Physics engine
The software component of Gazebo that computes rigid-body dynamics: contact forces, joint constraints, gravity, friction, and collision responses at each simulation timestep. Modern Gazebo uses DART by default; Bullet and Bullet-Featherstone are the supported alternative engine plugins. ODE (used in Gazebo Classic) is not a standalone engine plugin in modern Gazebo; it survives only as a collision-detector option inside DART. The physics engine operates on collision geometries, not visual meshes.
Defined in 2 GAGE programs, which carry 3 distinct definitions of it. The wording above is taught in Foundations of Robotics and Physical AI.
How each discipline defines it
The same term does different work depending on who is using it. These are the definitions as each program teaches them, unedited.
The software component of Gazebo that computes rigid-body dynamics: contact forces, joint constraints, gravity, friction, and collision responses at each simulation timestep. Modern Gazebo uses DART by default; Bullet and Bullet-Featherstone are the supported alternative engine plugins. ODE (used in Gazebo Classic) is not a standalone engine plugin in modern Gazebo; it survives only as a collision-detector option inside DART. The physics engine operates on collision geometries, not visual meshes.
The software core of a simulator that advances rigid-body dynamics, contact, and constraint equations through time. Gazebo and comparable robotics simulators wrap physics engines with sensor models, robot descriptions, and world scenes.
The mathematical component of a robot simulator that models forces, inertia, friction, and contact dynamics, stepping the simulated world forward in time according to the laws of rigid-body mechanics. Common examples include ODE, Bullet, and PhysX.
Where it is taught
The exact lessons this term appears in. The first module of every program is free with a free account.
- Why simulation is where you learn, break things, and iterate safely · Your First Simulator to Practice In, Foundations of Robotics and Physical AI
- Installing and running the Gazebo simulator · Your First Simulator to Practice In, Foundations of Robotics and Physical AI
- The sim-to-real gap: why it works in Gazebo and fails on the floor · Failure Analysis, Learning From How Robots Break, Engineering Judgment and Professional Formation
Where it shows up at work
A definition is where Physics engine starts. The lessons above teach it inside the competencies below, which are what job descriptions ask for and what the GAGE credential records. Every link here is drawn from the same careers map that builds a role's readiness check.
Understands AI that acts in the physical world: perception stacks, vision language action models, sim to real transfer, sensor fusion, and where each of them fails.
One lesson on this page teach it as a primary outcome.
Roles that hire for it
Each role page shows the full competency set, what the seat decides, and a readiness check against your own evidence.
- Robotics AI Engineer, embodied systems editionneeds it at depth
- Physical AI Safety Engineer, autonomous systems editionneeds working knowledge
How job descriptions say it
Postings rarely use the textbook word. These are the phrases the careers map reads as asking for the competencies above.
One interview question about it
A perception model that scores well in simulation fails on the warehouse floor. Walk me through how you find out why.
Asked of candidates for embodied ai and robotics systems. Answering it in your own words is exactly how a GAGE topic is passed, and the credential records the pass where an employer can check it.
Terms it appears with
Not an alphabetical neighbourhood: these are the terms taught in the same lessons, ranked by how often they appear together.