Also it can be a lot more difficult for offset to process a whole bunch of joined surfaces like it looks like you have in that case.

It will go through a process where it tries to extend and intersect all the offset pieces with one another, and if those pieces just kind of barely graze one another that can make for a kind of wiggly and badly defined intersection curve which will give bad results.

You may need to do something like offset only a few key surfaces, and kind of construct some inner pieces hanging off of those to build the interior wall.

- Michael

It's also possible that it may be a display bug where the display mesher is not handling some particular arrangement of trim curves properly.

Does it change in behavior and look proper when you export to a mesh format like OBJ?

- Michael

Hi Michael,

More than likely, it's me creating sloppy cuts/curves. I tend to overlook that while prototyping objects. Which, in turn gives me problems later :)

I'm including the 3dm file. I've actually now gone back to my original form (without any windows and such) to extract an inner frame from that. I've noticed there that sometimes the shell will not yield results but the offset works.

As usual, thanks for the quick response.

Tree

Hi Tree,
Thats kindof it. Some of the edge boundries are kindof overlapping. If you look here:




Then zoom in, you will see what is there.

Here is a file back....I deleted the 2 selected pieces you see in this picture and redid the surface. It then will offset or shell.

Hi Tree, looks like Burr has you covered above, thanks Burr!.

> More than likely, it's me creating sloppy cuts/curves. I
> tend to overlook that while prototyping objects. Which, in
> turn gives me problems later :)

Yeah there are a few particular commands that are not very tolerant of inexact kinds of things, most notably Offset, Shell, and Fillet.

The problems tend to be when those commands attempt to extend pieces and then intersect the extensions with one another.

If you have surfaces that kind of come close to one another (in either position or also in tangency) but are not quite accurate it can tend to cause problems and messy results. There tends to be things generated like little slivery connecting pieces, stuff like that.

If you're not planning on doing Offset, Shell, or Fillet, you can tend to be more free to just stick things together quickly without much care, but if you are planning on using any of these commands it is better to take some care to ensure the initial curve framework is all ship-shape to avoid problems.

- Michael

WOW Burr,

Awesomeness! Thanks for taking the time to check that out for me.

Now I know better what to look for in such situations. I guess I was having so much fun just throwing curves, fillets, offsets and the like around that I lost track of a clean model.

Hey Burr (or Michael),

You have any tipps on how I can locate such errors. Do you first do an offset/shell, then see where the errors occur? Or is it possible to find them before doing any operations?

Tree

One more thing Burr.

Maybe you can also give me a quick run-down on how exactly you rebuilt the 2 pieces that you deleted. Just so I get an idea how to fix such problems. Thanks for any help.

Tree

Hi Tree,
After I reviewed the model I sent back to you, I realized it was kindof out of whack with what you had already put in it and wasnt the result you were looking for... Really the base answer has to be doing this type of patch together modeling is going to be very tedious and difficult at best. Sweep is a tool that can be used to patch things like this together, but I would have to stop here with trying to give direction on where to take this. It's probably out of my modeling skillset.

Sorry.

Hi Tree,

> Do you first do an offset/shell, then see where
> the errors occur?

Yeah, that is one method, when you see where there is a problem happening then try to zoom in to that area to more closely inspect what is happening there, are there any little tiny slivery surfaces there, do pieces overlap, stuff like that.


> Or is it possible to find them before doing any operations?

It depends on the situation, but if you're going to be doing stuff like fillets it is best to try and keep your curves aligned when they are initially drawn - things like if you are putting in some lines and arcs don't draw things with snaps turned off and only eyeballing them, use tools that will generate tangent arcs or use tangent snap when drawing lines so that you know things are all set up right off the bat.

- Michael