Physics Core#

Overview#

The NVIDIA Omniverse™ Physics simulation extension is powered by the NVIDIA PhysX SDK. Below you can find a list of the main features of PhysX that are available in Omniverse.

Physics Core Components#

Getting Started#

The physics simulation extension omni.physx.bundle is enabled in Omniverse USD Composer by default - if you are using another Omniverse App, you may enable the physics extension in the Window > Extensions window.

Omniverse Physics Extensions Overview#

Omniverse Physics consists of many extensions, there is a convenient omni.physx.bundle extension that groups together the most useful extensions and also gathers the changelog. The omni.physx.bundle extension has dependency on these extensions:

Omni PhysX Bundle Extensions Overview

  • Green color represents core extensions required for physics simulation, this core is dependent only to USD and Carbonite, its the minimum set of extensions required to run simulation. Works for any headless mode, no direct Kit connection.

  • Cyan color connects omni.physx with Kit StageUpdate, this is the minimum requirement to get stage simulated if opened in most Kit based apps.

  • Blue color general bundle containing recommended extensions to work with physics, all these extensions belong to omni.physx.bundle and are recommended for full physics experience

Additionally, there are many standalone extensions to extend the physics capabilities within Omniverse:

Omni PhysX Additional Extensions Overview

Omniverse Physics Extensions Overview#

Omniverse Physics consists of many extensions, there is a convenient omni.physx.bundle extension that groups together the most useful extensions and also gathers the changelog. The omni.physx.bundle extension has dependency on these extensions:

Omni PhysX Bundle Extensions Overview

  • Green color represents core extensions required for physics simulation, this core is dependent only to USD and Carbonite, its the minimum set of extensions required to run simulation. Works for any headless mode, no direct Kit connection.

  • Cyan color connects omni.physx with Kit StageUpdate, this is the minimum requirement to get stage simulated if opened in most Kit based apps.

  • Blue color general bundle containing recommended extensions to work with physics, all these extensions belong to omni.physx.bundle and are recommended for full physics experience

Additionally, there are many standalone extensions to extend the physics capabilities within Omniverse:

Omni PhysX Additional Extensions Overview

Explore Physics demos#

A great starting point for exploring physics are the demo scenes available in Window > Simulation > Demo Scenes: Just load a scene and hit play (see highlighted play button in the screenshot). We introduce the basic elements of a physics simulation with the Box on a plane snippet:

Basic Physics (UI) Elements

Physics Authoring Toolbar#

Important to mention is the Physics Authoring Toolbar, which can be used to streamline your physics authoring user experience. Follow the link below to enable and learn more about it.

Setting up physics#

There are three key primitives (prims) on the snippet stage:

  1. The physicsScene prim provides simulation parameters such as gravity direction and magnitude, the simulation time-step size, and advanced solver algorithm settings.

  2. The boxActor prim is a cube shape that has rigid-body dynamics: it spins and falls under gravity.

  3. The groundPlane is a simple mesh that is configured as a static collider: It does not move but the box can collide with it.

You can configure the three prims, and their physics properties in particular, through the Property window (Window > Property). For example, the rigid-body options for the box reveal its initial 180-degree-per-second spin around its x-axis.

You can easily recreate the snippet setup with the following steps (you may want to clear the stage first with File > New):

  1. Create the ground plane mesh with Create > Mesh > Plane. You can scale it in x and z to make it larger.

  2. Configure the plane mesh as a static collider by right-clicking it in the viewport or stage tree, and selecting Add > Physics > Colliders Preset.

  3. Create the cube shape with Create > Shape > Cube and move it up above the plane, so it can fall.

  4. Configure the cube as a rigid body analogous to the plane but selecting Add > Physics > Rigid Body with Colliders Preset. Set its initial rotational velocity in x to 180 deg/s in the property window, see highlight above.

  5. Create the physics scene with Create > Physics > Physics Scene.

  6. Hit play and watch the cube spin and fall onto the plane.

Note that a shortcut to creating the ground plane is Create > Physics > Ground Plane.

Simulation Control#

There are a number of menus you can use to manage simulations. Also a Physics Camera Extension is available for dynamic camera control during a simulation.