fitting a bezier curve or nurbs to an existing set of points

I have a centerline model of that I would like to use as the path for a bezier shape; however, it is an imported dxf, so it is points and lines. Any idea on how I can either accurately draw or fit a bezier curve to it?

Thanks.

Rob

I’m surprised you didn’t see this:

https://blenderartists.org/forum/viewtopic.php?t=54804

%<

I did see it, but it seems to be an approximating spline. I have a simple tripod of boomerangs that meet in the middle of their apexes. It is a dxf file. I need to fit a spline to the curve of points. Thanks.

Rob

Here’s a link to the blend of the points: www.hermandesign.us/blender/TripodRPH.blend

I can’t get that file, just code.

%<

You need to right-click it and pick, “Save Target As…” or “Save As…”

Thanks.

Rob

It works, but you have to do some work. Split each leg into a seperate obj, connect the verts with edges and run the script on each.

%<

Thank you, it worked. But, the curve created only extends to the next to last point, and not the end points on the curve. Is there a way to have the curve use the endpoints not only as control points? I tried splitting the last vert and making an edge, but it didn’t work. Thanks.

Rob

Dunno… that didn’t happen to me, but then I did only one leg.

%<

In Edit mode, I simply had to select Endpoint under F9 to make the endpoints part of the visible curve. Now, I have what seems a Blender glitch, I can not overcome too easily. I am updating the link if anyone wants to see what I am talking about. The extrude along path twists right in the middle of my boomerang. The T-section inverts with a 180 degree twist midway through my geometry. Any new work arounds for this one? Thanks.

Rob

Yep, Z-Axis blues:

http://membres.lycos.fr/bobois/Tuts/Extrusion_par_bev_ob/Alignement_des_axes/Alignement_des_axes_en.html

%<

Well, I’ve tried all sorts of rotations of the local axis of the verts of my T-section to no avail. Is there a way to copy the lower half of the curve of the boomerang with its z in the same direction as the upper half? I am trying to use Blender instead of Max at work since we only have 1 Max license and I prefer Blender. Do I need to rotate the boomerang and not the profile. BTW, the boomerang curve is the path and the T-section is the profile. Thanks for your quick and ready replies, Fligh %. You’re always there.

Thanks.

Rob

You can try add in an Empty, rotate it, then Ctrl-C, Rotation. You may have to try it with the empty at a few different rotations and possible also Switch Direction on the curve, W in Edit mode.

%<

Fligh %,

I notice that both my profile and the curve local axis are exactly the same. Do I want to make the profile orthogonal to the curve? Also, how can I rotate the T-section, the profile, in Edit mode in whole? When I select all verts of the T-section and try a rotate in x, xx, y or yy it squishes and stretches. I want to flip it 90 degrees on one axis as a whole. Thanks.

Rob

Can you post the file again please?

%<

Same link, latest file. Thanks, Fligh %

Rob

I wish Blender had some primitive snapping capability, not snapping to grid, but to vertices. Does it?

Rob

Yes, even the primitive part! In Edit mode Shft-S, Cursor to Selection, select other, Shft-S, Selection to Cursor.

http://blender.isoserv.com/uploads/TripodRPH2.blend

%<

Fligh %

Did you do a loft by placing the profile at each point? Did you rotate the three legs for any particular reason? I am wondering why the rendering seems to smooth the web and flange together towards the bend in the path. Thanks again.

Rob

To tell you the truth I don’t remember everything I did because I was doing different things in 3 different files, but it goes something like this.

I joined all 3 (Ctrl-J) and rotated it R, X, 222. That got rid of the kinks. Then I seperated each leg §, and worked on each seperately. Selected all points and tilted them (T in Edit mode) till the top of the “T” was inside.

Part of the problem you mentioned earlier about the T-Profile distorting may have had something to do with the fact that you had Proportional Edit Tool on (in the second file you sent).

seems to smooth the web and flange together towards the bend

I noticed that too. For the amount of work you did I think it may well have been easier to have used the point cloud as a reference and built the whole thing in Mesh. Curves in Blender just don’t cut it.

%<