Ropes Are Passing Through Each Other

[canerozdemir]

Hello, 

I have two ropes and they can collide with each other. However, ropes are passing through each other when one rope moves fast enough.

The rope blueprints that I used have 1000 pooled particles and 1 resolution with 0.1 thickness. Still, I have no idea how can I prevent that problem. How can I make two ropes collide with each other without passing through regardless of the speed of one?

[josemendez]

Hello, 

I have two ropes and they can collide with each other. However, ropes are passing through each other when one rope moves fast enough.

The rope blueprints that I used have 1000 pooled particles and 1 resolution with 0.1 thickness. Still, I have no idea how can I prevent that problem. How can I make two ropes collide with each other without passing through regardless of the speed of one?

Can't be prevented in all cases. This issue is called tunneling and is present in all physics engines to some extent. The digital (discrete) nature of computers is the root cause of it. Thin and/or fast objects are more prone to tunneling.

You can learn more about tunneling in this video:


In your case, your best bet is to try using more substeps (found in the ObiFixedUpdater component) or decreasing your fixed timestep (In Unity's Time manager). Still, given high enough velocities, ropes will pass trough each other (as would any object in any engine).

[canerozdemir]

Can't be prevented in all cases. This issue is called tunneling and is present in all physics engines to some extent. The digital (discrete) nature of computers is the root cause of it. Thin and/or fast objects are more prone to tunneling.

You can learn more about tunneling in this video:


In your case, your best bet is to try using more substeps (found in the ObiFixedUpdater component) or decreasing your fixed timestep (In Unity's Time manager). Still, given high enough velocities, ropes will pass trough each other (as would any object in any engine).

Increasing the substeps caused a fps-drop in my case, however, increasing the particle collision on the solver made it more stable. So, I am going to use that approach for now to at least providing a temporary solution. Thank you for the help and suggestion. I will learn more about tunneling.