Problem model

Here’s a conundrum, to me anyway.

I attach a simple model which forms the internal walls in a model of mine. But it clearly has some gremlins lurking within.

You will see that one space in the centre has a “ceiling” and no amount of drawing over the lines will allow me to isolate and delete it. Equally, the base of the wall is not closed. again, nothing I try to do will close it. Then try a horizontal section. Everything disappears.

I guess this might be a case where it is simplest to give up and start again, but if there is a way of identifying what is wrong, I’d like to know how to do that and then how to correct it. I find that this sort of thing happens when you have done a lot of editing, as I have with this.

Internal walls.skp (140.3 KB)

Looks like you’ve got things out of plane somehow. All the z-values should be the same in the coordinates for the various corners but they aren’t. The bottom has the same issue.

There’s also a micro edge in the corner over the door.

Wow, off by tiny fractions of a mm! No wonder I couldn’t see it. I have my settings down to the nearest mm so I don’t see all those numbers after the decimal point.

I have just remodelled it more or less from scratch and there is no problem. So maybe that just has to be the answer rather than spend a long time looking for faults.

I just redid your model and had no problem maintaining the same Z-value at the top of the walls. I wonder how you went about doing it.

Internal walls.skp (141.9 KB)

I’m really not sure. It doesn’t often happen as I can usually find the problem. With this I have done a lot of moving walls and cutting new doorways. Sometimes, as here, the problem gets highlighted if you invoke section fill and some parts of the walls don’t get filled. That is usually because there is a face missing somewhere, but the problem here was beyond that.

I suggest seeing the display precision as high as it will go. Seeing a string of zeroes where expected is very reassuring to me.


I thought that SU didn’t really work well at very small scale (hence the need for the Dave Method). It’s a bit rum that it should throw a wobbly for such tiny differences!

That has nothing to do with setting Display Precision high.

Setting the Display Precision high allows you to see discrepancies in dimensions. You wouldn’t have seen the differences in those Z-values I showed if I’d left the precision set as you had it.

Endpoints of edges can be located with extreme precision (millionth of an inch, say, at least near the world origin) and SketchUp will not normally alter their location. What causes trouble (to my way of understanding) is when two endpoints are located fairly close to each other. In such cases, SketchUp wants to merge them.

A very quick test is to intersect the geometry with itself, if it remains clean it is fixable, if it turns into a mess of triangle, give up and start over.
Off axis


If you have Length Snapping turned on (checkbox on the Model Info>Units dialog), you should turn it off. For some perverse reason it is turned on in all the default templates.