Extrude Along Path Curved Surface

[trashcan]

I have a curved cyc wall that I need to create - so it curves in two directions.

 

Here's the path / :

 

My thinking was to do extrude along path, which works if I lock the profile, but then I get an error:

 

 

Figured it out - had to lock and fix the profile. That solved it nicely. Though the mesh seems a little over complex:

 

 

If I add a complete flooring element (by offset and closing my profile), the path gets a lot cleaner but the floor now has this nasty artifact in it:

 

Any ideas? 

 

 

Edited July 9, 2020 by trashcan

[markdd]

It looks to me like the horizontal length of the profile is too long. The other factor to think about is the direction of the Path and the profile. Play around with them.

 

I just did this so definitely possible...

 

You should also try the loft tool in the 2nd mode. I find it more robust, but the drawback is that you can't edit the result.

 

Edited July 9, 2020 by markdd

[trashcan]

Messing around worked if I don't also include a floor surface area in the profile.

 

If I add a floor area to the profile:

 

This is what happens:

 

If I do a capped offset of the profile @ 1/16" here's how it looks:

 

Trying to figure out how to get rid of those artifacts. 

[markdd]

Those artefacts are called Z fighting. https://en.m.wikipedia.org/wiki/Z-fighting
 

you have too much intersecting geometry. 

[Kevin McAllister]

You could use the Extrude Along Path method you're proposing if you build the floor separately and add solids.

 

Here's an alternate approach that's much more flexible -

 

1. Extrude a rectangle that represents the bounding box of your space.
2. Use the 3d Fillet tool to add the fillet curves at the corner and floor. You can do it all at once or they can each have different curves.
3. Using the Shell tool, select the three sides you need to remove and set your thickness as required.

Using this method you get nice clean geometry.

 

Kevin

 

 

Studio Cyc.vwx

[mjm]

sweet!

 

[Pat Stanford]

Vectorworks does not like self intersecting surfaces. This means that inside corners are often tricky. 

 

As @markdd says if your horizontal legs are too long then the "ledge" coming in the X direction interferes with the ledge coming from the Y direction and the extrude can't happen. 

 

This happens with sweeps sometimes also. There is nearly always a work around such as what @Kevin McAllister shows for this case.

[Peter Neufeld]

Hello,

Surely a Loft with one rail?

 

Cheers,

Peter

[trashcan]

@Kevin McAllister amazing work-around. worked like a champ. I needed it to be paper thin (emulating a painted cyc that is flush with the floor and walls), so tweaking the thickness in the OIP until right before I get Z-fighting solves that nicely. 

 

@Peter Neufeld For whatever reason I can't get this method to work. Both of my objects are nurbs curves, but it results in a "could not be created" :

 

 

 

(PS can't believe I'm just learning you can embed an MP4 here and it's actually faster than uploading screenshots for some reason, thanks Peter!)

 

[markdd]

If you want it to be paper thin, then you could use the extract tool in the 3D toolset (extract surface mode) and select the faces of Kevin's workaround that you need. 

 

Click the checkbox 

 

The Faces will be created inside a group.

 

Edit the group and run the Add Solid command on the faces into one solid addition. You can now delete Kevin's workaround object leaving with a Paper-thin Cyc and no z fighting ever.

 

 

Edited July 15, 2020 by markdd

[markdd]

Just looked at your video. The reason the loft surface tool will not work is that as the "floor" sweeps around the top curve, it will crash into itself as it sweeps around the right-angle. Basically the floor is too deep.

 

 If you look at the geometry of Kevin's workaround you will see that a new "floor" surface is created once the arc edge of the Nurbs curve changes to straight line.

 

HTH

[Kevin McAllister]

Lots of good ideas here. If you have a floor that this is sitting on there will always be Z fighting unless one is offset from the other. I think reducing the shell thickness to something like 1mm is likely the solution. Whenever I put something on the floor that has no thickness (eg. a NURBS surface "rug" that has texture but not thickness) I float it about 1mm above the actual floor for this very issue.

 

Kevin

 

[Peter Neufeld]

Also if it doesn't work, in the OIP turn on the 'Show Direction' button. They need to be going in the same direction and if not click the 'Reverse Direction' option.

 

Cheers,

Peter