No announcement yet.

What is the meaning of WorldWind.LINEAR?

  • Filter
  • Time
  • Show
Clear All
new posts

  • What is the meaning of WorldWind.LINEAR?

    A WorldWind.Path has a pathType that can have one of three values: WorldWind.GREAT_CIRCLE, WorldWind.RHUMB_LINE and WorldWind.LINEAR. I have a page with one line of each path type going from N 34, W 118, 5000, 5000 m to N 43, W 71.2, 5000 m. All three are WorldWind.RELATIVE_TO_GROUND, extruded and followTerrain are false, useSurfaceShapeFor2D is true. I even set numSubSegments = 1 for the LINEAR line.

    The first problem I noticed is that in 3D, the lines are only 1 pixel wide and the LINEAR line does not show up. I found the line width issue addressed here ( Unless the LINER line is completely under one of the other two, why does it not show up. The order in which the lines are added to the layer is GREAT_CIRCLE, RHUMB_LINE and LINEAR.

    The second problem may be a matter of expectations. I was expecting a LINEAR path to just use a straight line between two points. When displayed over a Mercator map, where Rhumb-lines are straight lines, I'd expect LINEAR and RHUMB_LINE to match exactly. They are close, but not exact. When displayed over a North Gnomonic map, where Great Circles are straight lines, I'd expect LINEAR and GREAT_CIRCLE to match exactly. Instead, LINEAR is about as close a match to RHUMB_LINE on North Gnomonic as it is on Mercator.

    I had screen shots of all three, but upload attachments gave me an "Invalid file data" error message.

  • #2
    I figured out why the LINEAR line did not appear on the 3D globe. With the distance between the points and an altitude of 5,000 meters, a straight line goes through the surface of the Earth below the great circle path which follows the surface of the earth. Increasing the altitude of the LINEAR line to 500,000 meters makes the line appear on a 3D globe.


    • #3
      I liked this very much. I was looking for data regarding WorldWind.LINEAR and here is perfect for that. Benefits of CBD So many types of examples are easily accessible in this section. We can search by code.


      • #4
        WorldWind. LINEAR The shape's path or edges are drawn as a single straight line between their defining geographic coordinates.