Issue creating faces for audio software


Hi Guys and Girls,

Excuse me if this a simple question but I seem to be having issues creating faces within my model. I’ve created a stadium from given measurements but barely any of the surfaces have faces. I’ve researched about keeping everything coplanar and also using colour by axis but cannot see where I am going wrong. Any explanations or help in simpleton language would be very appreciated!

Thanks a lot


Here is a screenshot of the design


It would be easier to identify the exact issue with the SKP file but try drawing diagonals between corners. If you get two triangular faces, it is likely the four corners of the trapezoids are not coplanar. Try erasing the diagonal. Does the face remain?

How did you get the edges into SketchUp? Did you draw them manually or import from some other file?


I’ll try drawing diagonally now, 2 minutes. All lines have been drawn, nothing imported. Thanks!


When drawn diagonally the faces appear, but when the line is removed then the face goes with it


So then the four points are not coplanar. And it’s really two faces that go when you delete the diagonal edge.


Toulon Simple w: faces~.skp (245.4 KB)

Here is the file also! Thanks


I think the problem has been identified now. So the question is, do those trapezoids need to be single faces for your application or can you manage with them divided into two triangles? If you need single faces, you’ll have to rework the positions of the corners.

Are the horizontal curves all of constant radius and concentric in plan view?


Right okay, how is it possible for me to create these points to be co planar as they are based around a ‘circular’ edge? Thanks for your help, again apologies for my incompetence!


You could draw a cross section at one end of the arc and sweep it with Follow Me. I’ll make a quick example. Give me a few minutes.


Even though the horizontal curves were built using the 2 point arc tool, all curves should be in relation to an original centre. For my application single faces would be easier for the processing software, but with my SU skills I believe 2 faces may be easier. Also the more complicated tiered seating, tier 1 worked fine as a face but the second tier didn’t. Again I presume a coplanar issue, but trickier to split into faces.


See if this helps.

From foreground to background

Draw the cross section of the seating area and the curve at its base. The cross section is the profile and the curve at its base is the path for Follow Me.

Select the path, get Follow Me and click on the profile face. After the extrusion is made, the faces may appear blue. That would indicate they are reversed. Select them, right click and choose Reverse Faces.

If you want the lines between faces to show, select all of the geometry, right click and choose Soften/Smooth. Set the slider to the left.

You can add the tunnels afterward if they are needed.


Well that could of saved me a pain-stakingly slow evening! I shall try that now in a new project. Dave, thanks so much for your help, really appreciated. Have a good new year.


Look on the bright side. If you hadn’t been doing that, you’d have been park in front of the television. :smiley:

Happy New Year to you, too.


The line tool is one of the most important tools in SketchUp, you can’t practice enough with it :wink:


It’s worth noting that if you show the hidden geometry in Dave ’ s construction you’ll see it is made up of triangles the same way as your painstaking construction.


Why triangles?


I’m on my phone so can’t show what I mean. But I assume the curve is such that the facets are split. I could be wrong.


Only rectangles in this case…


Actually it’s impossible for them to be rectangles.
But now I’m being picky.