Importing DXF Terrain and Matched DXF Objects into WCS5 | Landscapes

Importing DXF Terrain and Matched DXF Objects into WCS5

When to use this method

As discussed in another tutorial, the best way to place a complex collection of 3D Objects is to export the WCS terrain and use it as a reference on which to model your 3D Objects. That's great if you're creating the scene from scratch, but what if you already have the entire scene in a program like AutoCAD? You'll need to export the terrain and objects as DXF files.

Before doing that, you have some work to do it the native program. I'm using AutoCAD as an example.

¤	The terrain ASCII DXF file must be made of Points, Lines, and Polylines only. Export the terrain object in an R13 or earlier format. If the lower left corner (plan view) is not at the origin, note its coordinates.
¤	All non-terrain objects (3D Objects) should be exported as a single object. This will make it easier to place them in WCS.
¤	The 3D Object should be in the 3D Face format.
¤	Experiment by exporting a simple 3D Object DXF from AutoCAD and importing it into WCS. AutoCAD 3D constructs will require additional modifications to make good DXF 3D Objects. What those modifications are will depend on how the model was created.

Note

This method will place your terrain at 0º latitude and 0º longitude.

The story thus far

The original data on which this tutorial is based came from AutoCAD. The lower left corner of the AutoCAD terrain in plan view was 2112 meters east and 18220 meters north of the origin. The goal was to import the AutoCAD terrain into WCS5, grid it, and place AutoCAD buildings on the terrain in their correct locations.

How to do it

1. Create a new project in WCS. When asked, click Yes to the Import Data question.

2. Before continuing with the Import Wizard, open the Preferences Project page and change the Latitude and Longitude to 0º. When we import the DEM, this will place its lower left corner at 0º latitude and 0º longitude.

3. Import Wizard LOAD AS page. Select Control Points if they're not already selected.

4. Import Wizard HORIZONTAL COORDINATES page. Select Arbitrary.

5. Import Wizard REFERENCE COORDINATES page. Select Place Low X,Y at Reference and check X (Lon) + to East. This tells WCS to place the lower left corner of the DXF we're importing at the reference coordinates, in our case 0,0.

6. Open an overhead camera view. Zoom into the lower left corner of the terrain, make a preview render, and check the elevation of the corner in the Diagnostic Data window.

¤	If the elevation is the same as the terrain corner point in AutoCAD, go to Step 11.
¤	If the elevation is different than the corner point in AutoCAD, the imported WCS elevation file must be imported again to shift its elevation.

7. Launch the Import Wizard again and select the DEM we just gridded.

8. Import Wizard DATA POSITIONING page. Select Change Settings.

9. Import Wizard VERTICAL EXTENTS page. Enter the elevation shift in Datum Change. This will lower all elevations. In this example, the imported terrain was 13.25 meters too high so a
-13.25 Datum Shift was entered to lower it. After import, WCS terrain elevations will match AutoCAD elevations.

10. Disable the original DEM in the Database Editor.

11. Go to the 3D Object Task Mode, select the 3D Objects category, and click the Create button. Click anywhere over the terrain in a view to place a vector for the object. We'll change its location shortly. Close the Component Gallery when it opens.

12. Load the 3D Object DXF in the 3D Object Editor.

13. Open the Vector Editor for the vector you just created. Change the X, Y and Z values to 0 in the Active Point(s) section. This will move the vector to the 'origin' of our WCS world.

14. Go to the 3D Object Editor Size & Position page and click the Move button to access the Move values. Remember the lower left corner AutoCAD coordinates I had you note before we started? Enter the negative of the west-east coordinate in the Move X box and negative of the north-south coordinate in the Move Z box.

Example

In this AutoCAD example, the terrain lower left corner point had coordinates of 2112, 18220 (meters) in AutoCAD. When the DXF terrain was imported into WCS, we reset those same coordinates to 0,0 lat/lon. The 3D Object DXF was created in the same coordinate system as the terrain so we have to move it to match the new terrain location. Moving it 2112 meters west (-2112 Move X) and 18,220 meters south (-18220 Move Z) will match the 3D Object location to the terrain. Remember that 3D Objects use traditional 3D modeling XYZ space where Y is the elevation whereas WCS world coordinates use XZY space where Z is the elevation.

15. The 3D Object should now be correctly positioned on the terrain.