, both global and of the joints, but haven't found anything
useful.

Ethan