Hui Majik,
Have the surface seperate, then select all of its edges and hit delete= untrim.

Holy cats!

Thanks Burr! Found you have to not only select the edges from the trimmed regions, but the BRep seam edges as well.

Or at least in my case, the seam was connected to the trimmed edge. Otherwise, it did not work until everything was selected.

That can come in useful, especially when the "inspiration" is an afterthought.

Hi Mike, check out the object repair tutorial for a pretty in depth covering of that:
http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17

Also here's a shorter one focused just on how to untrim:
http://moi3d.com/forum/index.php?webtag=MOI&msg=444.4

You basically need to get the boundary that you want to remove to be made up of all unjoined edges (delete things or use Edit > Separate as necessary) then select all the edges of the boundary you want to remove and push delete to remove that trim boundary and restore the underlying surface there.

If you want to untrim everything on a surface, select one edge and then do Ctrl+A to select all its edges before pushing delete.

There's also a plug-in "UntrimAll" which gives a shortcut for untrimming everything in a whole solid in one step here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4068.6

- Michael

Hi Mike, yup the seam is a bit tricky - when a trim boundary touches a seam the seam edge is a part of the whole boundary and so it must also be selected in order for it to recognize that you're trying to remove the entire boundary.

I suppose that could be tuned up so that you wouldn't have to pick the seam, I've added a note to myself to look into that.

- Michael

Thank a million Michael!

That was so easy, I'm not surprised I missed that ability all this time.

I played around with it and found out how using ShrinkTrimmedSrf in conjunction with it can give you neat residual surfaces to work from when bringing back the (secondary) trim surfaces themselves from the dead.


Speaking of the seams...

I can hide them individually as sometimes they seem to be more or less clutter on an object. But then again, when they are useful, you need to see them there.
If I could make a teensie request, it would be to allow for a separate coloration setting in the .ini. I myself might make them a barely visible gray.
Or turn them off from visibility completely, say, unless you select the whole object then it is visible.
But this is just the "modder" in me asking. :-)

Thanks again!