Simulation related FAQ 


Is there a limit to number of particles you can simulate? 

Yes and it could depend on the type of video card you have. At the moment, Lucid has a pre-set limit of 1.3M particles which can be increased in Flex settings helper. You run into a risk of crashing your graphics driver and stability issues if you go past a certain limit. This limit is determined by NVidia Flex, which Lucid uses as its dynamics engine.


Why are my (inflatable, rigid, cloth) objects going through one another? 

Chances are that your particle size is too small or you need to improve the accuracy of the simulation. Lucid uses particle-based collisions which means that particles need to be big enough to collide with one another.
  • In cloth simulations one particle is generated per each vertex so you might need to increase the number of vertices in the cloth mesh
  • Use the Show as Particles option in Lucid modifier to see the actual particles present in the simulation. If they are too small, use the Manual Radius option in Flex settings helper to specify their size.
  • If collisions still don't happen increase the number of Substeps and/or Iterations in Flex settings helper to improve the accuracy of the simulation

When placed far away from origin, my particles do not appear where the object should be. 

  • Problem: If you simulate an object using Lucid modifier, Particle Flow Fluid Operator, or any other method in Lucid and place this object very far from the origin the particles generated appear clipped and located closer to the scene origin than the object.
  • Cause: There is a global "sandbox" object which has a default size and, chances are, your simulated object is out of its range. The sandbox limits are used to ensure simulation stability by disallowing objects to explode or fall into infinity.
  • Solution: There are two ways to resolve this:
    1. Change the sandbox size in Flex settings helper
    2. Add a global sandbox object to the scene and resize it to encapsulate your scene

Lucid Modifier shows original mesh during fluid simulation instead of meshed fluid 

  • Problem: When using Lucid Modifier to simulate fluid and leaving "Show as Particles" unchecked the mesh doesn't change from the original mesh to which the modifier is applied
  • Cause: The Granularity value in Fluid Settings rollup is too high. This causes particles to be meshed into an empty mesh. In this case Lucid doesn't modify the input mesh.
  • Solution: Reduce the Granularity value
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