The tree displayed in the Navigator window has nodes of many different types. Nodes can represent 1) a single object in the model or associated with the model or 2) collections of objects (for example, the node corresponding to the set of rigid bodies in a model). Nodes that correspond to multiple objects have a folder-like representation in the navigator tree. 

The following table describes the types of objects that can be represented in the tree and their corresponding icons. Some objects, such as markers, are not represented in the tree in order to present a less cluttered view when dealing with large models.

Node Label	Icon	What the node represents
[Model Name]		A full OpenSim model
Bodies		The set of rigid bodies in the model
[Body Name]		A single rigid body or Ground frame
[Wrap Object Name]		A single muscle wrap object
[Frame]		An offset frame attached to the Body or ground
[Geometry Name]		Geometry (a mesh file, or analytical geometry)
Forces		All forces in the model
Muscles		All Muscles
[Muscle Group Name]		A muscle group
[Muscle Name]		A single muscle
Actuators		All non-muscle actuators
TorqueActuator		A torque
CoordinateActuator		A Generalized force
Contact Forces		A force
Other Forces		A force
Joints		All joints in the model
[Joint Name]		A single joint
[Dof Name]		A function describing dof changes
Dofs		All degrees of freedom for a joint
[Frame]		An offset frame used to define the Joint
Constraints		A list of constraints associated with the model
[Constraint Name]		A specific constraint
Contact Geometry		A list of contact geometry associated with the model
Markers		A list of markers associated with the model
[Marker Name]		A specific marker
Motions		All motions associated with a model
[Motion Name]		A specific motion
Controllers		All controllers in the modle
Probes		All Probes attached to the model
Other Components		Any other custom components that are a part of the model

Selecting Components (Key Bindings)

Selection of nodes in the Navigator tree follows the standard conventions: 

• Select objects by clicking the left mouse button once on the tree node
• Select a region of contiguous nodes in the tree using shift+left mouse
• Clicking ctrl-left mouse button (cmd-left mouse on Mac) on a node that has already been selected causes it to be deselected
• Add objects to a group of selected objects by using ctrl+left mouse (cmd-left mouse on Mac)

In addition, clicking the left mouse button twice (double clicking) a node places a triad on the object in the visualizer. This is useful when quickly navigating the model to investigate where different objects are in the 3D View window. You can use the triad to move the object in the visualizer.