Modeling with advanced techniques > 3D curves > Create a 3D straight line
Create a 3D straight line
A straight line is the most basic 3D curve element that you can create. The start and end points of a 3D straight line are both defined by three coordinates in 3D space. The additional third coordinate differentiates this type of line from a 2D straight line, which is defined by a pair of coordinates in a single plane (workplane). You can define a point in 3D space either by entering its coordinates in the user input line, or by catching to existing geometry.
You can define a 3D straight line by:
a start and an end position.
a start position and a direction and length.
a surface axis.
a start condition and length.
The figure shows a straight line (AB) defined between point A at the origin (0,0,0) and point B at a point with the coordinates (10,5,-20). The sphere S represents 3D space around the origin.
A 3D straight line is a stand-alone wire part (or edge) with two vertices which, when active, is displayed in the default green color of edges on the active part.
The major purpose of 3D straight lines is to be used as 3D construction geometry. For example, you might use 3D straight lines to provide catch targets.
To create a 3D straight line,
1. Click 3D Geometry and then, in the 3D Curve group, click Line 3D. The Line dialog box opens.
2. Type a name for Part.
3. Choose a start condition in the Start Cond box.
Position: Define the position of the curve by specifying points in the viewport.
Edge: Define the position and start condition of the curve in relation to an existing edge.
Face: Define the position and start condition of the curve in relation to an existing face.
4. If you select Position, click on a method to create your line:
2 Pos, then click two points on the workplane.
Pos & Vec, then click a start point on the workplane. Set the direction and length using the Vector 3D CoPilot CoPilot in modify mode. Right-click and Accept the direction.
By Axis, then click an axial face.
Polyline is available with 2 Pos or Pos & Vec. Turn on Polyline to create a new line from the end point of the previously created line without selecting the start point.
5. If you select Edge or Face,
Select an Edge or Face. See the curve connect condition (link).
Specify the tangent position. Click Accept to accept the tangent position.
Specify a length by dragging the arrow or typing a number in the dialog.
6. Click to complete the operation.