Overlay Toolbox
The Overlay toolbox is used to import an overlay
contained in either an ESRI Shapefile or a DXF file.
To import an overlay:
- If the Overlay toolbox is not visible, display it by clicking
the Toolbox menu and selecting Overlay.
- Click the File tab.
- Select the Type of file (ESRI Shapefile or DXF file) to be imported.
- Click the Browse button and navigate to the
file you want to import. Double click the file.
- Click the Control tab.
- Enter the following information:
- X0 and Y0 are the x and y coordinates in the overlay file
(that is, the Shapefile or DXF file) of the point that coincides with
the lower left corner of the grid, when the grid is viewed from directly above.
- Scale is the conversion factor that converts the length
unit used in the overlay file to the length unit of the model
grid. For example, if the overlay file data are in meters,
and the grid is in feet, then "scale" should be 3.2808.
- Angle is the angle in degrees to rotate the overlay.
A positive value cause rotation in the clockwise direction.
- Next, select either:
- Flat : The overlay is displayed on a flat plane, or
- Drape : The overlay is displayed on the top of the grid.
- If you select Flat then:
- Enter a value for Elev, which is the elevation (in length
unit used by the grid) of the plane on which the overlay is displayed.
- If you check the Trim option, the overlay will be trimmed
so that any portion outside the grid (when viewed from directly
above) is removed. If you activate the subgrid (using the
Grid Toolbox), then the overlay will be trimmed to the subgrid.
- If you uncheck the Trim option, the entire overlay will be
displayed. (Even if you activate the subgrid, the overlay will
not be trimmed.)
- If you select Drape then:
- The Trim option is automatically turned on and cannot be
turned off. This is necessary because the program doesn't know
how to drape the overlay for those portions outside the grid.
Therefore, any portion of the overlay outside the grid (or subgrid)
is removed.
- You may want to raise the overlay slightly above the top of
the grid. This can be done by specifying the drape gap.
When the drape gap is zero, the overlay is exactly on the top
surface of the grid. If you set the drape gap to 1.5, the overlay
is 1.5 length units (whatever length unit used in the model) above
the top surface of the grid. (In solid display, the overlay
should be slightly above the top of the grid so that the grid
does not partially cover the overlay.)
- If desired, select Crop:
- If the you click the Crop option, portions of the overlay are removed so that the overlay appears only above the cropped solid.
- Click the Apply button.