Hi Dave,

> The only problem I've had with the mesher so far has been
> in a couple of cases where, with "ngons" turned on, its created
> an ngon that modo doesn't handle correctly.

Yeah, I've seen some occasional cases where Modo's n-gon triangulator has problems generating its own triangulation from an n-gon, particularly if it is a complex n-gon which has numerous 90 degree corners in it. Probably if you try to manually trace such n-gons with a new polygon in Modo, you'll see that it is a Modo bug where that shape is just not handled right.

Until MoI was around, there basically was not really any way to easily get an enormous number of complex n-gons generated, so some programs still have some lingering bugs in this area which hopefully will get tuned up over time as they get more bug reports and examples sent to them of failure cases.

But generally Modo is pretty good in this area, its n-gon triangulation failures tend to be pretty rare, and small in number.

If you can isolate it down to a small example, it would probably be good to send it to luxology so they could do something to fix it up.


> Of course this is probably a useless idea since a lot of ngons
> come up when you cut holes into flat faces, and those will
> never be convex.

Yeah basically after you have done a few booleans it will be pretty normal for there to be quite a large number of non-convex n-gons.

One other thing you might try when you run into this (which should hopefully be only an occasionally seen thing rather than the norm) is to use the "Divide larger than" parameter in MoI to dice polygons up and alter their structure. If you enter in a distance for "Divide larger than", any polygons larger than that size will be diced down, which tends to also cut complex n-gons into less complex n-gons.


> Another thing that might be useful for MoI noobs like me would
> be some kind of message display which explains why an operation
> can't be performed.

Yeah, I would like to have this in the future... It's unfortunately not always so easy for me to get this information, often times the operation that failed is some low level thing way deep down in one of the geometry library's algorithms and it is not easy to try and record the specific problem all the way from the "top level view" from the code...

- Michael