After a simulation has been configured, it must be run. When a simulation is run, an analytical elevation surface is created, using either the currently visible layers or a custom set of layers. Water movement and pooling is calculated and progressively displayed in the view. As the simulation runs, a cache of key moments is built. Playback controls can then be used to replay or step through the results.
Run a simulation
Once the simulation layer has been added to the scene and configured, the flood simulation can be run. To do this, click the Run button 
in the Build group of the Simulation tab. The simulation begins to play.
As the simulation runs, the time currently being displayed is reflected in the Current time box in the Playback group of the Simulation tab. As each calculation is generated, it displays, the current time value updates to match, and a playback cache is built. The time difference between each cached moment is seen in the read-only Step time box.
To move to a specific instant in time within the simulation, type a new time value into the Current time box and press Enter. The simulation loads the nearest previous cached moment and plays forward from that time.
Use terrain level of detail scaling
When a flood simulation scenario is run, the first processing step collects elevation values from the content in the scene. For the ground elevation surface, you can choose which level of terrain level of detail to use during this process.
For the most accurate result, move the Elevation Precision slider in the Active group of the Simulation tab to the Precise setting. Depending on your scenario and the scene, this may take longer to run. For the fastest processing time, move the slider to the Fast setting. There are four settings on this slider. The view redraws to show which level of detail of the terrain is being used once the simulation begins.
Tip:
- Use a faster setting for initial investigation and then run the scenario at a more precise setting when finer detailed analysis is required.
- There are slight differences in how water flows and accumulates when you switch between each level of detail scaling step.
Playback a simulation
Once the full duration has been generated and played though once, playback controls can be used to incrementally step through the cached results. These controls include the following:
- Move to Start
—Set the simulation to its starting state. - Step Backward
—Move the simulation backward one step. - Play
—Begin animating the cached simulation. - Step Forward
—Move the simulation forward one step. - Move to End
—Set the simulation to its last cached state. - Rain
—Display the 3D visual rain effect while playing the simulation. This is only available in global scene views.
Note:
You can use the playback controls while the simulation is playing, but the time continues to move forward after you click. To use the step or move controls, it is recommended that you first pause the playback.
Rerunning a simulation
If changes are made to the configuration after it has been run, the simulation must be run again and the cache rebuilt to show the new results.
Note:
Symbology changes do not require the scenario to be run again.
In the Build group of the Simulation tab, click the Run button . The existing cache will be removed and a new simulation cache will be generated.
Clearing a simulation cache
A simulation cache is maintained even when a project is closed. If you do not want to save the cache, click the Clear button 
in the Build group of the Simulation tab. You can also configure how individual layers manage their cache on the Cache tab of the simulations' Layer Properties dialog box.