URDF Studio
#Frames & inertia overlays
Two visualisation layers live in the subtoolbar (below the main toolbar).
#TF frames
A per-link XYZ axes helper. The Frames select offers three modes:
| Mode | Effect |
|---|---|
off |
No axes (default). |
selected |
Axes are drawn only on the currently selected link. |
all |
Axes are drawn on every link. |
The helper is sized relative to the robot's bounding radius so it remains visible on both tiny grippers and full humanoid arms.
Useful for:
- Validating that joint origins point where you think they do.
- Spotting accidental rotations between parent and child frames.
- Authoring/debugging a custom end-effector mount.
#Inertia
Check Inertia in the subtoolbar to overlay:
- An inertia ellipsoid on each link with a valid
<inertial>block. The ellipsoid axes are derived from the eigenvalues of the inertia tensor (I = R Λ Rᵀ) and oriented along the eigenvectors. A larger ellipsoid means more rotational inertia along that axis. - A small marker at each link's center of mass.
- A larger marker at the robot's total CoM, weighted by mass.
The Inspector tab still shows the raw tensor components, mass, and origin of whichever link you have selected — see Inspector & link tree.
#Diagnostics that interact with this layer
If a link's inertia tensor is missing, has non-positive mass, or has a non-positive-definite tensor, the Checks panel surfaces it. The ellipsoid for such a link is skipped or rendered with a warning color so you can spot bad data visually. See Diagnostics.