Can Isaac Sim simulate grass (physics simulation)?

Omniverse Isaac Sim
1

I would like to know if Isaac Sim can simulate grass, such as bending, rebounding, and so on.

I saw that “Blender” has a plugin called “Physical Grass” that can easily simulate the physical properties of grass.

I wonder if Isaac Sim can support this as well.

Looking forward to your help.

3

Simulating grass -including bending and rebounding -in Isaac Sim is possible using the deformable body (soft body) simulation features. However, there are important limitations and workflow considerations in making grass behave physically like real grass.

Deformable Body Simulation Support

  • Isaac Sim supports deformable (soft body) physics on the GPU, which is applicable to simulating flexible objects, including a simplified grass model.[1]
  • Grass needs to be modeled so each blade is a deformable mesh or a collection of deformable elements (finite element mesh or tetrahedral mesh).
  • Setup workflow:
    • Import or create grass meshes (use a 3D modeling tool like Blender to create a custom mesh).
    • Convert the mesh prim to a deformable body using the GUI: Right-click the prim in the Stage panel, select “Add Physics” → “Deformable Body(Deprecated)”.
    • Adjust physical properties such as elasticity, damping, and stiffness to control bending and rebounding.
    • Use Deformable Body visualization tools to inspect mesh subdivisions and simulated deformations.

Or you can try the new Deformables Beta feature in 5.0.0

  • Deformables Beta
  • PhysX supports a new schema for volume and surface deformables, replacing current particle cloth and deformable body functionality. The beta feature set can be enabled in the physics preferences:
  • Edit → Preferences → Physics → General → Enable Deformable Schema Beta (Requires Restart)

Simulating Bending and Rebounding

  • Bending and rebounding depend on the mesh’s physics attributes:
    • Stiffness controls how much a blade resists being bent.
    • Damping affects how much energy is lost in motion, influencing rebounding behavior.
    • These properties are configured in the Physics or Deformable Component attributes of your grass prim.
  • To interact with grass - such as by colliding, stepping, or wind - you assign collision shapes or apply external forces to the deformable mesh.
  • Advanced behaviors (for fields of grass): Use arrayed mesh objects (multiple blades), or generate the grass algorithmically in Python before applying physics and materials.

Limitations and Practical Notes

  • Realistic fields with thousands of deformable grass blades are computation-heavy; usually, representative regions are simulated, or simplified meshes are used.
  • Isaac Sim does not natively provide specialized grass simulation tools like some game engines, so the realism and scale will depend on mesh complexity and GPU capabilities.
  • Granular surface simulation (soil, large-scale interaction with ground) is not currently supported in Isaac Sim.[2]

  1. Interacting with a deformable object — Isaac Lab Documentation ↩︎

  2. Soil Deformation in Isaac Sim ↩︎