Multiple faces driving me crazy!
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@hellnbak said:
... I was just hoping that someone had a good tip on how to avoid creating the faces in the first place. Actually I wasn't very hopeful, but figured it was worth a shot. ......
I haven't seen any example model yet, showing this very issue. There's no guarantee whatsoever that I'll be able to come up with an answer but I wasn't joking in offering to seriously look into it.
Well, it's up to you. -
Sorry. My models are too large to attach to the forum, so I've attached just a hood from one. I do remember that it, like most other things I've worked on, enlarged my vocabulary as far as multiple faces when I was making it, adding faces and subdividing them. That's not to say that it will do the same for you, maybe you've got that one in a million copies of SU that is problem-free. If so, I'll buy your computer, price is no object
How 'bout just the hard drive?By the way, you didn't answer my question - have you really never encountered multiple faces in any of your models? Even just a double face?
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Here's a sample of mine. Draw lines on the faces in this model and you'll find that SketchUp starts adding extra faces where there already are faces.
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@thomthom said:
Here's a sample of mine. Draw lines on the faces in this model and you'll find that SketchUp starts adding extra faces where there already are faces.
Well, I drew lines all over it, subdivided it, kicked it, screamed at it and caressed it, and wouldn't you know it - not a single extra face
Actually that was one reason I was reluctant to upload a model, I figured that Murphy's law would guarantee that the problem wouldn't show itself when you wanted it to. -
@hellnbak said:
@thomthom said:
Here's a sample of mine. Draw lines on the faces in this model and you'll find that SketchUp starts adding extra faces where there already are faces.
Well, I drew lines all over it, subdivided it, kicked it, screamed at it and caressed it, and wouldn't you know it - not a single extra face
Actually that was one reason I was reluctant to upload a model, I figured that Murphy's law would guarantee that the problem wouldn't show itself when you wanted it to.Before drawing a line:
drag a selection rectangle right-to-left over one of the large faces. It should select two - the one you see and the one on the back.
Now draw some lines criss-crossing the large face, make the selection rectangle again over one of the faces, it now selects more than two faces.
Happens every time. -
Yup, that did it. I'm assuming this model is made up of just normal faces, so what does using the select tool first, and specifically right to left, have to do with it. And more importantly, is there maybe something in this that could help me with avoiding the double faces, something I may be doing that is causing them? I don't see what it could be, but I'm still a little hopeful.
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I did managed to get the extra faces as suggested - there are two extra pairs plus the original [3 'overlays'].
If occurs if I draw a diagonal on the large face with the tiny 'spike' at its base.Another interesting observation...
IF I draw the diagonal so that its end point is less in the Z and greater in the Y [than the start] I get NO extra faces... BUT if I draw the same diagonal on the face with its start and end points transposed, OR I make the other diagonal [in either direction] then there are extra faces added...Just weird...
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@hellnbak said:
Yup, that did it. I'm assuming this model is made up of just normal faces, so what does using the select tool first, and specifically right to left, have to do with it.
Just a method of counting the number of overlapping faces.
If one of the faces had a different material you'd see z-fighting. -
@thomthom said:
Here's a sample of mine. Draw lines on the faces in this model and you'll find that SketchUp starts adding extra faces where there already are faces.
Hi Thomas, I see the issue. And it's not difficult to see where it originates from. Bad geometry. Unfortunately you present a model with faces that aren't flat to begin with. There are latent two faces to begin with for each large side face, although SU cannot show the diagonal. Most likely because it's waywithin tolerance.
Concider one face, the one that looks like a rectangle.
Measuring differences perpenducular to the face with the 'Tape Measure' tool isn't helping much after self aligning axes (right click > Align Axes) to the face. Maybe SU gets confused because of whatever?
So align the axes manually and forget the 'Tape Measure' tool but...- ad a 10mm line on the face, perpendicular to the face.
- select the face and the 10mm line.
- select the 'Scale' tool and scale both face and 10mm line up by 100 and again by 100.
The result is a twisted face without a (hidden) diagonal. Apply 'Fix Problems' to see the change happening. The geometry was bad to begin with.
(I wonder if it has anything to do with having length snapping off. I have it on all the time although small)
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@wo3dan said:
....So align the axes manually......
By that I mean: use the base edge for red and the hinge edge for green.
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@wo3dan said:
(I wonder if it has anything to do with having length snapping off. I have it on all the time although small)
hmm... Maybe..?
I was wondering if it had something to do with minor deviances occurring when you transform entities.
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@wo3dan said:
Yes, that's what I said.
@hellnbak said:...You really need to buy a lottery ticket
I'd rather have that model of yours instead of the ticket.
For I also never win with lotteries.
Hi hellnbak, you're right, Murphy strikes again.
I checked your model. No extra faces.
And when I try to divede (manually) trianglular faces notting odd happens.
b.t.w. I did answer your question. I may have exaggerated a bit but then it must have been quite some time ago. As soon as some irragularity happens I surge till I can get rid of it.
There seldom seems to be something going wrong.
Do you have 'length snapping' on? I do. And sometimes I can even see that minor differences are overcome by SU snapping to nearby geometry. I checked Thomas's geometry which was incorrect to start with.My PC is over 5 years old and in bad shape. SU is good though. Still interested?
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Checking the lengths of the edges in the face - each parallel set:
` 53.9597217259116
53.960193935468499.2125910192198
99.2125910458392`
So while SketchUp will colour them parallel with the model axis - they are yet different enough to cause problems.
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This is turning into an episode of CSI. But I'm following with interest
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hello i have got the same problem in my model, but when i move surface from corner point to center of the origin and it is solved. But what's the relation between them i can not understand and also if it possible to works for all models.
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I know this is an old post, but this is exactly the same problem that I have on nearly any model that I import from an STL. It takes hours to fix and because of it I am seriously ready to ditch SU for Fusion.
It's NOT caused from bad geometry practices so don't even say it! I can have a hole in the mesh and literally draw 1 line to close it and it will create many extra faces. I have had up to 15 extra faces on top of each other! This is a serious bug and I cannot believe it is still going on many years later!
Most of the holes are caused when I import an STL into SU like I did with the example file that I am including. I have already painstakingly closed each hole up manually since I have yet to find an extension that can do this automatically. I bet I spend 50% of my total time in SU just fixing holes and deleting extra faces, this is simply unacceptable.
Please help if you know what is going on and how to fix it.
Thanks!
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