Method and system for measuring an item depicted in an image
A method and system for measuring an object represented by a three dimensional model includes an algorithm for displaying the three dimensional object in a 2 dimensional space. Once rendered in two dimensions, a user can identify two points on the object in that two dimensional space and in accordance with the invention, the system can determine the distance between the two points in the three dimensional space of the object. The system and method can use a pick function to determine the coordinates of each point in three dimensional space as a function of the two dimensional coordinates of each point selected in the two dimensional display space and determine the distance between the three dimensional coordinates of each point in the three dimensional space. The system and method can also use a Z-buffered rendering algorithm for displaying the three dimensional object in a two dimensional image and determining the distance between two selected points in the two dimensional image as a function of Z value stored for each point. Alternatively, where Z-buffer information cannot be used, the system and method can project three dimensional rays through the selected points to the object and determine the depth (or distance) from the point of view of the viewer. The system and method can determine the distance between the selected points as a function of the depth information.
1. A method of measuring an object rendered on a display system connected to a network, the method comprising the steps of:
A) receiving from the network three dimensional source data representative of a model of an object in a three dimensional space;
B) rendering an image on said display system using said three dimensional source data;
C) identifying a first point on said display system without regard to the three dimensional source data and said image;
D) determining a first point on the object in the three dimensional space corresponding to the first point on the display system based upon said image;
E) identifying a second point on said display system without regard to the three dimensional source data and said image;
F) determining a second point on the object in the three dimensional space corresponding to the second point on the display system based upon said image;
G) determining a distance in three dimensional space between the first point on the object in the three dimensional space and the second point on the object in the three dimensional space; and
H) displaying the value of the determined distance on said display system to the user.
2. A method of measuring an object according to claim 1 wherein the step of determining said first point on the object in three dimensional space, includes determining a coordinate of said first point on the object in three dimensional space as a function of a Z value associated with the image at the first point on the display system and the step of determining said second point on the object in three dimensional space, includes determining a coordinate of said second point on the object in three dimensional space as a function of a Z value associated with the image at the second point on the display system.
3. A method of measuring an object according to claim 1 wherein the step of determining said first point on the object in three dimensional space, includes determining a coordinate of said first point on the object in three dimensional space as a function of a ray traced through the image at the first point on the display system and the step of determining said second point on the object in three dimensional space, includes determining a coordinate of said second point on the object in three dimensional space as a function of a ray traced through the image at the second point on the display system.
4. A method of measuring an object according to claim 1 wherein the step of determining said first point on the object in three dimensional space, includes determining a coordinate of said first point on the object in three dimensional space using a pick function and coordinates of the image at the first point on the display system and the step of determining said second point on the object in three dimensional space, includes determining a coordinate of said second point on the object in three dimensional space using a pick function and coordinates of the image at the second point on the display system.
5. A method of measuring an object according to claim 1 wherein the step of determining said first point on the object in three dimensional space, includes determining a coordinate of said first point on the object in three dimensional space using an inverted projection equation and coordinates of the image at the first point on the display system and the step of determining said second point on the object in three dimensional space, includes determining a coordinate of said second point on the object in three dimensional space using an inverted projection equation and coordinates of the image at the second point on the display system.
6. A method of measuring an object according to claim 1 wherein the step of determining the distance in three dimensional space, includes determining a distance between the first point on the object in three dimensional space and the second point on the object in three dimensional space as a function of at least one vector associated with each of the first point on the object in three dimensional space and the second point on the object in three dimensional space.
7. A method of measuring an object according to claim 1 wherein the step of determining the distance in three dimensional space, includes determining a distance between the first point on the object in three dimensional space and the second point on the object in three dimensional space as a function of orthogonal coordinates associated with each of the first point on the object in three dimensional space and the second point on the object in three dimensional space.
8. A system for measuring an object rendered on a display system connected to a network comprising:
A) an interface adapted for connecting said display system to a network and adapted for receiving from the network three dimensional source data representative of a model of an object in a three dimensional space;
B) a rendering engine adapted for rendered an image on said display system using said three dimensional source data;
C) a display control system for identifying a first point on said display system and for identifying a second point on said display system without regard to the three dimensional source data and the image; and
D) a processing system adapted for determining a first point on the object in the three dimensional space corresponding to the first point on the display system based upon said image, adapted for determining a second point on the object in the three dimensional space corresponding to the second point on the display system based upon said image; and adapted for determining a distance in three dimensional space between the first point on the object in the three dimensional space and the second point on the object in the three dimensional space.
9. A system for measuring an object according to claim 8 wherein the processing system is adapted for determining a coordinate of said first point on the object in three dimensional space as a function of a Z value associated with the image at the first point on the display system and adapted for determining a coordinate of said second point on the object in three dimensional space as a function of a Z value associated with the image at the second point on the display system.
10. A system for measuring an object according to claim 8 wherein the processing system is adapted for determining a coordinate of said first point on the object in three dimensional space as a function of a ray traced through the image at the first point on the display system and adapted for determining a coordinate of said second point on the object in three dimensional space as a function of a ray traced through the image at the second point on the display system.
11. A system for measuring an object according to claim 8 wherein the processing system is adapted for determining a coordinate of said first point on the object in three dimensional space using a pick function and coordinates of the image at the first point on the display system and adapted for determining a coordinate of said second point on the object in three dimensional space using a pick function and coordinates of the image at the second point on the display system.
12. A system for measuring an object according to claim 8 wherein the processing system is adapted for determining a coordinate of said first point on the object in three dimensional space using an inverted projection equation and coordinates of the image at the first point on the display system and adapted for determining a coordinate of said second point on the object in three dimensional space using an inverted projection equation and coordinates of the image at the second point on the display system.
13. A system for measuring an object according to claim 8 wherein the processing system is adapted for determining a distance between the first point on the object in three dimensional space and the second point on the object in three dimensional space as a function of at least one vector associated with each of the first point on the object in three dimensional space and the second point on the object in three dimensional space.
14. A system for measuring an object according to claim 8 wherein the processing system is adapted for determining a distance between the first point on the object in three dimensional space and the second point on the object in three dimensional space as a function of orthogonal coordinates associated with each of the first point on the object in three dimensional space and the second point on the object in three dimensional space.
15. A method of measuring an object according to claim 1 wherein the network is a global computer network.
16. A method of measuring an object according to claim 1 wherein the network is a wide area computer network.
17. A system for measuring an object according to claim 8 wherein the network is a global computer network.
18. A system for measuring an object according to claim 8 wherein the network is a wide area computer network.
19. A display system connected to a computer network for rendering an image, the display system comprising:
means for receiving from the network image data representing three dimensional data of an object;
means for rendering and displaying a two dimensional image based upon the image data;
means for selecting two points on a display without regard to the image data and the two dimensional image;
means for determining a distance in three dimensional space between points on the object corresponding to the selected two points on the display and the two dimensional image; and
means for displaying the distance.
20. The display system according to claim 19 , wherein the means for determining a distance includes:
means for determining a first point on the object in three dimensional space corresponding to a first one of the selected two points based upon the image data;
means for determining a second point on the object in three dimensional space corresponding to a second one of the selected two points based upon the image data; and
means for determining a distance in three dimensional space between the first point.