Joint Inspector

The isaacsim.gui.property extension provides a standalone Joint Inspector window for Adjusting per-joint values across the robots present on the stage.

Opening the Window

Open the inspector through Tools > Robotics > Joint Inspector.

The window docks to the left of the viewport.

Selecting a Robot

The header exposes a robot picker, a refresh button, and a + New Inspector button.

• Robot drop-down – lists every prim on the stage that has IsaacRobotAPI applied. Click the drop-down to open a searchable popup; type any substring of the prim path to narrow the list. Selecting a robot rebinds the table to that robot’s joints.

• Refresh – rescans the stage for prims with IsaacRobotAPI. Use this after authoring a new robot in a script editor or after switching layers.

• + New Inspector – spawns an additional Joint Inspector window. Each window keeps an independent robot selection and column set, which is useful for side-by-side comparison of two robots or two views of the same robot.

The window listens to stage open/close and asset-load events so the robot list refreshes automatically when assets finish loading.

Filtering Joints

A search field above the table filters the joint rows by name. Two matching modes are supported:

• Substring (default) – a case-insensitive substring match against the joint short name and the full prim path. arm matches shoulder_arm_joint as well as /World/UR10/shoulder/arm.

• Glob (``*`` or ``?`` in the query) – fnmatch-style wildcards. The query is also matched in a substring-fenced form (*pattern*) so hand* finds anything that contains hand, mirroring the typical search-bar mental model.

A clear button on the right of the field removes the query and restores the full list.

Choosing Columns

The hamburger button on the right of the toolbar opens a categorized columns popup.

The popup contains:

• Backend pills at the top – PhysX and MuJoCo toggle the visibility of every column belonging to that simulation backend. The pill state does not flip the per-column checkboxes, so re-enabling a backend restores the previously checked columns.

• Categorized checkbox rows for the available column groups.

The available column groups are summarized below.

Group	Backend	Columns
Joint Limits	USD / PhysX	Position Min, Position Max, Velocity Max.
Drives	USD	Max Force, Target Position, Target Velocity, Stiffness, Damping.
Performance Envelope	PhysX	Max Actuator Velocity, Speed-Effort Gradient, Velocity-Dependent Resistance.
Joint State	PhysX	State Position, State Velocity.
MuJoCo Joint	MuJoCo	Armature, Damping, Stiffness, Friction Loss, Spring Ref, SolRef Limit (timeconst), SolImp Limit (dmin).

Column behavior:

• Items whose backing API is not applied on any joint of the current robot stay clickable but render dimmed; their tooltip explains why the column is currently empty.

• The user’s column selection persists across robot switches. A column reappears as soon as a robot whose joints back the column is selected.

• Joint Limits columns belong to USD core schemas and are not affected by the backend pills.

Per-axis fan-out

When every joint authoring a multi-apply schema has at most one axis applied (the common case for revolute and prismatic chains), the per-axis dimension is collapsed and the column appears once. The cell automatically picks the joint’s authored axis or its natural axis (angular for revolute, linear for prismatic).

Multi-DOF (for example, D6Joint) joints make the column fan out: one column per distinct axis (transX, transY, transZ, rotX, rotY, rotZ) is rendered, with the axis token appended to the header label.

Editing Values

Each cell is a free-form ui.FloatDrag bound directly to the underlying USD attribute. Drag horizontally to scrub the value or click to type a number. double-click or Ctrl-click to type a number.

Behavior of empty cells, multi-row edits, and array-typed attributes:

• Cells whose backing API is not applied on the joint render empty rather than as a disabled 0.0 field. This avoids implying a meaningful zero where no value is authored.

• Click rows to select them. Ctrl / Cmd and Shift allow multi-row selection. Editing one cell of a selected row mirrors the new value to the same column on every other selected row whose attribute exists.

• The MuJoCo solreflimit and solimplimit columns surface only the dominant element of the underlying array (timeconst and dmin); the rest of the array is preserved on write.

The status line above the table shows the number of joints currently displayed.

Default Visible Columns

The first time the inspector is opened, the following columns are visible:

• Position Min and Position Max (Joint Limits)

• Target Position, Stiffness, Damping (Drives)

• State Position (Joint State)

• Armature, Damping, Stiffness, Friction Loss (MuJoCo Joint)

Use the columns menu to add or remove columns from this set.