Modify Order of Points
The action „Modify Order of Points“ on dialog Modify Objects (also available from the context menu of polylines) enables to subsequently change the sequence of polygon points.
Reverse Order of Points
The option „Reverse Order of Points“ inverts the sequence of points in the polygon’s point list (dialog Geometry). Thus, the former first point becomes the new last point.
Weighting Criterion
The option „Point with max. Weight becomes Point 1“ enables to specify a criterion defining the new first point. Via the double-arrow (
) the following pre-defined parameters can be selected:
| Parameter | Remarks |
|---|---|
| x, y, z | object’s coordinates x, y, z |
| ground | ground height |
| num | number of the polygon point (counting from the first point) |
| len | 2D-polygon length |
| len3 | 3D-polygon length (considering the height z) |
| dist | 2D-distance to the first point |
| dist3 | 3D-distance to the first point (considering the height z) |
The weighting criterion will by default select the highest value of the specified parameter/s („maximum weight“). In order to select for the smallest value („minimum weight“) use the negation (e.g. „-ground“).
Example 1
Task: The building’s polygon point having the highest ground height become the new first polygon point of the buildings.
Background: When modeling buildings with terrain CadnaA defines from the first polygon point the final height of the building. So, the relative height will be attributed to the first polygon point. The subsequent polygon points the heights are defined automatically assuming the building’s edge is horizontal.
Solution: When importing building polygons the first polygon point is often defined randomly. In the picture below both buildings have a relative height of 10 m. The representation (and also the calculation result) in CadnaA of the buildings height’s is, however, different as the first polygon point of the building to the left is on the hill’s side, while for the right it is on the valley’s side.
Hill with two buildings, both having a relative height of 10 m
To modify the order of points proceed as follows:
- Click onto the white area and select Modify Objects from the context menu.
- Select the action „Modify Order of Points“ and the building for object type.
- Click OK.
- Activate on dialog Modify Order of Points the option „Point with max. Weight becomes Point 1“ and enter the parameter
groundor select it from the list provided (>>).
Point with maximum value “ground“ becomes new point 1
- Upon OK the command is executed.
Double-click onto the - in this example - building to the right and display the list polygon points. The first polygon point is now located on the hill’s side as there the highest ground height occurs.
Hill with two buildings, either with 1st polygon point on the hill’s side
Example 2
Task: The building point with the smallest ground height shall become the first polygon point.
Solution: The start-off situation is equivalent to example 1. So, first proceed in the same way.
- Select from dialog Modify Order of Points again the option „Point with max. Weight becomes Point 1“.
- Enter the parameter
-groundor select it from the list provided (>>) in edit a minus-sign in front.
Point with minimum value “ground“ becomes new point 1
- Upon OK the command is executed.
Double-click onto the building to the left and display the list polygon points. The first polygon point is now located on the valley’s side as there the lowest ground height occurs.
Hill with two buildings, either with 1st polygon point on the valley’s side