Specify the view on model contents

At TPAC we discussed the necessity to point the view into a <model> element at specific locations within it, e.g. to focus on specific features of a car.

We also agreed that for both reasons of complexity for the author and compatibility across platforms, that supplying view information like a 4x4 projection matrix were not appropriate. Instead, to follow something closer to the style indicated with the existing proposed JS syntax, i.e setCamera({pitch:10, yaw:10, scale:1}).

My suggestion is to specify an {x,y,z} object as an optional origin or pivot parameter on that setCamera call:

myShelf.setCamera( { 
  pitch:0, 
  yaw:20, 
  scale:1, 
  pivot: {x:0, y:1, z:0}
} );

and in fact for the other parameters to be made optional as well, with the presumption that no supplied value implies to retain the same one.

Start with this issue and the existing proposed JavaScript setCamera syntax. Review the suggested pivot/origin object and the optional-parameter behavior, then check the discussion for an agreed direction. Done means the view-control API and its semantics are specified clearly enough for implementation.