Method and apparatus for evaluating sight distance

Abstract

A method of sight distance analysis comprising: acquiring a scene-graph representation comprising three dimensional entities; acquiring at least one three dimensional object representation within the scene graph environment; acquiring a target object representation; selecting at least one camera position; positioning the acquired target object representation in the scene graph representation at a distance from the selected at least one camera position; and determining a visibility factor for the positioned target object representation.

1 . A method of sight distance analysis comprising:
 acquiring a scene-graph representation comprising three dimensional entities;   acquiring at least one three dimensional object representation within the environment of said scene graph;   acquiring a target object representation;   selecting at least one camera position;   positioning said acquired target object representation in said scene graph representation at a distance from said selected at least one camera position; and   determining a visibility factor for said positioned target object representation.   
     
     
         2 . A method of sight distance analysis according to  claim 1 , wherein said acquired at least one three dimensional object representation is constituted of a light detection and ranging (LIDAR) model. 
     
     
         3 . A method of sight distance analysis according to  claim 1 , wherein said determining a visibility factor comprises:
 counting the number of pixels attributed to said positioned target object representation when said target object representation is rendered alone;   counting the number of pixels attributed to said positioned target object representation when said three dimensional entities are rendered; and   determining the difference between said counted pixels when said target object representation is rendered alone and when said three dimensional entities are rendered.   
     
     
         4 . A method according to  claim 1  further comprising:
 animating said selected camera position along a path; and 
 generating a report for a plurality of points along said path, said report comprising observer position, target position and visibility factor for said target object at each of said plurality of points, wherein said visibility factor is a function of transparency of said acquired at least one three dimensional object representation within said scene graph environment. 
 
     
     
         5 . A method of sight distance analysis according to  claim 4 , wherein said scene-graph representation is of an infrastructure, and said distance is dynamically calculated along said animation path responsive to at least one of a current speed, incline of said infrastructure and braking coefficient. 
     
     
         6 . A method of sight distance analysis according to  claim 1 , wherein said distance is user determined. 
     
     
         7 . A method of sight distance analysis according to  claim 1 , wherein said distance is calculated responsive to at least one of a defined speed and a parameter of said representation. 
     
     
         8 . A method of sight distance analysis according to  claim 1 , wherein said determining a visibility factor for said positioned target object representation comprises:
 rendering said target object representation without rendering said at least one three dimensional object representation intervening between said observer and said target object representation;   calculating a metric of said target object representation rendered without said intervening at least one three dimensional object representation;   rendering said target object representation while rendering said at least one three dimensional object representation intervening between said observer and said target object representation;   calculating a metric of said target object representation rendered with said intervening at least one three dimensional object representation; and   determining a visibility factor as a function of the difference between said calculated metric of said target object representation rendered without said intervening at least one three dimensional object representation and said calculated metric of said target object representation rendered with said intervening at least one three dimensional object representation.   
     
     
         9 . A method of sight distance analysis according to  claim 1 , wherein said determining a visibility factor for said positioned target object comprises:
 computing an axis aligned bounding box for said positioned target object;   enlarging said computed bounding box by a buffer value to define an area;   rendering a photorealistic image of the defined area with said positioned target object turned on;   rendering a photorealistic image of the defined area with said positioned target object turned off; and   calculating an RGB pixel difference between said rendered photorealistic image with said target object turned on and said rendered photorealistic image with said target object turned off.   
     
     
         10 . A method of sight distance analysis according to  claim 1 , wherein said determining a visibility factor for said positioned target object comprises:
 computing an axis aligned bounding box for said positioned target object;   enlarging said computed bounding box by a buffer value to define an area;   rendering a photorealistic image of the defined area with said positioned target object turned on;   calculating a spatial frequency of said photorealistic image of the defined area with said positioned target object turned on;   rendering a photorealistic image of the defined area with said positioned target object turned off;   calculating a spatial frequency of said photorealistic image of the defined area with said positioned target object turned off; and   generating a spatial frequency visibility factor responsive to the difference between said calculated spatial frequency with said target object turned on and said target object turned off.   
     
