When you set the mParticles Glue test binding type to Distance, mParticles Glue creates a "rope" binding from each particle to another particle, a deflector, or the ground. The endpoints of this virtual rope are called anchors.
The anchors are placed at the closest points between particle shapes, or between particle and deflector shapes. Once a binding rope is created, its length depends on restrictions that you specify. You can restrict the rope to have minimal length (like a stick to keep particles apart), or maximum length, or both minimum and maximum, or to add spring properties to the rope.
For a video showing the effects of the Minimum Distance Limit option, see Minimum Distance Limit.
Changing this setting doesn't affect interparticle distances at binding time, but if you increase the limit, the particles can move farther apart when acted on by outside forces while remaining bound together.
For a video showing the effects of the Maximum Distance Limit option, see Maximum Distance Limit.
If the distance becomes less than the minimum (when Minimum Distance Limit is on) or greater than the maximum (when Maximum Distance Limit is on), then mParticles Glue attempts to restore the separation to the specified limits by exerting force to move particles apart or together. The magnitude of the force is determined by the Spring Coef setting and the relative deviation of the current binding length from minimum or maximum. That is, the greater the deviation from the specified minimum or maximum distance, the greater the force applied. The dynamics of the force are also defined by Damper Coef setting.
For videos showing the effects of the Enable Spring Force and Adjust By Particle Mass options, see Enable Spring Force and Adjust By Particle Mass.
Use this option when particle shapes are very close to each other (such as touching spheres), with the result that normal binding lengths would be close to zero. By burying anchors under the collision surface, the binding distance is "artificially" enlarged, and the relative motion of bound particles is freer.
For a video showing the effects of the Bury Binding Anchors option, see Bury Binding Anchors.
Breakable By Overstretch is kind of a safeguard to release the bindings if the conditions do not allow the bindings to keep their Maximum Distance parameters.
For a video showing the effects of the Breakable By Overstretch option, see Breakable By Overstretch.