I have a part from a vendor that came to us via a stp file. The part is a component of a seat assembly. Its the seat bottom. I want to thicken just the top surface. I copied the top surface, then stitched the 6 copied surfaces together. I then tried to thicken it and I got an error. So I stepped back and tried the thicken on just the two rear surfaces and it worked. Apparently the front 4 surfaces are not "attached" to the two rear surfaces. To me, this seems like a simple fix. Just get the mating edges to match up and it will work. The thing is, I can not figure out how to get the misaligned, copied surfaces to join. I have tried a number of different things. So, I am hoping someone can guide me in solving this issue. I think if i can work thru this exercise it will help me work thru other issues.
so seeing the results we must assume that the mathematics behind is not 100% the same.
But again this only can be solved by the developers only.
Maybe it's worth to send it as PR to GTAC.