here is my problem,

i am trying to subtract the red shape from the blue shape to leave the red shape protruding from the blue shape. the red shape was made with 2 cubes, twisted in opposite directions .on my first attempt i used boolean union on the two cubes before subtracting and for my second attempt i left them as two separate pieces. both attempt showed up with the error “non manifold edges caused boolean differnce to fail” or something. can anyone help?

the red geometry appears to have self intersections. If these are two objects, try to split each of it using the blue shape, then clear all connections up manually so there are no more self intersection. If this does not work, please post a file with both shapes.

c.

Hello - the blue object has extra internal surfaces that need to be removed. There are two coincident faces between the dome and the cylinder below it - Use ExtractSrf (in a wireframe view is best) and then delete these surfaces. Then Explode and Join the whole remaining domed part. Then things should work better.

-Pascal

that worked great!

thanks a lot