Help 2 questions

[TheMunk]

1. I simply can't find documentation on the difference between a solver simulating collision or particle collision.
   Can you refer me to where I can read more about this? - sorry, already found it: http://obi.virtualmethodstudio.com/tutor...gence.html - follow up: is it possible to skip particle collision and friction if simulating collision and friction? what are the tradeoffs here?
   
2. If I want to make a loop which looks more like the end of a lasso than a complete circle, how would i go about it? using particle constraints to attach 3 particles together with orientation locked? Or is there a simpler way?
   

[josemendez]

1. I simply can't find documentation on the difference between a solver simulating collision or particle collision.
   Can you refer me to where I can read more about this? - sorry, already found it: http://obi.virtualmethodstudio.com/tutor...gence.html - follow up: is it possible to skip particle collision and friction if simulating collision and friction? what are the tradeoffs here?
   
2. If I want to make a loop which looks more like the end of a lasso than a complete circle, how would i go about it? using particle constraints to attach 3 particles together with orientation locked? Or is there a simpler way?
   

1. Particle collisions are (as the name implies) collisions between particles. Regular collisions, are collisions against colliders. Both are independent of each other. You can use both, either one, or none. So yes, you can completely disable particle collision and particle friction (particles will ignore each other) and simulate collision and friction.
   
   Solving particle-particle and particle-collider contacts has the exact same cost. They're both represented using the same struct. Depending on your particular scene, either could dominate the cost of contact solving. For instance, if you have many particles close together at all times (think a bundle of cables), many particle-particle contacts will be generated. If you have few ropes but many colliders near them, there will be many particle-collider contacts.
   
   Note that contacts are generated speculatively - that is, two entities generate a contact when they are close enough to each other, even if they actually never touch each other-.
   
2. You could either use a dynamic attachment with a intermediate rigid body, or use a ObiStitcher component to create constraints between the particles. Both are a bit cumbersome as of now for this use case, so we're designing new ways to attach particles to particles in editor.