I don't have time at the moment to try building it in ICE, but conceptually maybe this would be a start:
1. visualize your 2 points on a sphere 2. create a duplicate sphere at the same location as the original 3. rotate the new sphere about local X and Z until both points lie on the equator 4. rotate the new sphere about local Y to put 0-degrees longitude on one point -- call this Y-rot value "A" 5. rotate the new sphere about local Y to put 0-degrees longitude on the 2nd point -- call this Y-rot value "B" 6. subtract A from B -- your path is now a Y-rotation about the new sphere's center or: 1. get the vector from Point A to point B 2. make a projection from the center of the sphere of the vector onto the sphere's surface 3. subdivide the projected arc On Wed, Jul 11, 2012 at 3:11 PM, Jeff McFall <[email protected]> wrote: > Hi all, > > I am trying to find the best way to move a point along a path of the > shortest distance between two points on the surface of a sphere. > Probably a pretty basic geometry function but I am having trouble even > starting. > >From what I can gather the way to solve this is through a Great Circle > calculation > > I am getting hung up on the long/lat conversion to 3Dspace, not to mention > how to interpolate the movement along this path once calculated > > Anyone happen to have a tutorial or know of a compound that could help? > in ICE of course > > many thanks > Jeff > > > >