     
         11 . A computing system for sight distance analysis comprising a computer and a monitor in communication therewith, said computer being operative to:
 acquire a scene-graph representation comprising three dimensional entities;   acquire at least one three dimensional object representation within said scene graph environment;   acquire a target object representation;   select at least one camera position;   position said acquired target object representation in said scene graph representation at a distance from said selected at least one camera position; and   determine a visibility factor for said positioned target object representation.   
     
     
         12 . A computing system for sight distance analysis according to  claim 11 , wherein said acquired at least one three dimensional object representation is constituted of a light detection and ranging (LIDAR) model. 
     
     
         13 . A computing system for sight distance analysis according to  claim 11 , wherein said determine a visibility factor comprises:
 count the number of pixels attributed to said positioned target object when said target object is rendered alone;   count the number of pixels attributed to said positioned target object when said three dimensional entities are rendered; and   determine the difference between said counted pixels when said target object is rendered alone and when said three dimensional entities are rendered.   
     
     
         14 . A computing system for sight distance analysis according to  claim 11 , wherein said computer is further operative to:
 animate said selected camera position along a path; and   generate a report for a plurality of points along said path, said report comprising observer position, target position and visibility factor for said target object at each of said plurality of points, wherein said visibility factor is a function of transparency of said acquired at least one three dimensional object representation within said scene graph environment.   
     
     
         15 . A computing system for sight distance analysis according to  claim 14 , wherein said scene-graph representation is of an infrastructure, and said distance is dynamically calculated along said animation path responsive to at least one of a current speed, incline of said infrastructure and braking coefficient. 
     
     
         16 . A computing system for sight distance analysis according to  claim 14 , wherein said scene-graph representation is of an infrastructure and wherein said computer is further operative to:
 dynamically calculate said distance along said animation path responsive to at least one of a current speed, incline of said infrastructure and a braking coefficient.   
     
     
         17 . A computing system for sight distance analysis according to  claim 11 , wherein said determining a visibility factor for said positioned target object comprises:
 render said target object without rendering said at least one three dimensional object representation intervening between said observer and said target object;   calculate a metric of said target object rendered without said intervening at least one three dimensional object representation;   render said target object while rendering said at least one three dimensional object representation intervening between said observer and said target object;   calculate a metric of said target object rendered with said intervening at least one three dimensional object representation; and   determine a visibility factor as a function of the difference between said calculated metric of said target object rendered without said intervening at least one three dimensional object representation and said calculated metric of said target object rendered with said intervening at least one three dimensional object representation.   
     
     
         18 . A computing system for sight distance analysis according to  claim 11 , wherein said determining a visibility factor for said positioned target object comprises:
 compute an axis aligned bounding box for said positioned target object;   enlarge said computed bounding by a buffer value to define an area;   render a photorealistic image of the defined area with said positioned target object turned on;   render a photorealistic image of the defined area with said positioned target object turned off; and   calculate an RGB pixel difference between said rendered photorealistic image with said target object turned on and said rendered photorealistic image with said target object turned off.   
     
     
         19 . A computing system for sight distance analysis according to  claim 11 , wherein said determine a visibility factor for said positioned target object comprises:
 compute an axis aligned bounding box for said positioned target object;   enlarge said computed bounding box by a buffer value to define an area;   render a photorealistic image of the defined area with said positioned target object turned on;   calculate a spatial frequency of said photorealistic image of the defined area with said positioned target object turned on;   render a photorealistic image of the defined area with said positioned target object turned off;   calculate a spatial frequency of said photorealistic image of the defined area with said positioned target object turned off; and   generate a spatial frequency visibility factor responsive to the difference between said calculated spatial frequency with said target object turned on and said target object turned off.   
     
     
         20 . A method of sight distance analysis comprising:
 acquiring an infrastructure as a scene-graph comprising three dimensional entities;   acquiring a nominal location for a moving observer in relation to a path on said infrastructure;   acquiring a distance to a target, said target being maintained at said distance from said moving observer;   calculating for a plurality of points along said path on said infrastructure a straight line between said moving observer and said target;   defining a 2 dimensional polyline representation of a visual intrusion zone; and   projecting said visual intrusion zone on a representation of said scene-graph.