I’m using Bsurfaces to make a land surface from contours imported with dxf import from cad file and it works perfectly. The imported contours (polylines in dxf format) were already on the appropriate height in cad and became one object on import, consisting of one spline per contour.
In order for the Bsurfaces to work properly, the splines had to be
- converted to bezier
- run in the same direction, start to end point (some had to flipped)
- and ordered sequentially
1 and 2 can be done natively in Blender, easy enough. To order the splines @cwolf3d suggested loading another add-on he maintains, built into Blender releases, called Curve Tools add-on.
The Utilities section has a Spline Order. You need to turn it on. It will show the serial numbers of the splines (the number is located at the starting point of the spline), then select the desired spline or one point on the spline and use the arrow buttons (’<’, ‘>’) on the panel to change the order.
Also in the utilities are tools to perform 1 and 2, if you are unfamiliar with Blender native for the tasks.
This worked like a gem and completed the workflow to get a land relief from CAD contours.