3D: Limit on-the-fly 3D rendering

[nicklally]

MDS and other calculations for the the 3D view slow things down considerably, especially since they are updated continuously to make the 3D view match the top interface. Some solutions might include:

1. Make a "RENDER" button to update 3D
2. Make a checkbox to enable/disable on-the-fly rendering (currently always on)
3. Make a separate 'window' for 3D render that a user can switch to—3D then renders on switch (Luke: at some point you sent me a library to do the switching, do you remember the link?)

[geoglrb]

Could also have rendering be always-on, but background, so implicitly lagged.

[nicklally]

Good idea, maybe we could implement multithreading?
http://keithwhor.github.io/multithread.js/
https://www.w3schools.com/html/html5_webworkers.asp

[geoglrb]

Is issue best described as 3D rendering or... 'projection'/MDSing? If MDS is the problem, then what if the title were to make that clear? A second issue for other parts of 3D rendering (that may be more classically 'rendering'?)

[nicklally]

I added a separate MDS issue. I think rendering/calculating for 3D will always be a bottleneck of sorts since that's where most of the calculations happen.