> ## Documentation Index > Fetch the complete documentation index at: https://dadd.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # > Declaratively add physics bodies to the MuJoCo simulation The `` component lets you add physical bodies (boxes, spheres, cylinders) to the simulation as JSX. Bodies are injected into the MJCF XML before model compilation, so they participate fully in physics — collisions, gravity, grasping, etc. ## Usage ```tsx theme={null} import { Body } from "mujoco-react"; // Physics body with default visuals // Physics body with custom Three.js visuals // Graspable object with contact tuning ``` ## How it works `` registers its definition in a provider-level registry. Bodies present at initial mount are included in the first `loadScene()` call with zero extra reloads. Bodies added or removed after the initial load trigger a debounced scene reload. When `children` are provided, the SceneRenderer skips default geom visuals for that body, and the `` component syncs a `` wrapper to the body's physics pose each frame instead. ## Props Unique body name. Used as the MuJoCo body name in the XML. Geom type for the body. Geom size. Interpretation depends on type — see [MuJoCo geom size docs](https://mujoco.readthedocs.io/en/stable/XMLreference.html#body-geom). Initial world position of the body. Color and alpha for the default geom visual. Ignored when children are provided. Body mass in kg. Whether to add a freejoint so the body can move freely. MuJoCo friction parameters, e.g. `"1.5 0.3 0.1"`. MuJoCo solver reference parameters. MuJoCo solver impedance parameters. Contact dimensionality. Use `4` or `6` for grasping. Optional custom Three.js visuals. When provided, default geom rendering is skipped and the children are synced to the body's physics pose.