something to keep in mind too is that SW does not do all things well. there were many a time that i had to delete faces and use surface lofts/sweeps, etc to hand what looked like simple fillets.

I can, however, understand the frustration at the "...PARASOLID..." elites and I had to swear many a time at them.

Side note - in the past I also had to use a local Rhino guy to add fillets for me on models in which history was not important (SW being a history/feature based model for those that do not know this already).

I have wondered how simple the concepts are on fillets when looking at them from the mathematical perspective.

Hi mshideler,

> I have wondered how simple the concepts are on
> fillets when looking at them from the mathematical
> perspective.

Well, there are several steps involved, like creating offset surfaces, intersecting those offset surfaces to get sort of guide rails for the fillets, then building fillet surfaces, and extending and intersecting those fillet surfaces.

There are potentially tricky parts to each of those stages.

But the really tricky part is constructing corner junctures where many fillets are trying to meet up (like where you have several edges coming together into a shared common point). There isn't really a single mathematical solution for that, it's basically handled by a lot of special case code that sorts things out into different categories of junctures and knows how to handle each of those special cases.

The filleting engines that work better tend to have had a lot more time invested in doing a whole bunch of those different kinds of cases.

But that's why it's difficult to make a really robust filleter, it's not just guided by one single code path that can just be refined.

- Michael

>>Otherwise if you do want to make it in MoI you would instead need to use some surface modeling tools to build it, something like trim >>away some areas and then build a sweep in there instead of trying to use fillet. Let me know if you want to try that and I will try to >>help you with it, but really if you have another solid modeling system available to you, it's easiest to export over to it and do the fillet >>there.

As someone who has encountered similar problems with the fillet function, I can highly recommend using the "sweep" function. In many ways, you get better control over the final shape and how it relates to the various surfaces.

Give it a try instead of expecting a one click solution!

Cheers,

Chris