Hi Sun,

> The only problems I've encountered with MOI are the inherent
> size limit of 32bit apps (any chance for a 64 bit version of MOI?),

Probably not anytime soon, as there is quite a bit of work involved in that including that I would need to move to a new compiler and update all libraries that MoI uses. It's a significant undertaking.


> and screwed up normals for surfaces that aren't closed solids,
> like a cylinder with open ends for example. (I guess there's no
> way for it to know which way is 'out')

Yeah an object that is not a closed volume does not have any automatic way to detect which side is the "outside" - like for example if you have an object that is just a plane all by itself there is no way for MoI to know if that plane is actually the front side of the box or the back side of the box and so the normal orientation will end up being arbitrary and will depend on factors like if you happened to draw some of the generator curves clockwise or counter-clockwise and stuff like that.

The same thing will happen in any program where you have open objects.

You can use the Flip command in MoI if you need to flip an open object's normal orientation so that it will generate a mesh with the opposite normals:
http://moi3d.com/2.0/docs/moi_command_reference10.htm#flip

But really the easiest thing is to just turn on double-sided rendering and display instead of only doing single sided rendering in your rendering program. That way your objects will render the same no matter which way happens to be the positive surface normal direction.

- Michael