When you click Simulate when a simulation already exists, the button's effect depends on which settings you have changed.
Simulation parameters are the parameters that are used as input to produce the simulation. Changing a simulation parameter causes simulation to occur when you click 
again. Most parameters are associated with an environment object—a flow, idle area, or seat—or a selection set of one type of environment object. A few affect all environment objects. This section describes what happens when you simulate after changing various simulation parameters.
General Parameters
| When you do this ... | This happens after you click Simulate |
|---|---|
| Change the number of frames in the simulation | Everything simulates again. |
| Click Delete People | Everything simulates again. |
| Change the appearance of the crowd | Nothing changes: This change occurs interactively. |
Flows
| When you do this ... | This happens after you click Simulate |
|---|---|
| Change a setting on the flow's Flow rollout | All flows simulate again. |
| Edit the geometry of a flow | All flows simulate again. |
| Add or delete a flow | All flows simulate again. |
Idle Areas
| When you do this ... | This happens after you click Simulate |
|---|---|
| Change a setting on the idle area's Idle Area rollout | The idle area simulates again. |
| Edit the geometry of an idle area | The idle area simulates again. |
| Add an idle area | The new idle area simulates. |
| Delete an idle area | The people on the deleted idle area disappear. |
Seats
| When you do this ... | This happens after you click Simulate |
|---|---|
| Changing the Gender or Single setting on the seat's Seat rollout
Note: Changing the Height setting adjusts the motion interactively, so this has no effect on Simulate.
|
The seat simulates again |
| Moving or rotating a seat | Any seat whose status as a talker, listener, or Single changes will simulate again. |
| Adding a seat | The new seat simulates, and so does any seat whose status as a talker, listener, or Single is changed by the new seat's positioning. |
| Deleting a seat | The person on the deleted seat disappears. Any seat whose status as a talker, listener, or Single is changed by the seat removal simulates again. |
Edits to Selected Individuals
When you edit selected people you don't need to click Simulate. If you later make a change that requires you to click Simulate (the cases listed above), Populate attempts to retain the changes you make. This is not always possible. For example, if you change a standing idler to be high resolution, and then you decrease the density of the idle area so that fewer idlers appear, the high-resolution person might appear in a different place, or might be deleted.
| This happens after you click Simulate | |
|---|---|
| Regenerate Swap Appearance Switch Resolution |
The change is maintained unless it is not possible to do so. The person might appear in a different place, or might be deleted. |
| Resimulate | The changed, individual simulations are lost. |
| Delete | The deletion is lost and the deleted characters reappear. |