Fixed joint doesn't work as intended for soft body

In the Soft Body demo, icosphere.urdf has a fixed joint between arm and soft body. Usually, a fixed joint between rigid body and another rigid body will make them move together. However, icosphere.urdf produces a ball that doesn’t got lift up when the arm lifts up. This is more like the effect of a free joint rather than a fixed joint.

An important feature of cloth manipulation is welding a mesh point on a softbody to a link. For example, I may attach a point on scarf to finger tip of end-effector. Or, simply support the attractor equivalent for points on softbody. Is it possible to support this feature?

Hi there,

This can be accomplished by setting the attachDistance parameter to a value > 0.0 in the soft link tag in the URDF file.

Particles that are less than this distance to a collision shape will be automatically attached and follow that shape.

Hope that helps.


Your solution works for me. Just set attachDistance value="70", and the ball will get lift up when the arm lifts up.