You are probably already familiar with most of these settings from the Hair object’s Dynamics tab. These settings function the same way.
Use this setting to subdue the movement of the spline. The effect is that of placing the splines into a liquid or substance with a higher viscosity.
Use this setting to define the radius around the spline within which Collisions should have an effect. The higher the value, the further the spline will sway over the surface of a collision object.
Basically, Stiffness defines to what degree the springs will affect the splines. Low values will offer less resistance to gravitational and other forces, higher values will offer more resistance to these forces. The fewer spline points, the more noticeable the effect of Stiffness will be.
This setting defines the degree of stiffness of the springs between spline points. Lower values result in elastic, springy rubber. Avoid very low values since they will result in strange accordion-effects.
Use this setting to mix the initial state (the starting position you set with the Set Initial button) with the current state of the spline dynamics. The spline dynamics themselves will not be affected and will continue to function as defined, allowing you to change the Rest Mix setting as you wish. You may also, at any time, set the value to 0, which will set the spline dynamics state back to the current position.
Imagine small springs connected on one end to each spline point, and on the other end to each rest position of the spline points. Rest Hold defines the spring strength: 0% has no effect; 100% will hold every point in the rest position.
The effect is similar to fastening several springs to a garden hose along its length.
When guides sway, they will stretch to a certain degree. Raise the Deform value if you want this stretch to last longer. Elastic Limit defines the degree of stretch, up to a lasting state.
Fixating Spline Points
Unlike guides, which normally grow on the surface of an object, splines are always free-floating and would simple fall under the influence of a gravitational force. The functions described below let you affix your spline points.
Spline points are selected using the normal Cinema 4D selection tools.
Activate this setting if you want the anchor points (the fixed points that are not affected by spline dynamics) to be displayed in the editor view. All anchor points will be displayed in purple.
Use the Mass setting to assign mass to your spline points. A large spline point mass will place greater strain on the springs, which will, as a result, be stretched further. A Mass setting of 0 affixes the point (this point will not be moved by the spline dynamics).
Select the spline points you would like to use as anchor points and click on Set. This will fix these spline points and they will not move. Click on Release to unfix anchor points, or click on Clear to delete all anchor points (sets the Mass setting to 0). The spline points will, of course, remain.