The odd "closed by not proper working face" problem

[harnstein]

Guys,

I love SU but sometimes I really hate it. Seriously.

I have a pretty big and complex projekt to rebuild in 3D.
So as usual I start with importing DWGs to SU, checking them, if neccessary going back to Autocad to make some change, explode things (text) and such.

Then after import I try to find a way through the mess, using several useful plugins like Thomthoms edge tools and find faces plugins to get a start. Then it's a lot of redrawing, tedious closing faces, flipping faces, erasing lines which results in flipped faces which I will flip afterwards again - and so on.

This is what it is, this is not great but still SU is the best choice. You can't automate everything and there IS just always some mess in plans.

BUT, what REALLY stresses me out is the fact, that SU seems to have a devilish sense of humor when it comes to properly closing / preserving faces from properly connected edges.
There is this problem that you can (for some reason as SU's intention is to work different from this) actually have two or more lines in the same place which even makes it more difficult or impossible to close a series of edges to define a face. BUT even if there are only single connected lines making up edges of a face, SU is just NOT drawing it..

Like you have to connect various endpoints and triangulate the area until SU LEARNS that it is a face. This is issue No. 1.

But then even, if you manage to get a stubborn face to appear it might happen that you close a face and suddenly at another place proper faces will be mixed with another surface. This is like fixing things on one end while breaking things at another. This is issue No. 2.

For sure, this does not happen when you start building up your own models, clean and from scratch. But sometimes you have to import plans - and you end up with a mess.

Any tips or hints what could be a solution to this? It does take so much time and nerves, I really have to stop this odd face-fight and get a beer.

Appreciate everything.

Niko

Ths image shows this situation. Should be a proper face. Used to be one even. But as you can see - it's not.

PS: One "hint" I know of is that there might be tiny (tiny!) stray edges with in face areas which will prevent the face from being drawn. Sometimes you can track them, sometimes plugins like eg. Thomthoms edge tools are really time- or lifesavers.

---

[Dave R]

Often when I get models from others having this sort of problem, I set the units to the highest precision and then use the Text tool to add coordinate labels to vertices in the drawing. Most of the time when there's a problem with getting proper faces, it is due to variations in the Z value. You might check that.

[pbacot]

I know whereof you speak. It's a pain. I don't use the edges I import in plan. I draw over them. Even then the dwg import can somehow throw things off. It's as if they are ortho edges, but not quite, and faces come and go. Better luck lately. Drawing over, snapping to intersections seems to be OK. But I rarely do the fill walls and extrude method you are showing anymore. I build the house as a box and add detail from there.

[HornOxx]

Hi Niko
I know what you're describing and this is terribly annoying indeed
I agree with Dave that it often has to do with the Z-values of the used DWG files, at least in my cases.
I just can offer the following wokflow which works fine for me: To eliminate this z-value-thing, I import a DWG into SkUp. Once I see the drawing in SkUp, I export this drawing from SkUp as a new 2D DWG file - for example, a floor plan as a top view without perspective. This new DWG will have no different Z-values anymore and will work as a template then...

[harnstein]

Thanks for sharing your workflows - and your solidarity!
This is really a bummer, one of the most hated things in SU (for me).

Whenever its possible I do like to redraw the whole plan, or better, the parts which are relevant for a 3D model depending on detail level by myself.
This gives me better control over grouping and layers - and in many cases there are some little unprecise parts in the drawing which messes up everthing in the end. Best if you have repeating elements and if you draw them by yourself you get a perfect result.

But: in some cases like this its just impossible (or e.g. if you have some complex freeform things or logo or whatever you just cant redraw (easily / properly)). I have to reconstruct a theater of Hans Sharoun. And if you know his philhamony in Berlin, Germany I hope you feel with me He could have left some things simple, at least where you dont see it.

Anyway, thats the task, and for sure it's an interesting one.

That's why, Dave, your tip is a good one but I cant use it here. There are millions of vertices.

