thisleenoble

Eep! Yep that's the difference!
This is surely a bug.
The original "Fit to Plane" correctly generates a pair of values for Rotation and Skew. It is as if that isn't being removed / zeroed before the new values are calculated.

I have previously filed an overlapping feature request but after consideration I actually think this is a bug in the Isometric/Cube grid implementation which if it were to be fixed would do wonders for the usability of this amazing feature. The attached video demonstrates.
1) Draw three identical squares int he flat view.
2) Move each square in turn to the Top, Side and Front planes, bring them together and you get a facsimile of a cube.
3) Now move one of those faces to a different plane by highlighting and clicking "Fit to plane" in the Isometric studio palette and you'll find the apparent dimensions change.
This action should retain the intrinsic dimensions of the original flat shape, enabling the user to flip objects between the planes. Returning them to the 2D view would also be desirable as the application "knows" the original dimensions it seems like this should be possible.
 
Cube-Bug.mov

Your grid is a perfect isometric grid so the skew values are identical for all three planes.
For a minute there I had hope that I'd missed something. You gave me the hope!

I've had a further thought on this, and I think I might have guessed where you're heading with the solution for the perspective transform. Ok, so I was playing with an isometric-ish grid and moving flat objects onto grid planes. The next logical step, for me, is to be able to move objects from one plane to another, switching from front to side. I mean the objects clearly have current knowledge of which plane they are in so that the regular transform handles conform to that plane, the point being it "knows" it's real dimensions if it were face on, so despite the fact there's no way to return an object to the flat face-on plane, it doesn't seem that much of a stretch to be able to do so. Then once you can freely move objects from flat view to any plane and back again this gives you far more control if you wanted to change the underlying grid.
For example, say you start with a straight isometric view and build out some objects, and latterly decide you want a lower perspective, you can change the grid but you're stuffed when it comes to migrating your objects to the new grid. However, if they have a reference size described in the flat view, those objects could be transformed through that flat view and back into the newly defined grid planes.
Combined with the ability to "pinch" the grid cube to create non-parallel 3D grids you'd effectively be able to change the perspective on any 3D construction (with obvious certain limits).
This would be the type of thing that I see fitting under the umbrella of "wanting to do the right thing and not just copy how other software works (i.e. the perspective/warping tool)".

As far as I am able to tell, this facility is only accessible via the contextual menu on an object. My understanding of the intent for a contextual menu is it should only present options which are also accessible via the normal menu hierarchy. I have been unable to locate it there and it doesn't appear to be listed anywhere in the shortcut preferences either. Maybe just a simple omission but it would be handy.

Hi,
 
AP 1.5 beta is coming - in a couple of weeks or so.. here are a few of the things we can look forward to:
 
- HDR merging.
- HDR toning.
- Full 32bit unbounded linear editing, including (correct) OpenEXR, Radiance support.
- Focus merging.
- Live Projections (edit in perspective projection, equirectangular projection).
- Macro recording and playback gallery.
- Batch processing.
- Layer linking.
- Magnetic selection tool.
- Polygonal selection tool.
- Ability to round-trip PSD (for use with DAM applications).
 
- Lots of small improvements.
 
Hope this helps,
 
Andy.