3D versus 2D (and Which 2)

• Plan was to Build the internal display list in 3D
• Only the Transmit phase would need to know the final view

This meant that a common set of code could drive both the high-end 3D workstations and the more common 2D devices.

But we later found many situations where the Build stage needed to know the view.

• Where do you pin a number onto a helical track (track's end may be off the display)?
• You may want to sum energy over the non-displayed dimension (an in an SLD Thermometer-style Calorimeter plot)
• Different data wants different coordinate systems (as in an SLD Unrolled Liquid Argon Calorimeter plot)

3D arbitrary rotations do have value, but their are some valuable images that are not mere 2D camera views of a 3D space.

It's Hard to Get Oriented

• Most users spend most of their time looking at standard three views
• Suspect that the problem is it's hard to get oriented in complex views

Multiple, Well Correlated Views are Helpful

• Allow not only different transformations, but different sets of object selections
• Use color assignments or other forms of highlighting to help the user pick out the same object in different views