REFINING WIREFRAME BUILDING MODELS USING POINT CLOUDS

1 . A method for corner refinement of a building wireframe model, the method comprising:

providing a point cloud of a building;

providing the building wireframe model generated from the point cloud, wherein the building wireframe model comprises a plurality of façades each façade forming a planar polygon, and wherein each planar polygon comprises a plurality of corners;

displaying the building wireframe model, wherein each of the plurality of corners is user selectable;

selecting one of the plurality of corners;

overlaying the selected corner on the point cloud; and

refining a placement of the selected corner in accordance with the point cloud.

2 . The method of claim 1 , wherein the overlaying the selected corner further comprises:

highlighting a surrounding geometry of the selected corner, wherein the highlighting comprises:

gathering all points in the point cloud within a highlighting distance of the selected corner;

computing surface variation values for all points gathered; and

coloring all points gathered in accordance with surface variation values to highlight the surrounding geometry.

3 . The method of claim 2 , wherein the highlighting distance is a range of approximately 20.0 to 100.0 cm.

4 . The method of claim 1 , further comprising:

assigning a permanent identification number to each of the plurality of corners.

5 . The method of claim 1 , wherein the refining the placement of the selected corner further comprises:

selecting a seed point for each façade adjacent to the selected corner, each seed point within a seed point distance of the selected corner;

gathering all points of the point cloud within a gathered distance of the selected corner;

growing a region for the selected seed points with the gathered points in the point cloud for each facade;

fitting a local plane to the region for each facade;

selecting a refined corner from an intersection of the local planes; and

displaying the seed points and the refined corner.

6 . The method of claim 5 , further comprising:

after displaying the seed points, moving any of the seed points by a user;

growing the region for the moved seed points with the gathered points in the point cloud for each facade;

fitting the local plane to the region for each facade;

selecting the refined corner from an intersection of the local planes; and

displaying the seed points and the refined corner.

7 . The method of claim 5 , wherein the seed point distance is a range of approximately 10.0 to 30.0 cm.

8 . The method of claim 5 , wherein the gathered distance is a range of approximately 50.0 to 100.0 cm.

9 . The method of claim 5 , wherein if the local planes are not parallel, the method further comprises:

selecting new seed points for each façade adjacent to the selected corner, each new seed point within a new seed point distance from the selected corner, wherein the new seed point distance is further than the seed point distance;

gathering all points in the point cloud within the gathered distance of the selected corner;

growing a new region for the selected new seed points with the gathered points in the point cloud for each facade;

fitting a new local plane to the new region for each facade;

selecting the refined corner from an intersection of the new local planes; and

displaying the new seed points and the refined corner.

10 . The method of claim 9 , further comprising:

after displaying the new seed points, moving any of the new seed points by a user;

growing the region for the moved new seed points with the gathered points in the point cloud for each facade;

fitting the local plane to the region for each facade;

selecting the refined corner from an intersection of the local planes; and

displaying the new seed points and the refined corner.

11 . The method of claim 9 , wherein the new seed point distance is a range of approximately 40.0 to 80.0 cm.

12 . The method of claim 1 , wherein the refining the placement of the selected corner further comprises:

moving the selected corner manually by a user.

13 . The method of claim 1 , wherein the refining the placement of the selected corner further comprises:

selecting a façade adjacent to the selected corner; and

nudging the selected corner along the selected façade.

14 . A method for refining wireframe building models using point clouds comprising:

providing a point cloud of a building;

providing the building wireframe model generated from the point cloud;

applying corner refinement to the building wireframe model;

applying edge refinement to the building wireframe model; and

applying fenestration delineation to the building wireframe model.

15 . The method of claim 14 , wherein the applying corner refinement to the building wireframe model further comprises:

displaying the building wireframe model, wherein

the building wireframe model comprises a plurality of façades, each façade forming a planar polygon, wherein

each planar polygon comprises a plurality of corners; and wherein

each of the plurality of corners is user selectable;

selecting one of the plurality of corners;

overlaying the selected corner on the point cloud; and

refining a placement of the selected corner in accordance with the point cloud.

16 . The method of claim 15 , wherein the overlaying the selected corner further comprises:

highlighting a surrounding geometry of the selected corner, wherein the highlighting comprises:

gathering all points in the point cloud within a highlighting distance of the selected corner;

computing surface variation values for all points gathered; and

coloring all points gathered in accordance with surface variation values to highlight the surrounding geometry.

17 . The method of claim 15 , wherein the refining the placement of the selected corner further comprises:

selecting a seed point for each façade adjacent to the selected corner, each seed point within a seed point distance of the selected corner;

gathering all points of the point cloud within a gathered distance of the selected corner;

growing a region for the selected seed points with the gathered points in the point cloud for each facade;

fitting a local plane to the region for each facade;

selecting a refined corner from an intersection of the local planes; and

displaying the seed points and the refined corner.

18 . The method of claim 17 , further comprising:

after displaying the seed points, moving any of the seed points by a user;

growing the region for the moved seed points with the gathered points in the point cloud for each facade;

fitting the local plane to the region for each facade;

selecting the refined corner from an intersection of the local planes; and

displaying the seed points and the refined corner.