Where to report a "Group by Slice" issue

Hello SketchUp Community,
I am wondering where or if this is the best place to report a bug. When creating a Group from Slice of a Section cut, the group is not a true 2D slice. It creates an approximate zero in one of the axis. This is an issue that came about, or that I first noticed, in 2019 Sketchup. I downloaded the current 2021-1.2 version today and this is one of the first things that I checked to see if it had been repaired, unfortunately not the case. This was not an issue back in Sketchup 2016. Hoping this could be addressed in the next version that comes out. Has anyone else had this issue? Is there something in my model that can be causing this? We use a lot of dynamic components and many of those having plenty of attributes.
Edit: A way around this has been to add size attributes to the group and attempt to zero out the approximately zero LenZ. Still end up receiving hidden geometry triangulations when making faces of this group. I usually end up needing to do a 2d export of the group by slice to get it to be a true 2D entity.
Besides this I am stoked on this new version of Sketchup!
Wishing all the best,

This is as good a place as any. Share an example .skp file in which this occurs.

Thanks Dave! My company is a little sensitive about sharing our “standard,” or else id love to share the .skp. I’m sure they wouldn’t mind sharing a file of the group by slice if this would help? I’m diving into it a little more so that I can send more info to help trouble shoot.

I’m not 100% sure that the problem I’m chasing is the same as what @andr3w44 has reported, but it’s the closest thing I can find in the community discussions, so allow me to chime in and describe what I did to fix the problem.

I discovered what I would consider to be an anomaly in the use of section planes when examining the output of the Create Group from Slice command. What I found was that in some of my models, the geometry in the group that gets created from a slice from an active section plane is not all on the same plane! @andr3w44 might be able to comment on whether this is what he meant when he described that the resultant group “is not a true 2D slice”. Whereas Andrew experienced deviations from the plane that are approximately zero, I’ve experienced deviations of as much as 1/4".

To investigate this phenomenon, I created a section plane through one of my problem components and looked at it from a bunch of angles and determined that the section “plane” doesn’t appear to intersect the model all in the same plane! (It should, shouldn’t it?) I’ve attached a .skp file which shows a non-planar section cut. Zoom in on the section plane and check it out to see that the intersect lines don’t line up with the section plane. To the right of the component, I’ve included a group that was produced with the Create Group from Slice command on that section plane. Please feel free to experiment with it to see the phenomenon in action.

The original component was made in version 17. It is a dynamic IGU for a set of windows I created. It probably underwent a lot of fiddles and transformations before I used it, so I have not tried to recreate any new objects from scratch that exhibit the same behaviour.

I have discovered a way to fix it, however. It seems that if I go through the objects and scale the definition of each one, this strange behaviour of section planes goes away, and the slices are once again planar.

I suspect the strange effect is somehow an artefact of all the gyrations I must have gone through to create my component, and I suppose it should have been obvious (?) that I should rescale all my object definitions at some point in my workflow. However, I’m never quite sure when I need to do that and when I don’t (which is something I’d love to have a tutorial on). Regardless, I feel that the strange behaviour I’ve experienced must be considered a bug. I think that the geometry created by a section plane slice ought to all exist on the same plane no matter how messed up the original geometry is.

I hope that the SketchUp engineers can learn something useful from this, and that other users with the same problem will be able to fix their objects and carry on modelling.

Section Plane problem.skp (48.6 KB)

I have this issue when creating sections of our houses! I get overlapping lines but they do not merge together because they seem to be an “approx. zero” I spend most of my time trying to redraw lines and as I’m doing so, sketchup creates multiple faces sharing the same plane!

You likely get this from separated groups.

I explode all my line work down to one layer and I get this issue

If there was separate groups/components within the section and you explode them, then the lines / faces separating those groups are still there. You would have to go in and edit them.

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Oh, I didn’t realize. I’ll have to hunt down a better method then! Thank you!
By the way, Nick, We’re working with Amy on a project this year, it’s gonna be a fun one!

My sister in law?

Search the “Donley Method”.

Yes sir.
Thanks, I’ll check it out!

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Tell her in your best NE accent that I’m wicked pumped your drawring an awesome project with her!

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:laughing: will do.

Thanks Nick,
Donely method is close to what i need but I’m still in a workflow of texturing my sections to show insulated envelopes etc. I’ll keep toying around and come up with a solution.

What scale are your sections?

If you have an assembly method, there is no need to show insulation in 1/4” scale drawings.

We are using 1/2" sections

I used to do 3/4” wall sections. I found that using building sections at 1/4” that key 3D details and assemblies provided more information for the builder. The 1/4” sections allow me to capture every plate height of the structure and help determine the detailing/assembly requirements while still remaining a simple fill.

So far the best solution I’ve seen for what you want to achieve is “Skalp”.

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