Multitouch modes for BioViz lab wall touch screen

[phil.cruz@…]

Multitouch would work better on the large display if rotation and zoom used a center at the touch point instead of the normal ChimeraX center of rotation. Using the normal center of rotation with such a large screen causes the rotation or zoom center to be far from where the user touches and the part the user is looking at flies away. This new mode could work if the user touches over an atom or ribbon or surface then that point is used as the center for rotation and zoom. If they touch over the background then it is not clear what depth to use. In that case we could guess a depth based on the normal center depth. It would be good to somehow nudge the user so they know they should touch the structure.

Another issue we encountered was that 3-finger translation moved the models 5 times faster than the fingers moved. It would probably be better to move at a 1-1 speed.

A third problem was that the IR touch sensing detected fingers a centimeter above the screen. So it was common that a 2-finger drag touching the wall would also pick up a third or fourth finger that were curled in the hand and not supposed to touch. Maybe the wall touch sensitivity could be adjusted to improve that.

We also learned that press and hold changes the touch point indicator from a circle to a square and that switches to right click. We may be able to better use that. I don't recall trying the right mouse modes in ChimeraX using that capability. That could greatly increase what could be done by touching the screen.

At the BioViz lab at NIAID last week we tried the wall touch screen and got multitouch gestures working by turning off the Windows OS intercepting 3 and 4-finger drags.