I Need Help, B-Spline in AutoCAD 2002

I know there is a Spline command in the AutoCAD.

Can I create a B-spline which has two endpoints and two control points in AutoCAD similar as the one in the Solidworks?

Yes. Generally, the default setup is Fit but can be changed to CV via the Method option.

Command: _spline

Current settings: Method=Fit Knots=Chord

Specify first point or [Method/Degree/Object]: m

Enter spline creation method [Fit/CV] : cv

Yes. Generally, the default setup is Fit but can be changed to CV via the Method option.

 

Command: _spline

Current settings: Method=Fit Knots=Chord

Specify first point or [Method/Degree/Object]: m

Enter spline creation method [Fit/CV] : cv

Since when this feature available in AutoCAD?

Can someone draw me a B-spline in AutoCAD 2002?

BezierB.dwg

You can draw quadric or cubic b-splines in AutoCAD 2012 so why bother going all the way back to 2002?

Here is what you need to do. Use the SPLINETYPE command to change between true quadric b-splines and true cubic b-splines. This is done by setting the value to either 5 (for quadric) or 6 (for cubic). Note that the variable SPLINESEGS controls the fineness of the b-spline. That is it sets the number of line segments in the control frame.

I have combined your threads and moved to the AutoCAD 2D Drafting, Object Properties & Interface forum.

Since AutoCAD 2000 (maybe earlier) via Splined Polyline as ReMark outlined. Since 2009 (maybe earlier) directly from the Spline command. See attached.

BezierBInAutoCAD.dwg

Since AutoCAD 2000 (maybe earlier) via Splined Polyline as ReMark outlined. Since 2009 (maybe earlier) directly from the Spline command. See attached.

Can you please tell me more detail of how to do it?

In post #2 of this thread I pasted what would be shown in the AutoCAD command line for the procedure. So, essentially, all that needs to be done is start the SPLINE command, AutoCAD will show you the current settings (if everything is still set as AutoCAD’s original default setup you would see this:

Current settings: Method=Fit Knots=Chord

Specify first point or [Method/Degree/Object]:

For a Control Point based spline the Method needs to be changed - type “m” at the prompt and hit the ENTER key.

CV is the designation AutoCAD uses for Control Point (CV stands for Control Vertices) – type “cv” then hit the ENTER key.

Select the start point, next control point, next control point, end point.

In post #2 of this thread I pasted what would be shown in the AutoCAD command line for the procedure. So, essentially, all that needs to be done is start the SPLINE command, AutoCAD will show you the current settings (if everything is still set as AutoCAD’s original default setup you would see this:

 

 

 

Current settings: Method=Fit Knots=Chord

Specify first point or [Method/Degree/Object]:

 

For a Control Point based spline the Method needs to be changed - type “m” at the prompt and hit the ENTER key.

 

CV is the designation AutoCAD uses for Control Point (CV stands for Control Vertices) – type “cv” then hit the ENTER key.

 

Select the start point, next control point, next control point, end point.

What about the step in AutoCAD 2002?

Type SPLINETYPE at the Command prompt and make sure it is set to 6. Use the PEDIT command to join the 3 lines in your drawing together into a polyline. Also use the PEDIT command to set the Spline option to the newly created polyline.

You should now have a curve approximating the spline, though is actually multiple small line segments. Those line segments could have been smaller – thus making a better approximation – by modifying the parameters via the SPLINESEGS variable.

If you want better than an approximation, invoke the SPLINE command and use the "Object" option. Now select the multi segment poly to convert it to a Control Vertex Spline.

Type SPLINETYPE at the Command prompt and make sure it is set to 6. Use the PEDIT command to join the 3 lines in your drawing together into a polyline. Also use the PEDIT command to set the Spline option to the newly created polyline.

 

 

 

You should now have a curve approximating the spline, though is actually multiple small line segments. Those line segments could have been smaller – thus making a better approximation – by modifying the parameters via the SPLINESEGS variable.

 

 

 

If you want better than an approximation, invoke the SPLINE command and use the "Object" option. Now select the multi segment poly to convert it to a Control Vertex Spline.

Thank you.