Solver Options

The Solver Options or Stopping Conditions in RocFall3 determine when the calculation for a particular rock will be stopped. These conditions are used for both Lump Mass and Rigid Body analyses.

In general, the default settings should be used. However, if you are doing a number of initial analyses, it may be acceptable to decrease the number of steps or increase the velocity cutoffs. Keep in mind that, at a certain point, these parameters will affect the analysis results.

Maximum Steps per Rock

This sets the maximum steps/events for each rock path before the simulation is cut off. As the number of steps increases, the amount of memory and time required for the analysis increases. Note that, if you see that a lot of rocks are stopping based on this condition, you should increase the maximum number of steps in order to find the actual result.

Stopped Velocity Cutoff

The Stopped Velocity is the velocity at which the rock is considered to be no longer moving. For Rigid Body analyses, this is the centroid velocity.

Normal Velocity Cutoff

The Normal Velocity Cutoff is the velocity, at the point of contact, at which the rock transitions from free-falling to being in constant contact with the slope. This cutoff will have an effect when friction starts being considered.

When Lump Mass is being used, this is the cutoff that transitions a rock from free-falling to sliding (constant contact with slope). When Rigid Body is being used, this is the cutoff that transitions a rock from free-falling to ending the algorithm.

Maximum Timestep

This condition is considered in Lump Mass sliding and in the Rigid Body engine. This is the biggest time step taken in the analysis. The smaller the timestep, the more precise the analysis. However, the smaller the timestep, the longer the analysis will take.