| 摘要 |
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. |
