SketchUp Pro 2018 is not recognizing the “closed” polygons as distinct boundaries

Greetings, I am back again for additional guidance.
Following my last visit some weeks back, I received much helpful advice from several skilled folks, then I went away and tried to apply what I learned. Seems I may have slid backward.

I started a new SU 2-D floor plan drawing, keeping it very simple.
Turned off length snapping, but left ‘on’ angle snap to 15 degrees.
Layed in a ground plane canvas tied to the origin with Z=0.
Then I created a simple floor plan drawing striving to keep all lines and shapes on the ground plane as recommended. Using only Layer 0.

Drawing was accomplished in great part using the tape measure to layout grids and then drew using the line tool primarily, and the rectangle tool some. I used the arrow keys to draw lines in the red/green directions, taking care to hit corners and stop on lines. Used the rectangle tool minimally, but when I did inferencing was used to place the rectangle.

Rectangles are not being recognized as closed polygons with distinct boundaries. No distinct plane is created within the closed rectangle.

Dbl-Click about anywhere and you will see an unusual set of elements highlighted in blue. Filling a shape with a new color will likely produce unexpected results.

I have looked unsuccessfully for short lines extending into rectangles, gaps and stray bits.

Also, I should note that in an email exchange with an experienced forum member they noted:

I spent an hour or so trying to understand why SketchUp is not recognizing the “closed” polygons as distinct boundaries. I failed. I suspect that some of the points are very very slightly off of the Z=0 ground plane. But I can’t find it.

I scaled up the geometry in the vertical dimension by a factor of millions, and set the Model Info window’s Format to Decimal, and Precision to the maximum (0.000000" or something like that). Then I used SketchUp’s Text tool to click on various end points and drag out to have SketchUp display the 3D coordinates of the chosen point (which is the default text for the tool, when on an end-point). Everywhere I looked, the third dimension was 0.000000". Even so, there must be a discrepancy somewhere.

You can get a hint of this by orbiting the camera away from the straight down view. When looking obliquely, various portions of the floor will flicker as you orbit around. This is called “Z-fighting” in computer graphics, which means there are two surfaces at about the same visual depth from the camera, and the rendering engine is flipping back and forth drawing one or the other as the view changes slightly. Deleting those various flickering faces cleans up the model but does not “heal” the fact that the ground plane does not seem to be touching all edges.
Suggestions and observations welcomed. Model is attached.
Thanks, HOME May2018v2.skp (215.6 KB)


There are some very odd irregularities which are probably caused by tiny inaccuracies, possibly caused by your workflow, but also some know idiosyncrasies of the software itself.

Try using the rectangle tool more and the line tool less.
I can make your plan work in a variety of ways but it gets a bit complex to explain and takes some time.
Whereas It took me only a few minutes to trace over your model using the rectangle tool for all but the angled lines, and it is all working correctly.

HOME May2018v2Box.skp (250.9 KB)

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Thanks for looking at it and commenting. Hmmm. Workflow and known idiosyncrasies. Where to start?

In past years I have always used the rectangle tool heavily. For this drawing, I was actually taking the advice of one of the forum members, just to see how well it would work for me, since it was a small simple drawing. The result was as you say, some very odd irregularities. I see the irregularities, but I do not know how they occurred.

Regarding workflow: I have been using SketchUp casually, on and off since version 8, primarily for my own entertainment. About four years ago I actually did a small tenant development job using Layout and SketchUp. Layout caused me a bit of head banging, but it all came together.

So, I have to ask. When you noted “known idiosyncrasies”… In your experience with SU Pro 2018, is it “highly idiosyncratic” compared to past versions? I ask because I have not had so many frustrating issues with such simple drawings.

Lastly, please share, when you traced over my model, did you import a snapshot of my model as a jpeg and draw over the top?

Here’s a thread from 3 years ago on the subject and it references much older discussions on the subject.
I don’t think it is worse in 2018, but certainly not better.

No, as you see in the model I attached, I made all of your model a group and simply drew a rectangle on that and traced everything in situ. But it could have been a jpg or just from measurements. I rarely use guides.

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I suspect it has to do with the order of creating your geometry, whether with the ‘Line’ tool or with the ‘Rectangle’ tool. It’s just the order of adding connected loops with any tool.
See attached image and the differences in the three examples that result in seemingly the same geometry. They are all different in how faces are divided.
From left to right: bad > a little better > and okay.

