Boolean Difference removes wrong part whichever half I select

there is no way if indicating to Rhino which part is to be removed in Boolean Difference.

I have a simple block and cutting surface yet in first of command, select item to subtract from,

first attempt select the bit I want removed, it removes the other main part.

try again, select this time the main part, it still removes the main part.

BooleanDifference removal indicator need.3dm (57.9 KB)

Actually, there are several ways, because it’s the direction of surface that decides which side is cut:
1: Check the direction of the cutting surface using Dir before running boolean - and flip it if needed
2: Use a display mode with backfaces set to a specific colour (to easily identify what’s front and back) - and flip if needed
3: Use booleansplit instead and delete the surplus part yourself

Basic stuff, really.

HTH, Jakob

Also, You can try it with the boolean2objects command. Then you can select which part you want to remove and/or keep.


/\ Matthijs

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