"move planes" mouse mode behavior with multiple maps

[Elaine Meng]

I don't know if this is a request for enhancement or a bug report, but when I have one map shown as a single plane or orthoplanes and another map in some other style, it currently adjusts the box of the non-plane box. Seems like it would be better for it to move the plane display instead and leave the box of the other thing alone.

An example is if I have a segmentation shown as a surface and a CT scan shown as a plane. I want to move the plane through the segmentation contour, not adjust the box size of the segmentation.

[Tom Goddard]

This seems like a very specific use case. The current behavior is that the volume face under the mouse when it is clicked is what is moved. So if the plane you want to move is inside another displayed volume then you won't be able to move it because you will always get the enclosing volume face. In VR that may not be a problem because you just stand inside or put your hand inside the enclosing volume and point at the plane and it will choose the plane to move. Maybe that could also be done with the mouse if move the camera inside the volume to click with the mouse on the plane. But that is not natural and no one would figure that out. Still I think your case is too specialized to make an exception to the simple rule that the volume face that moves is the nearest one under the mouse. For a single plane you can use the plane slider.

Another idea is to have a specific mode that just moves planes, and another mode that just crops a box -- in other words separate the current overloaded mode into two mouse modes. That might be sensible.

[Elaine Meng]

Two separate mouse modes sounds good.  Although I don’t think it’s urgent, I also don’t think the use case is that obscure for medical data: i.e. moving planes through a segmentation volume that wasn’t even in cropping mode beforehand, so it didn’t occur to me that cropping would be activated.  It took me a while to understand why this other annoying box kept appearing and the plane didn’t move.  A slider is OK for one plane, but it makes you look away from the graphics, and if you have orthoplanes it would be especially unwieldy.

[goddard@…]

There is no such thing as a “cropping mode” for a volume — maybe you mean the outline box was not shown.  A more troublesome aspect of trying to show a single plane inside a volume in this way is it should hit the two transparent models problem — the plane may look completely on top or completely below the volume.  If it is an opaque plane then it will not be a problem.

[Elaine Meng]

In Volume Viewer (Chimera) you had to check a box to start cropping with the mouse, and in these other DICOM apps I’ve been learning about, one has to specifically go into some cropping mode.  

Of course I realize (NOW) that that is the same as clicking the mouse-mode icon in ChimeraX, but I was not in the mindset of altering the volume that I’d never cropped before (also it was registering in my mind as a surface, not the giant box around it), but moving the plane that I’d just shown. The basic problem is just that it's dual-purpose mode and it didn’t occur to me that it was going to start doing the “other” thing, which is most straightforwardly solved by having two separate modes.