Moldings along a sloped wall?

[James W. Johnson]

I am having a problem adding molding to the top of a sloped wall. I am using the extrude along path tool and as the slope of my walls change the profile of the molding seems to rotate. You'll see what I mean in the attached drawing.

[Horst M.]

Hallo James,

I had a similar effect recently when I used the Extrude Along Path for a relatively Complex Shape of a Guardrail/Handrail.

My only way to solve the Problem, was to cut the Path in Sections,

extrude the Sections independently with copies of the Profile, and then cut them in the Corners, where they meet.

Somehow like you would built it. :-)

Edited April 12, 2010 by Horst M.

[Pat Stanford]

When you do the Extrude Along Path, check the Lock Profile Plane check box. This will keep the profile from rotating.

[Horst M.]

Hi Pat,

Could be, that I'm overseeing something simple again, but I tried with

Locked Profiles as well, but the results were still not what I expected

I did it now with the Example of James, and attached the Result.

The beginning and the end look fine, but the midsection seems still turned.

And there is also a Problem where the 2nd and the 3rd section join.

[Pat Stanford]

Yes, I see the problem here also. I only check the two ends. I don't have time to do an in-depth analysis right now.

The work around would be to do as Horst suggests and do each segment separately.

It would be great if you could submit the file as a bug report. See the Bug Submit link at the top right of the page. It seems that this should be an easy thing to do.

[James W. Johnson]

Thanks for all your suggestions! I'll continue to play with this as I have time and post an answer if I find one.

[islandmon]

Usually, I model the inner & outer angles separately and place them as symbols.

This making editing the various runs quick&easy.

This also provides a Library of the various connections for later use... works great with guttering, too.

[Danielj1]

I just tried this (and filed a bug report too). Here's what I found: a two-segment NURBS curve path (meaning L-shaped) won't display the problem, but a three-segment one (U-shaped) will. In addition, adding the fourth vertex (meaning the third segment) sometimes causes the extrusion's profile to be located at a different angle relative to the path.

So in this particular case, I'd use more than one path in sequence, each with no more than two segments. Let's say you're creating a three-segment path for your extrusion, similar to the one shown in your illustration. I'd consider making two, two-segment paths (for the purpose of this first modeling step place them side-by-side without overlapping). The first one modeling segments A and B, and the second one modeling segments B and C.

Once the models are done, ungroup everything and delete segment B from one of the models. Then move the remaining segment C over the first model, snapping to the appropriate corner, group it all, and you should now have a three-segment model with the corner joints represented properly.

Dan J.

Edited April 13, 2010 by Danielj1

[Horst M.]

There are two independent Problems

in James Example Handrail experiment:

1. The Connection of the 2nd and 3rd Segment (see my previous Post) is just impossible! Thats not a bug!

There is no way to cut the EAP's of the two Segments in a way to achieve a smooth transition. (Assumption to be disproved :-)

2. The twisted EAP in the 2nd (middle) Segment caught my interest

I did some Experiments with a surprising result:

If you do a EAP with a simple Profile (rectangle) on a Nurbs Curve in Y Direction (just 2 Verticies with different Z hights) the Result is twsited!

If the you use the same Nurbs Curve in X direction, the result is OK!

I think this a bug...

Files attached

Edited April 13, 2010 by Horst M.