Solving the Simulation

After you have set up behaviors for delegates, you must solve the simulation to generate keyframes on delegates. You solve the simulation by selecting the crowd object and clicking Solve in the Solve rollout.

In order to generate the simulation as quickly as possible, 3ds Max saves delegate keys after the solution is run. Thus, a pause might occur between the end of the solution and return of control to you. Also, any objects linked to delegates are hidden during the simulation.

You will most likely have to solve a simulation several times before it is correct. Watch the animation after the solution is calculated, correct behaviors or delegate parameters as necessary, then solve again.

You can speed up the solution calculation time by decreasing the frequency of keyframes or screen updates. You can also view the solution one frame at a time to help pinpoint trouble areas.

Procedures

To solve a simulation:

Set up a crowd simulation with a crowd helper, delegates and behaviors. See Assigning Behaviors.
Select the Crowd helper.
On the Modify panel, in the Solve rollout, set the Start Solve and End Solve parameters to set the start and end frames for the solution.
Click Solve.
Tip To use the keyboard shortcut for the Solve button, turn on the Keyboard Shortcut Override Toggle and then press the S key to run a solution.

Wait a few moments while the solution is calculated. The progress bar at the bottom of the screen tells you the status of the solution process.

To speed up the solution time:

Under Save every Nth Key, set the Positions and Rotations parameters to a higher number, such as 5.
This causes the simulation to set delegate keyframes every five frames rather than at every frame.
Increase the Solve rollout Display During Solve group Frequency setting to a higher number, such as 100 .
This will cause the display to update with the new delegate locations only every 100 frames.

To troubleshoot the simulation:

In a crowd simulation, it is not uncommon for a short portion of the animation to have a unique problem that doesn't appear on other frames. Use Step Solve to analyze short portions of your simulation when things don't go as expected.

Drag the time slider to the frame at which you want to start solving one frame at a time.
Click Step Solve.
To use the keyboard shortcut for the Step Solve button, turn on the Keyboard Shortcut Override Toggle and then press the T key to run a solution in step mode.

You can start at any frame. Zoom in to examine the vectors of misbehaving delegates.
Press the spacebar to solve the simulation one frame at a time.
Press Esc to exit Step Solve mode.