topic Re: reducing number of nodes in a spline in Modeling

reducing number of nodes in a spline

Anonymous — Thu, 25 May 2023 15:09:35 GMT

we're creating a site mesh from splines (created by magic wanding a referenced autocad file).

there are WAAAAY too many nodes in these lines, and i was wondering if there was a command or process to simplify these lines with out having to remove each node by "hand"....

any suggestions?

thanks!

Re: reducing number of nodes in a spline

Dwight — Wed, 10 Dec 2008 00:06:19 GMT

You could convert the splines into polylines of fixed lengths [linear segments, not best match] using the magic wand settings. Put them on a new layer and turn off the spline layer. Trace the polylines to establish new contours.

You might adjust the interval to quite long lengths depending on steepness....

Re: reducing number of nodes in a spline

Anonymous — Wed, 10 Dec 2008 00:14:37 GMT

just to check, are these the settings i should be adjusting to reduce the number of nodes? i've never messed with the magic wand settings before...

[/img]

Re: reducing number of nodes in a spline

Link — Wed, 10 Dec 2008 00:16:42 GMT

Yes. Keep in mind that you don't have to use polylines. These settings will work with splines too.

Cheers,
Link.

Re: reducing number of nodes in a spline

Anonymous — Wed, 10 Dec 2008 00:17:47 GMT

i've attached the image..

Re: reducing number of nodes in a spline

Anonymous — Wed, 10 Dec 2008 00:23:50 GMT

here's an example of the spline (the grid is set to 4'x4' to give scale)
many of those segments do not need more than one node, is there a way to reduce the number?

thanks for the help so far! i had no idea there were magic wand settings...it makes sense, but i never thought about that...

Re: reducing number of nodes in a spline

Dwight — Wed, 10 Dec 2008 00:32:22 GMT

Link:
Please show an example tracing splines with magic wand tracing splines to reduce node numbers.

In my experience, a magic wand traced spline almost always matches the number of underlying nodes.

Re: reducing number of nodes in a spline

Link — Wed, 10 Dec 2008 01:34:41 GMT

Ahh yes.

AFAIK The Magic Wand 'Linear Segments' does not work with splines, presumably because splines by their very nature cannot contain straight segments (lines). So you still need to magic wand the original spline with a polyline, using linear segments as you described, to get the number of nodes down. And then you need to retrace it with another spline typically using the same settings as the polyline.

Sorry for any confusion or dashed hopes.

Cheers,
Link.

Re: reducing number of nodes in a spline

Dwight — Wed, 10 Dec 2008 01:38:07 GMT

But wait.

He's already got the splines. They stand in quite nicely for the fakery of contour lines. [Themselves, interpolations of grid data]

All we want to do is find a pseudo-automatic way of making plausible nodes for our mesh.

One we use the polyline trick to reduce the nodes, we can throw the jagged polylines away and return to the sensuous splines....

Re: reducing number of nodes in a spline

Link — Wed, 10 Dec 2008 01:43:16 GMT

Well in that case, he doesn't even need the polylines, right?

Cheers,
Link.

Re: reducing number of nodes in a spline

Dwight — Wed, 10 Dec 2008 01:57:27 GMT

You toy with me now.

I did skip the step where you use the magic wand with the mesh tool to take each polyline contour to form linked nodes that can be uniformly edited..... so we can dispense with the polyline contours.

Sheesh.

Re: reducing number of nodes in a spline

Link — Wed, 10 Dec 2008 02:08:49 GMT

Dwight wrote:
You toy with me now.

That was too funny!

Cheers,
Link.

Re: reducing number of nodes in a spline

rocorona — Wed, 10 Dec 2008 10:11:57 GMT

This was an old issue, that worths to me an "ArchiCAd 7" tee-shirt...

Now it is in the Archicadwiki:
http://www.archicadwiki.com/TechNotes/Handle%20huge%20surveyors%27%20drawings

Re: reducing number of nodes in a spline

Anonymous — Wed, 10 Dec 2008 16:05:10 GMT

YES, segment length...it was sitting right there in front of me, duh....fantastic! thanks for the help!!