Best Of

https://www.onshape.com/en/blog/thickness-analysis

if you're on the standard plan, sadly this is not available. :-( (i.m.h.o. it should be, this is standard CAD analsysis stuff). In that case there's a custom feature by @MichaelPascoe :

https://cad.onshape.com/documents/55e98155dca4ba4e8049a18d/w/dbf02fb86aafef13f08be126/e/67100c66e805cdf37822750a?renderMode=0&tangentEdgeStyle=1&uiState=684ff1f95854d0479d7932da

Coming to Onshape from Solidworks and Fusion 360 there was a gap in the feature set that I was missing from both of these tools. In Solidworks the feature was called Intersect and in Fusion the feature is called Boundary Fill. In each of these softwares the feature does basically the same thing, which is enable disgustingly lazy modeling practices where you can kitbash parts together keeping the functional bits of part A and part B and discard the leftovers in one go. I couldn't go on living without this jackhammer of a tool in my belt so I went ahead and developed my own implementation in Featurescript. I present to you: Better Than Boolean.

It works by decomposing input bodies into their overlapping regions and allows you to select which chunks of Venn Diagrammed part you'd like to reconstitute into a single manifold body, throwing away the rest.

Okay that's not that impressive, you could do that by selecting regions of sketch and just not extruding the bits you didn't want. But what if you wanted to make a manifold body?

For example let's say I want to 3d print a garden hose manifold and I wanted not to waste time modeling threads. Of course I'd derive a single part into a studio to simplify the modeling process. But I'd also have to define a cutting tool to remove geometry for the water to pass through, and I'd have to trim parts off of my tool body to make sure the internal bits don't interfere with each other or the manifold body. That's a lot of work, and I'm lazy.

Before:

After:

Now if you're familiar with either of those implementations of tools I mentioned before you'll be aware that they also allow enclosing of regions via planes and surfaces. This is not yet supported by this tool, but is something I might add in the future. Would probably require a complete refactor of the decomposition logic which is currently being done purely by bounding box checks, evCollision, and a whole mess of boolean operations under the hood. I'm putting this out there in the current state because my core use-case is greebling parts together and not surfacing operations. One day when I figure out how to do a plane sweep algorithm I might rework the core logic under the hood to add the surface and plane functionality.