It's odd as you even dont know what you import even though it looks OK in other softwares. Sometimes parts of the plan are at other levels even though they are not in the software they come from. Or you change some export filetype and you get something different (scale, parts, whatever). That's why your tip, HornOxx (nice name), is a good one too.

The very main problem is SU itself. Because it just gets weird handleing (big) plans. Because even if EVERYTHING is OK, same plane, closed face, all perfect - it's not working. Guess it's some code thing. It just can't. That's why I called it "teach" SU what's the face, and then SU is like "Ah, now I get it." ..and forgets its again a minute after and messes everything up again.

Seems like I have to deal with it as is. Go through this pain, get myself some of those balls you can hang from your desk (called niceballs, on kickstarter, WHY?) and push through. Maybe I should add those balls as a solution for this problem.

So, thanks guys for your support!
If you search for me, you'll find me here, closing faces.

Niko

[Box]

Could you attach a .dwg that you have these issues with so people can check if they have a better solution for you.

[Dave R]

I wasn't suggesting that you check every vertex. Spot checking a few would like show if this is the problem.

This sort of thing isn't the fault of SketchUp but rather the author of the DWG and/or the program from which the DWG was made. It isn't unusual to have gaps where lines should meet or overruns. If you aren't concerned about creating faces which is often the case in 2D DWGs, there's no need to worry about those kinds of issues. The drawings work fine. But these things cause problems when you do need closed loops of co-planar edges in order to create faces.

[harnstein]

Thanks again,

@Dave: Ah, sorry, now I got it. I'll keep that in mind for future imports!

@Box: Thanks for that offer, normally I can import plans properly after a little try and error. I guess I shouldnt post those plans as they're not created by me and therefor might be confidential.

Btw. great to see you guys are still around here

As Dave said, there are too many different softwares and export variations out there so you're never sure what you'll get (only if you've worked with a client before - and even then). If it's really not working you'll sometimes have to ask the client for different file variations.

Actually in this case I got results with various processes in Autocad eg. the following actions: open dwg - command: flatten - command: units - command: setvar > insunits > 0 - command: qselect > all text - express tools: explode text

Got the right scale in SU, text was readable and after some cleanup I could use those plans.

Further workflow: grouped each floorplan, then selected only the relevant visible layer(s) and grouped them as well. Used Thomas' cleanup tools on those elements. After using make faces plugin and some cleanup by hand I got pretty well working results.

IF there are some odd problems where the shouldnt be any (like the screenshot I posted above), I could sometimes solve them by eg. selecting the face when it is still working, copying it into memory, getting rid of that geometry, closing a larger area face -> and pasting that geometry back in. Sometimes works as properly intersected geo then.

Overall I get along with it like that this time. Still the model ist pretty complex and it takes a lot of investigation. Maybe I'll post a shot of the final model here after.

Have a good day guys!

[slbaumgartner]

I sympathize!

The main problem is that the importance of tiny glitches in a model varies depending on the originating software and how the modeler wanted to use the model. The worst case is when the originator is thinking like a 2D draftsman, not a precision 3D geometry modeler. That is, if a visible or printed drawing is the desired output, you draw lines from here to there so that they look good but don't really care about minuscule glitches because they are invisible on the output. You don't care about z-axis drift because everything flattens out when printed anyway. If you are drawing outlines, not faces, who cares about invisible gaps? Even if the output is going to a CNC machine, CNC only cares about tool paths. A gap that is smaller than the cutter won't affect the machined product.

At one point I tried to create an importer for vector PDF and gave it up as hopeless. To a large degree this was because there are fundamental differences between how PDF creates a model and SketchUp's geometry database, but also it was because nearly every sample file I tested had numerous places where the thickness of PDF lines hid the fact that their endpoints did not actually coincide or that edges weren't actually collinear or parallel.

[valerostudio]

Yep, we've all been there and it is painful. Usually this happens with imports from AutoCAD. I usually run ThomThom's Flatten script in his Architect Tools set, just to make sure everything is on Z=0. Then I use S4U's Make Face script. Most of the time this works, but you might need to find little unconnected gaps, in this case, try ThomThom's Edge Tools.