System and method for determining line-of-sight volume for a specified point

1. A system for determining a Line-of-Sight volume for a specified point within a three dimensional model comprising:

a focus point defined in three dimensional space;

a plurality of data files each corresponding to a geographic feature that may impact a Line-of-Sight from the focus, each data file having data about geometric entities that make-up a geographic feature; and

a processor operative for processing the data files and creating a series of polygons that represent a shell of a Line-of-Sight volume to the focus at a specified resolution based on the processed data files.

2. A system according to claim 1 , wherein the processor is operative for processing each data file as a minimally-sized bounding volume that contains the geometric entities that make-up a geographic feature and determining if a ray cast from the focus to the closest point of the bounding volume intersects the initial shape of the volume within the specified distance.

3. A system according to claim 1 , wherein a geographic feature comprises a building.

4. A system according to claim 1 , and further comprising a single output file as a series of polygons that represent the shell of the Line-of-Sight volume.

5. A system according to claim 1 , wherein said processor is operative for computing the azimuth and elevation range of a polygon and determining the distance from the focus to a point lying within the polygon.

6. A system according to claim 1 , wherein each data file comprises a collection of polygons with each polygon's vertices contained within a common plane.

7. A system according to claim 1 , wherein each polygon comprises a triangle.

8. A system according to claim 1 , wherein said processor is operative for changing the resolution to enhance rendering speed for calculating the shell of the Line-of-Sight volume.

9. A system according to claim 1 , wherein said processor is operative for defining different surfaces of the shell.

10. A system according to claim 9 , wherein said shell comprises a general spline based or NURBS (Nonuniform Rational B-Splines) surface.

11. A system for determining a Line-of-Sight volume for a specified point within a three dimensional model comprising:

a focus point defined in three dimensional space as part of an initial shape for a volume defined as if there were no obstructions from the focus based on a specified distance;

a plurality of data files each corresponding to a geographic feature that may impact a Line-of-Sight from the focus, each data file having data about geometric entities that make-up a geographic feature; and

a processor operative for processing the data files and creating a series of polygons that represent a shell of a Line-of-Sight volume to the focus at a specified resolution based on the processed data files.

12. A system according to claim 11 , wherein said initial shape comprises a full hemisphere shape.

13. A system according to claim 11 , wherein said initial shape comprises one of an upper or lower hemisphere.

14. A system according to claim 11 , wherein said initial shape comprises a horizontal cross section of a sphere having user defined upper and lower vertical distances either relative to the focus or if geospatially referenced in absolute altitudes.

15. A system according to claim 11 , wherein said initial shape comprises longitudinal hemispheres based on either selected directions or an amount of obscuration.

16. A system according to claim 11 , wherein said initial shape comprises conical shapes from one selected point towards the focus with a selected field of view angle.

17. A system according to claim 11 , wherein the processor is operative for processing each data file as a minimally-sized bounding volume that contains the geometric entities that make-up a geographic feature and determining if a ray cast from the focus to the closest point of the bounding volume intersects the initial shape of the volume within the specified distance.

18. A system according to claim 11 , wherein a geographic feature comprises a building.

19. A system according to claim 11 , and further comprising a single output file as a series of polygons that represent the shell of the Line-of-Sight volume.

20. A system according to claim 11 , wherein said processor is operative for computing the azimuth and elevation range of a polygon and determining the distance from the focus to a point lying within the polygon.

21. A system according to claim 11 , wherein each data file comprises a collection of polygons with each polygon's vertices within a common plane.

22. A system according to claim 11 , wherein each polygon comprises a triangle.

23. A system according to claim 11 , wherein said processor is operative for changing the resolution to enhance rendering speed in calculating the shell of the Line-of-Sight volume.

24. A system according to claim 11 , wherein said processor is operative for defining different surfaces of the shell.

25. A system according to claim 24 , wherein said shell comprises a general spline based or NURBS (Nonuniform Rational B-Splines) surface.

26. A method for determining a Line-of-Sight volume for a specified point within a three dimensional model, which comprises:

designating a point in three dimensional space as a focus;

processing a plurality of data files, each data file corresponding to a geographic feature that may impact a Line-of-Sight from the focus, wherein each data file includes data about geometric entities that make-up a geographic feature; and

creating a series of polygons that represent a shell of a Line-of-Sight volume to the focus at a specified resolution based on the processed data files.

27. A method according to claim 26 , which further comprises processing each data file as a minimally-sized bounding volume that contains the geometric entities that make-up a geographic feature and determining if a ray case from the focus to the closest point of the bounding volume intersects the initial shape of the volume within the specified distance.

28. A method according to claim 26 , which further comprises creating a single output file as a series of polygons that represent the shell of the Line-of-Sight volume to the focus.

29. A method according to claim 26 , which further comprises computing the azimuth and elevation range of a polygon and determining the distance from the focus to a point lying within the polygon.

30. A method according to claim 26 , which further comprises defining each data file comprises as a collection of polygons with each polygon's vertices in a common plane.

31. A method according to claim 26 , which further comprises defining each polygon as a triangle.

32. A method according to claim 26 , which further comprises changing the resolution to enhance rendering speed in calculating the shell of the Line-of-Sight volume.

33. A method according to claim 26 , which further comprises defining different surfaces of the shell.

34. A method according to claim 33 , which further comprises defining a general spline based or NURBS (Nonuniform Rational B-Splines) surface.

35. A method for determining a Line-of-Sight volume for a specified point within a three dimensional model, which comprises:

designating a point in three dimensional space as a focus; generating an initial shape of a volume as if there were no obstructions from the focus based on a specified distance;

processing a plurality of data files, each corresponding to a geographic feature that may impact a Line-of-Sight from the focus, wherein each data file includes data about geometric entities that make-up a geographic feature; and

creating a series of polygons that represent a Line-of-Sight volume to the focus at a specified resolution based on the processed data files.

36. A method according to claim 35 , which further comprises generating a full hemisphere shape.

37. A method according to claim 35 , which further comprises generating one of an upper or lower hemisphere shape.

38. A method according to claim 35 , which further comprises generating a horizontal cross section of a sphere having user defined upper and lower vertical distances either relative to the focus or if geospatially referenced in absolute altitudes.

39. A method according to claim 35 , which further comprises generating longitudinal hemispheres based on either selected directions or an amount of obscuration.

40. A method according to claim 35 , which further comprises generating conical shapes from one selected point towards the focus with a selected field of view angle.

41. A method according to claim 35 , which further comprises processing each data file as a minimally-sized bounding volume that contains the geometric entities that make-up a geographic feature and determining if a ray case from the focus to the closest point of the bounding volume intersects the initial shape of the volume within the specified distance.

42. A method according to claim 35 , which further comprises creating a single output file as a series of polygons that represent a shell of the Line-of-Sight volume to the focus.

43. A method according to claim 35 , which further comprises computing the azimuth and elevation range of a polygon and determining the distance from the focus to a point lying within the polygon.

44. A method according to claim 35 , which further comprises defining each data file comprises as a collection of polygons with each polygon's vertices in a common plane.

45. A method according to claim 35 , which further comprises defining each polygon as a triangle.

46. A method according to claim 35 , which further comprises changing the resolution to enhance rendering speed in calculating the shell of the Line-of-Sight volume.

47. A method according to claim 35 , which further comprises defining different surfaces of the shell.

48. A method according to claim 47 , which further comprises defining a general spline based or NURBS (Nonuniform Rational B-Splines) surface.