Sketch tools are available for manual placement of a rebar shape within a valid host. Rebar sketches will map to an existing shape when they share the following attributes:
If the sketch does not match an existing shape, a new shape will be created in the Rebar Shape browser and Rebar Shape type drop-down in the Options Bar.
Place rebar with sketching tools
Reinforcement panel
Rebar.
Placement Orientation (or Placement Perspective) panel

Sketching a rebar shape
Optional. Click Modify | Create Rebar Sketch tab
Reinforcement panel
Multi-planar to create multiplanar rebar.

Adding rebar hooks to the sketched shape

Mode panel