Rigid rope with heavy weight and 2 pin constraints - Printable Version +- Obi Official Forum (https://obi.virtualmethodstudio.com/forum) +-- Forum: Obi Users Category (https://obi.virtualmethodstudio.com/forum/forum-1.html) +--- Forum: Obi Rope (https://obi.virtualmethodstudio.com/forum/forum-4.html) +--- Thread: Rigid rope with heavy weight and 2 pin constraints (/thread-230.html) |
Rigid rope with heavy weight and 2 pin constraints - dignifiedweb - 13-11-2017 Hi, I was wondering for general advice on how to make the Obi Rope more rigid and less springy? I was able to add more distance constraints (300 or so) and that helped a lot, but I found I also had to take the mass down of each particle (painted to select). I got the rope to be rigid and almost no spring, but my problem is I have a pin constraint on the top particle and a pin constraint on the bottom. The bottom one is attached to a sphere collider and I have to make the sphere rigidbody's weight really light or else the springiness comes into effect in full force again with a heavier weight on it. Do you think I just have to increase the resolution? I found that resolution (amount of particles) is tough because I'm using a very tiny rope/string. Any suggestions would be much appreciated, thank you. RE: Rigid rope with heavy weight and 2 pin constraints - josemendez - 13-11-2017 (13-11-2017, 04:44 AM)dignifiedweb Wrote: Hi, This is a basic issue, common to all realtime physics engines: high mass ratios reduce convergence speed (i.e. make things stretchy and rubber like). Basic rules to avoid stretchiness: - Use tether constraints when possible. (that is, when at least 1 particle in your rope is fixed). This will ensure the rope does not exceed its rest length under any circumstance. See: http://obi.virtualmethodstudio.com/tutorials/tetherconstraints.html - If tethers are not applicable in your case, decrease the rope resolution to the minimum acceptable. (less particles=faster convergence). If needed, increase "smoothness" for better mesh rendering at low resolutions. See: http://obi.virtualmethodstudio.com/tutorials/ropeparameters.html - Increase distance and pin constraint iteration count in the ObiSolver. This decreases performance, but increases convergence speed (i.e, reduces stretchiness). - If all else fails, reduce the mass ratio: make the particles heavier, or the attached rigidbodies lighter. cheers, RE: Rigid rope with heavy weight and 2 pin constraints - dignifiedweb - 13-11-2017 (13-11-2017, 10:50 AM)josemendez Wrote: This is a basic issue, common to all realtime physics engines: high mass ratios reduce convergence speed (i.e. make things stretchy and rubber like). Basic rules to avoid stretchiness: Thank you, this helps a lot! I will report back here if I have further details to provide. I am betting the above suggestions will help me, appreciate it! |