30-12-2021, 07:16 PM
Hi!
Just use more substeps for your updater component. Note that *zero* compliance is impossible to achieve in any realtime
iterative physics engine though. You can get arbitrarily close to zero by using more substeps/iterations. The manual contains an in-depth explanation on compliance (aka, elasticity) and substeps/iterations:
http://obi.virtualmethodstudio.com/manua...gence.html
Also keep in mind that large mass ratios will slow convergence down (again, just like in any engine).
Make sure you’re not rotating the solver when rotating the boom. Simulation takes place in solver space, so rotating the solver will rotate any actors on it and any external forces/accelerations such as gravity.
Kind regards,
(30-12-2021, 06:20 PM)rsauchuck Wrote: I am working on my crane simulator and I have 2 (related?) issues.
1. The rope I am using is still too stretchy. I want to simulate a stiff metal cable which should never stretch in length. On instantiation, or whenever i move the boom, the rope bounces the hook around like it is on a rubber band.
Just use more substeps for your updater component. Note that *zero* compliance is impossible to achieve in any realtime
iterative physics engine though. You can get arbitrarily close to zero by using more substeps/iterations. The manual contains an in-depth explanation on compliance (aka, elasticity) and substeps/iterations:
http://obi.virtualmethodstudio.com/manua...gence.html
Also keep in mind that large mass ratios will slow convergence down (again, just like in any engine).
(30-12-2021, 06:20 PM)rsauchuck Wrote: 2. When I adjust the angle of the boom, the rope and attached hook do not hang down properly. See attached screen shots. For the first screen shot, the solver was a child of the boom so I figured that what was causing the problem (the rope jutted out at the converse angle of rotation). So I moved the solver outside of the boom game object's hierarchy and attached the rope to a point on the boom (instead of to itself). That helped a little but as you can see in the second screen shot the rope is still behaving strangely. It is not straight and the hook game object isn't directly below the attachment point as it would be if gravity pulled on it
I think the second issue was because I had set the Sleep parameter for the solver too high (I was trying to make the rope less stretchy to solve issue 1) If I decrease the sleep threshold the rope does hang properly but moving the crane makes the hook flail around spastically.
How can i get a stiff rope that still hangs directly down without stretching?
Make sure you’re not rotating the solver when rotating the boom. Simulation takes place in solver space, so rotating the solver will rotate any actors on it and any external forces/accelerations such as gravity.
Kind regards,