This page provides information on the Simulation rollout for a LiquidSim object.
The Simulation roll-out contains the main panel controlling the simulation process. It also displays some statistical info like simulation times and the content of the cache file for the current frame. The content may be grid channels such as Temperature, Velocity, etc., as well as particle groups. You can choose the channels from the Output rollout, while the particle groups may be created by the Fire Source | PHXSource, or Splash and Foam sections.
Most simulations require long time to calculate and it's very convenient to let them run during the night. However, you still have to render the result in the morning and this also consumes a lot of time. The Phoenix FD scripting system allows you to execute any action at the end of the simulation, and that includes the rendering as well. You just have to enable the scripting from the Simulation roll-out and open the script text. For more information, see the Nightly Simulation and Rendering section on the Tips and Tricks page.
UI Path: ||Select Liquid Simulator | LiquidSim object|| > Modify panel > Simulation rollout
Start, Pause, Stop, Resume | A_StartSim, A_StopSim – Start, pause, and stop the simulation. Once the simulation has been paused, the option to Resume becomes available.
Load & Start | A_StartSim – Loads the data from a single cache as an initial state for the simulation and starts simulating from the Start Frame the same way the Start action works. The cache can be of the .aur, .vdb, or .f3d formats and so can be imported from a 3rd party software into Phoenix. The loaded grid will be resized to fit the grid's dimensions at the Start Frame. The loaded cache does not need to be a Backup frame or to contain velocity at all - the simulator will load any available channels from the cache file and the rest of the simulated channels will be empty as when starting a brand new simulation. If you wish to smoothly continue a simulated sequence from a given frame, please use the Restore command instead.
Restore | A_StartSim – Continues a simulation from the currently viewed frame on the timeline. This way a Phoenix simulation that has been stopped previously can be resumed from the point you left off, even after the software was closed and re-opened.
Restoring does not work for cache sequences imported from 3rd party software. It is only possible when the full internal state of a Phoenix simulation is exported (controlled by the Backup Interval parameter in the Output rollout). Frames with the full state are called Backup frames. When a Backup frame is currently viewed, the text "Can Restore From Here" appears in the Cache File Content list. The Restore command finds the latest Backup frame up to the current timeline frame and continues the simulation from there.
Preferences... – Opens up the Phoenix FD Global Preferences window.
? – Opens up the Phoenix documentation and information on the current rollout.
About – Opens a splash screen window for Phoenix with information on the version number and access to the log file.
Simulation Presets... | A_LoadRenderPreset – Displays a dropdown menu to either load or save .tpr or .slog files, which hold settings for this simulation.
Start Frame | startframe – Explicitly sets the Start frame of the Simulation. This can also be a negative number. Only available when Timeline (Start Frame) is disabled.
Timeline | parmName - When enabled, the Simulation will run from the Timeline Start Frame.
Stop Frame | stopframe – Explicitly sets the End frame of the Simulation. This can also be a negative number. Only available when Timeline (Stop Frame) is disabled.
Timeline | parmName - When enabled, the Simulation will run to the end of the Timeline.
Use Script | script, use_script – Enables the use ofduring the simulation. Click Edit... to open a window with some skeleton code and a short description of the available commands. For more information, please see the Phoenix MaxScript page.
Threads Limit | maxthreads – Specifies an upper limit for the number of threads used for the simulation. When the value is set to 0, the maximum number of threads (cores) will be used.
NUMA Nodes – If the simulation is executed over a NUMA machine, you can specify which nodes will be used. Phoenix FD is very sensitive to memory transfer and if all the nodes are used, performance might decrease due to low bandwidth between the different nodes.
Note: NUMA stands for Non-Uniform Memory Access. It can be used to restrict the threads used for simulation based on the physical CPUs available on the system (in a multiprocessor systems). In this way better memory access can be achieved when multiple simulations are run on the same machine.
This area displays information on the current simulation. Any data from available channels that have been loaded into the simulator are shown. This includes the minimum and maximum ranges for each channel.
Note that the Container Dimensions show the loaded cache size as seen in the scene, in the currently selected units. This size is not multiplied by the Scene Scale parameter from the Grid rollout. If you want to see how big the container is as seen by the Phoenix simulator when the Scene Scale parameter is used, check the X, Y, Z info in the Grid rollout.