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+--- Thread: Help Colliders for Rope or Rod (/thread-3279.html)
Colliders for Rope or Rod - heartingNinja - 16-01-2022
I am trying to create a hose for a firefighting game. Need to take it into different rooms without the rope going through the wall. It seems to work on floors. I have tried rope and rod. Adding lots of CPs in the Path editor. Using surface-based collision. It seem to work ok with close objects. One problem was wrapping it around something, like a tree. Another problem is when I get too far away from starting location the hose will often go through walls. It will go through the hall wall when I go into a room instead of sticking to the wall and following me into the room. Only will have one hose per scene and a high end PC. Any ideas on how to keep the hose from going through objects would help a lot.
Also should I use Rod or Rope? It is a VR game and physics matters, so need the hose to be stiff and heavy. Rod seems to be working better. But I am new to this asset and not sure what I should use.
Thanks
RE: Colliders for Rope or Rod - josemendez - 17-01-2022
(16-01-2022, 06:43 PM)heartingNinja Wrote: I am trying to create a hose for a firefighting game. Need to take it into different rooms without the rope going through the wall. It seems to work on floors. I have tried rope and rod. Adding lots of CPs in the Path editor. Using surface-based collision. It seem to work ok with close objects. Another problem is when I get too far away from starting location the hose will often go through walls.
Depends on how far from the starting location you are. As you get further from the work origin, floating point precision is reduced. This happens to all physics engines. Obi performs simulation in solver space, which allows you to relocate the solver position to keep floating point precision intact (this is usually referred to as a "floating origin").
(16-01-2022, 06:43 PM)heartingNinja Wrote: One problem was wrapping it around something, like a tree.
What kind of problem? wrapping around objects is no different than colliding in any other way, should be no more difficult (for instance: https://www.youtube.com/watch?v=9LXeIem4gvM)
(16-01-2022, 06:43 PM)heartingNinja Wrote: It will go through the hall wall when I go into a room instead of sticking to the wall and following me into the room. Only will have one hose per scene and a high end PC. Any ideas on how to keep the hose from going through objects would help a lot.
Collision detection is fairly robust and ropes should not go trough objects at any moment, unless they're being forced to (for instance, if they're attached to an object and that object goes into a wall). Can you share a video of this?
(16-01-2022, 06:43 PM)heartingNinja Wrote: Also should I use Rod or Rope? It is a VR game and physics matters, so need the hose to be stiff and heavy. Rod seems to be working better. But I am new to this asset and not sure what I should use.
Entirely depends on what you need! Ropes and rods simulate different real-world phenomena and behave quite differently. You can make both of them be as stiff and heavy as you want. (remember that substeps and to a lesser extent, iterations control the simulation quality and how stiff things can be: http://obi.virtualmethodstudio.com/manual/6.3/convergence.html)
There's a comparison chart between rods and ropes in the manual:
http://obi.virtualmethodstudio.com/manual/6.3/ropesetup.html
So if you need to simulate coupled torsion/bending, use rods. If you need to store a rest shape, use rods. If you don't need either of these things, or you need to cut/resize, use ropes. Ropes are slightly cheaper to simulate than rods.
kind regards,