The numbers indicate the order of creating faces with either rectangles or the line tool. That doesn’t matter.
The three similar rows show how you can select faces.
Look at the profiles in example 1 and the extra odd face selection in example two. Although the profiles are gone, you can’t select the inner face. It selects the top right rectangular face.

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I am the “experienced” (cough! hack! :slight_smile: ) forum user that Will has been corresponding with, and who wrote the quoted paragraphs. I could clean up the model by deleting the superfluous faces (shown by Z-fighting in most cases), re-tracing some edges, or in some case deleting some edges and re-drawing them.

I’m wondering if Steve @slbaumgartner might be able to apply his high-decimal-precision version of SketchUp’s Text tool to a few of the end points and see if there are any non-planar coordinates.

Actually, there’s no special version, just set units to decimal with max precision and you’ve got it!

Really? SketchUp (2016, 2018) shows me six digits to the right of the decimal point, and I could swear (I know, I shouldn’t swear) that I’ve seen some screen captures from you with 10 or 12 digits.

I doubt if there are any vertices out of plane.

Add a short vertical edge to the geometry (to allow you to scale in vertical direction)
Select all > scale vertical by x100 (using the now available middle grip due to the little edge)
Inspect the exaggerated vertical differences of vertices. There appear to be none. All vertices are in one plane (except the top one of the added edge)

Yep, in fact I did that with scale factors up to a million, and the native Text tool showed no deviations from plane out to six decimal digits. The fact that quite a number of the “spaces” that look to be closed don’t form full faces when drawing diagonals has me confused, and suspecting slight non-planarity. I suppose it could instead be due to SketchUp’s vagaries with forming faces.

Box, That thread from 3 years ago is great. I’m going to read it more than once I can tell.

i deleted the outer frame and just ran the “make face” over it all. Almost everything tied together except for a view overlapping face with z fighting. A number of reversed faces. Some lines that needed retracing. So I don’t think anything was offHOME May2018v2a.skp (226.6 KB)

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My word. With your examples in mind, it seems at first blush that (as an example) drawing a complex two story 3-dimensional model of a house with textures, materials, colors, shadows, profiled edges to show indication of depth, section cuts etc etc, is “totally dependent” on being able to create each shape in the correct order so as not to end up with a chaotic bundle of undesirable anomalies. I cannot believe that perfectly ordered drawings are being accomplished by the architects out there who use SU in their practices. Yet, the drawings are being produced.

This leads me to believe that there is a methodology for adjusting the the drawing to deal with the characteristics of the program. (Should I call it a bug??) And, the methodology cannot be hugely time consuming or Architects running a business would not be able to afford to use the program.

In my view, the architectural design process requires a lot of jumping around, adjusting geometry, looking at form relationships, adding and deleting and adding again. The havoc this would create with one’s drawing relative to your example would I think be great. The drawing I submitted for your review was “A Mess” form the perspective of creating a “well drawn” SketchUp model. And it was small and not complex.
What you all think?

I am visualizing that red half-sphere shaped button that says EASY on top in big letters. You have see those right?
It appears that “make face” pretty much fixed most all the problems in quick order.
Please tell me where “make face” is located.
Much Thanks,

It’s in the extension wharehouse, or sketchucation. “s4uMakeface”

I’m not sure I understand how it works, but I have often found it handy to fix what you are up against.
While it got most of it sorted out, there were as I mention a few lines that needed retracing and the reversed face (easy to see in monochrome view).

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Thanks for the tip on the extension (s4uMakeface). I am wondering, do you use this extension primarily on drawings that are 2-D, or do you find it just as useful on 3-D models?

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It’s kind of the same thing within sketchup? While sketchup can be used as a 2D application (although Layout is the 2D companion) that would be under utilizing its full potential. Most all geometry begins in sketchup with 2D shapes that get extruded into 3D, that seems to be the underlying strength of it. So the use of the plugin for me is useful at the primary stages of the 2D drawing prior to 3D if there are any issues. Most of the time if you are drawing “correctly” these lost faces don’t occur. However, as the example in the video for the plugin shows, that when lines are inadvertently broken, the faces don’t form as expected. and so need to be made a face again. The other time this plugin comes in handy is after importing DWG 2D plans, as they will most often need to be treated to form faces. If you are only in need of a line drawing, the faces may not even matter as it wouldn’t be apparent if they exist or not, unless those areas need to carry a different color/texture…or be able to be extruded!

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