Real-time Simulation Modes 



Simulation modes overview @3:45

When you just begin a new scene Lucid is not active by default. To see any effects from Lucid you need to manually begin the simulation. This will detect any objects currently in the scene which are configured to be simulated with Lucid, add them into the simulation, and start simulating them according to the type of real-time simulation which you choose.


Types of real-time simulation 

Depending on behavior you need to adjust your simulation, there are three different types of simulation available:


Incremental Simulation 

  • Begins simulation at start of animation range.
  • Simulation is advanced only when moving time slider forward (or if animation is playing).
  • Simulation is advanced one step at a time regardless of many frames time slider has been moved, as such it does not guarantee a sync with key-based animation within the scene.

This type of simulation is typically useful for manually scrubbing the timeline while keeping Max responsive.


Locked Simulation 

  • Begins simulation at start of animation range but current time slider position is not changed.
  • Simulation is advanced step by step until the current frame is reached.
  • If scene or current time slider position changes, the simulation is re-calculated from start until current frame.
  • If current frame is moved forward in time the simulation happens only for the extra frames since the last one. As such, scrubbing simulation forward is usually quick but scrubbing it backward can result in slower performance.
  • Guarantees sync with scene key-based animation.

This type of simulation is similar to working with particle systems like PFlow.


Live Simulation 

  • Begins simulation at start of animation range.
  • Simulation is "played" in real-time as fast as the system resources will allow.
  • Scene time slider is not affected and can be moved manually.
  • No sync happens with key-based animation.

This type of simulation is good for sitting back and watching things unfold without having to scrub the timeline or using 3dsmax's play controls.


How to change current simulation mode and state 

Default simulation mode is Incremental. You can change the current simulation mode through:
  1. Lucid toolbar by using the first button containing a fly-out with more buttons for each simulation mode
  2. Lucid main menu by clicking the Toggle Lucid Physics entry
  3. MaxScript by typing in one of the commands below into the listener

MaxScript access 

Following MaxScript functions control Lucid simulation:

-- Begin simulation (does nothing if already simulating)

-- When simulating in non-live mode, advances the simulation by one frame

-- Stop Lucid simulation (does nothing if not already simulating)

-- Returns true if currently simulating
isStarted = LucidIsStarted()

-- Starts simulation and scene animation playback

-- Gets the currently used simulation type as 0-based integer value
simulationType = GetSimulationType()

-- Sets the currently used simulation type (0 - incremental, 1 - locked, 2 - live)
SetSimulationType simulationType




When pressing Sandbox or Record buttons simulation doesn't start 

  • Cause 3: You do not have correct device selected for CUDA computing
  • Solution 3:
    1. Open NVidia Control Panel in Windows Control Panel dialog
    2. In the items view choose 3D Settings -> Configure Surround, PhysX
    3. under PhysX Settings -> Processor select Auto-select (recommended) setting

When trying basic simulations or sample scenes driver error appears 

  • Cause 1: Your computer might have incorrect CUDA driver
  • Solution 1: Please try downloading and running NVidia Flex Demos to see if they run fine. If they run without problem, please contact support. Otherwise you might need to update your graphics card driver.
Missing Something? Let us know if this page needs more information about the topic.