[X3D-Public] LineSensor

[doug sanden]

Freewrlians implemented LineSensor node (not in specs) in freewrl, to see how it would work. 
http://dug9.users.sourceforge.net/web3d/tests/sensors/LineSensorLocalTrack.x3d
Works good.

-Doug
more..

The idea for that came up in discussions with Max Limper of X3Dom here earlier this year, when trying to drag axis handles for an editor. PlaneSensor is 'degenerate' when looking edge-on to the PlaneSensor's plane. We could tell from the asymmetries trying to use PlaneSensor that the original designers had missed this use case.
http://dug9.users.sourceforge.net/web3d/tests/sensors/PlaneSensor.x3d

LineSensor fields are like a PlaneSensor except:
- float offset (vs SFVec2f)
- float minPosition, maxPosition (vs SFVec2f)


LineSensor also has a degenerate case: when the line is coming right at the viewer. But that's less frequent and more intuitive for users. The best way to use it: put the LineSensor as a [grand] child of a transform that the linesensor is going to move via a route. Otherwise if you put it at the world level, there are other degenerate cases, such as when your LineSensor axis is to the right and your sensitized geometry to the left as seen from the viewer.