Help Emit rope like silly string

[josemendez]

Where's two clips. Both have "Very sticky" as a collision material

This is "kinematic to particles" which acts the same as with rigid body off, where if the object is still it's fine, but moving it around is strange.

Here you’re not “moving the rigidbody”: you’re setting the transform position. These are two entirely different things. Rule #1 of rigidbodies is do not set their transform values directly during simulation.

When you use the transform gizmos in any 3D software, what they do is “teleport” the object to a new position: they do not apply a force/acceleration/change in velocity to the object using the physics engine (the rigidbody in Unity’s case) so it stands to reason that physics of any kind are entirely ignored when doing this: you will be able to move objects trough walls, move platforms without objects on top staying on them, etc.

Little experiment you can do in Unity: put a box rigidbody on top of a floor, give either of them a material with high friction. Then slide the floor underneath the box to one side: you’d expect the box to move together with the floor due to friction, but it won’t move at all since the floor has *zero velocity*: it’s being teleported around. This is simply how simulated physics works.

This is with a rigid body on the sphere, this sticks to the mesh properly even if it moves but it also slides off. 



What I want is the behavior of the first image, but it stays mostly in place when i move the object rather than slide around. I expect some movement but not like that.

It’s not really possible to do this using physics. The reason is that adhesion and friction are forces, hence affected by mass: for the rope to stick perfectly to a rigidbody the rigidbody must have *infinite* mass, that is, be kinematic. For a non-kinematic rigidbody, you can increase its mass w.r.t. the rope and the larger the mass ratio (that is, the heavier the rigidbody is conpared to the rope) the better the rope will adhere to it, but unless the ratio is infinite adhesion won’t be perfect.

I guess what you’re looking for is just some kind of static parenting? You can do this using contact callbacks to detect when particles touch the sphere rigidbody, then just storing their contact position and moving them there every frame.

Kind regards,