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Should Lines be Straight or Curved?

Nov 17, 2008 at 1:21 AM
Do we mimik the Virtual Earth approach of drawing a staright line between two points or do we actually take into consideration the curves of the earth and plot the line as a curve on the flat projection = straight when on a sphere?
Should we make this an option?
Nov 17, 2008 at 2:38 AM
I hope this is not a stupid question/comment but is the map(s) shown in the control not in a 2D style
where everything is just stright up and down (north, south) or stright left and right (east west)..?

I am not sure how the curved lines would fit on the map,
or am I missing something or just got it completely wrong...?
Nov 18, 2008 at 1:55 AM
Goto http://maps.live.com/?mkt=en-us
Open the collections tab and draw a 2D "straight line" from across a large section of the world.
Then change to 3D mode. Is your line still "Straight"? The Earth is a sphere (almost) and the 2D projection used distorts the surface to make it flat.
If you actually draw a "Straight" or direct, shortest path, line it will appear to be curved on the 2D projection.
But the issue is will people find it a little odd when drawing a box that the edges are curved? I think we may need to have this an optional - what do you think?
John.
Nov 18, 2008 at 10:57 PM
Edited Nov 18, 2008 at 11:02 PM
Ultimately, we should probably check the Projection type of the BaseLayer when drawing lines.  It probably doesn't make sense to drawn curved lines when the projection is set to Mercator.  In Mercator everything is straight since the meridians intersect at 90 degree angles.  Since OSM and VE (2D) and most others use Mercator, this is probably a bridge we can cross when we take on a TileSource that uses something other than Mercator projection.