Hi blankidea, I'm glad that you are liking MoI and those are some great results!

> What ensures the surfaces do not fit (gaps).
> I know now how it works in order to avoid such gaps
> (Always build on existing geometry).

You're talking about OBJ export here too, right?

If you've created 2 surfaces that are sitting right next to one another, make sure that you use the Edit > Join command to join them together so that they share a common joined edge between them.

MoI does extra work on joined edges to make a "watertight" mesh that has the same vertex structure along the joined common edges so that there are no holes in the mesh. If you have separate surfaces that were created individually and just happen to be sitting next to one another then they get meshed separately and the vertices may be different where they touch. So make sure they are joined together to avoid that.

Note though that the meshes for each surface can have different UV Quad structures, the underlying quads for the mesh come from the UV space of each surface, see these previous posts for some more information on vertex alignment:

http://moi3d.com/forum/index.php?webtag=MOI&msg=1536.30
http://moi3d.com/forum/index.php?webtag=MOI&msg=2102.45


> Extra: Resizing the window (bad performance)

Yup, this is one of the last remaining areas I have left to work on.


> also when i open the app the window is only filled half.

I think this one may be solved by some fixes that will be coming for the next beta but I'm not entirely sure. Please let me know if you run into it again when the next beta is out.

I'm not quite sure yet when the next OSX beta will be out, sometime pretty soon but I'll be out of town for a week so if I can't get it out tomorrow it won't be until sometime the week after next.

Thanks,
- Michael