Mocap bodies are the weld root of their own kinematic subtree.

PiperOrigin-RevId: 960212286 Change-Id: Ibeff129c3110576c8846c76ba6ab756f23c0fa2e
2026-08-06 04:09:41 -07:00
parent 0accc5b3c7
commit ed13bf5647
19 changed files with 260 additions and 63 deletions
@@ -53,6 +53,12 @@ Engine
   - Changed the default value of :ref:`bvactive<visual-global-bvactive>` from "true" to "false". This avoids
     unnecessarily clearing bounding volume hierarchy visualization flags at every simulation step, which can be a
     bottleneck for models with large meshes.
+   - Mocap bodies and their dof-less descendants are now the root of their own weld group: ``mjModel.body_weldid`` of a
+     mocap body equals its own id rather than 0. Consequences: dragging a mocap body into sleeping objects now wakes
+     them; children of mocap bodies receive standard :ref:`parent-child collision filtering<SurprisingCollisions>`;
+     mocap bodies no longer count as static geometry for ray casting, and contact-matching sensors aggregate their
+     contacts under the mocap body rather than the world; and geom pairs where neither body can move no longer generate
+     contacts.

 Models
 ^^^^^^