How does the Geometry.DoesIntersect node work?

Hi, I am curious about how the Geometry.DoesIntersect node work? In this model below, the slab does not intersect the columns and beams actually, but the Geometry.DoesIntersect node detected the results as all true, which is not the fact. Does anyone know the principles behind this node? Thanks!



dynamo.dyn (38.4 KB)

You’re confusing intersection with a clash.

I am sitting on a chair, but I do not clash with the chair as the chair has it’s space and I have mine (we can argue about the molecular bond between my backside and the chair created by my tendency to not walk away from work at a later date). The intersection between me and the chair is a surface, but it does not have a volume. DoesIntersect will return true if there is as much as a point of overlap (a pin stood on end on my chair perhaps), and it will also return true if the object is entirely inside the other (say the sandwich I ate for lunch). If you’re concerned with construction clashes, test the actual geometry intersection (Geometry.Intersect) when objects return ‘true’ when testing for DoesIntersect, and filter out objects which don’t create a volumetric solid.

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Thanks @JacobSmall for your detailed explaination!

By “DoesIntersect will return true if there is as much as a point of overlap (a pin stood on end on my chair perhaps)”, do you mean if two elements are in contact, the DoesIntersection node will return true for them?

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Yep

Thanks!

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