Help Issues trying to trap object in cloth

[taehong.ahn]

I am trying to implement a landing net for a VR fishing game but I am having trouble keeping an object inside the net. The collisions seem to work well at times but the fish pierces through the net too easily. I have tried changing every setting possible with the information I gathered from the docs and the forum but I have yet to see any sign of success. Currently, the fish flies away with even a little bit of force from the rope but if I increase its mass to solve this problem the rope struggles to pick the fish up because it's too heavy. 

Below are the things I have tried alongside a video and images of the problem at hand. Any ideas on what I am doing wrong?

Things I have tried: 
ObiSolver

• Increase Substeps
  
• Enable/Disable Interpolation
  
• Change Synchronization
  
• Modify Collision settings (CCD, Collision Margin, Max Depenetration, Set Surface Collision Iterations to max)
  
• Increase constraint iterations and try both Sequential and Parallel (Distance, Collision) 
  

ObiCloth

• Use different Cloth/Rigidbody mass ratios (If fish is too heavy relative to cloth, it pierces easily. If it's the other way around, the fish becomes too bouncy)
  
• Enable/Disable Surface Collision (Increase particle radius when disabled, decrease when enabled)
  
• Use different combinations of Stretching scale and compliance
  
• Add high friction/stickiness Obi Collision Materials to cloth and rigidbody.
  
  

   

   

   

[josemendez]

Hi,

How are you moving the net and where's the solver placed, relative to the handle of the net?

I ask because the video looks as if the simulation is performed in the handle's local space instead of world space (there seems to be no inertia to the cloth, and it behaves rather weirdly as if rigidly parented to the handle). If the handle moved by simply setting its transform position, such a setup will basically teleport the cloth around from one frame to the next causing collisions to be largely ignored due to tunneling, no matter what settings you use.

If this is the case, take the solver component out of the handle. That should improve simulation.

kind regards,

[taehong.ahn]

Hi,

Thanks for the quick response. You were right about the solver being in the net object that was a child of the user's right hand. Taking out the solver solved the problem. 

Another question I have is, if the solver and the actor should be independent of the object they are connected to, is there an easy way to position the actor in the way I want it to be? From what I understand I can't put the actor as a child of my desired object since it has to be under a solver, and I can't put the solver on the moving object because the position change will cause issues like mine. Then how can I easily place the actor so that the particles align exactly the way I want it to without taking advantage of relative position? 

Thanks in advance

[josemendez]

Another question I have is, if the solver and the actor should be independent of the object they are connected to, is there an easy way to position the actor in the way I want it to be? From what I understand I can't put the actor as a child of my desired object since it has to be under a solver, and I can't put the solver on the moving object because the position change will cause issues like mine. Then how can I easily place the actor so that the particles align exactly the way I want it to without taking advantage of relative position? 

You simply attach the particles around the border/edge of the cloth to your handle. There isn't any need for the cloth to be a child of the handle for them to move together.

This is the same thing you'd do with rigidbodies + joints in Unity: to make a rigidbody move along with another object, you attach it using a joint instead of parenting its transform (since a parent-child relationship completely bypasses physics, which is the issue you were having).

Also keep in mind that actors need to have a solver up their hierarchy, but they don't need to be direct children of it.

kind regards,