The Vertex utility can be used to add a 3D vertex in 3D space that you can catch to while creating and modifying 3D curves. It is the 3D equivalent of the 2D Construction Point used when creating 2D profiles.
A 3D vertex is a wire part, for which you must give a name, but is in effect a 3D curve having zero length. You can specify a vertex by clicking a point on existing geometry or by specifying its coordinates. The Catch tool can be used to catch to existing geometry.
To create a vertex in 3D space,
1. Click 3D Geometry and then, in the 3D Point group, click Vertex 3D. The Vertex dialog box opens.
2. Type a name for Part.
3. Specify the vertex point:
◦ Click point(s) in the viewport.
◦ Catch to existing 3D geometry.
◦ Type the 3D coordinates in the user input line and press ENTER.
Vertex 3D. The Vertex dialog box opens.
to complete the operation.