Odd result with very basic Boolean Union

Hi all,
I’m trying to Union two “roofs.”

This was built with two linear edge extrusions to which OffsetSrf was used to add thickness, then a boolean union was attempted to the two objects.

It seems to work in that it creates a single object, but the faces of the edge seem to remain separately selectable and don’t have the geometry I’d expect. Not sure if I’m doing something wrong.

roof-boolean.3dm (89.2 KB)

Any thoughts?



Since both front faces are coplanar, you can simply use MergeAllCoplanarFaces to clean the model up.

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Thanks! When I did this in the original, the two non-connected faces were still present. I am still getting used to how/when geometry disappears.

The geometry still isn’t as I expected though (what I need are show with blue dashes) - what’s the best way to get to this result? I’m not sure how to either “regenerate” the edge face or grab the diagonal line to move it to the corners.

The diagonal line on the faces does not show an edge, but an isocurve! They are primarily shown as visual aids, I believe.

If you want to insert an edge, where you’ve drawn the blue, dotted line, you can use SplitFace.

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Much better. Turned them off for now :slight_smile: