Modeling Terrain for Google Earth

If your model is geolocated with the Add Location feature and you want to display it in Google Earth, you may need to take a few extra steps. Here’s a quick overview of the tips and tricks that help your model looks its best in Google Earth:

• Minimize the number of faces in your custom terrain. First and foremost, only include the terrain that you really need. You find tips for minimizing geometry as you create and sculpt terrain in several of the Modeling Terrain subarticles. The tips for minimizing contour lines in Creating Terrain from Scratch are especially helpful. Also, see Sculpting and Fine-Tuning Terrain for tips on adding detail to your TIN only where you need it.
• Adjust your model’s horizontal or vertical position relative to its terrain. You want to make sure the roof and base align, and that the model is sitting flat on the 2D Location Snapshot, rather than hovering in the air or sunk into the ground. For an introduction to the 2D Location Snapshot, see Toggling Terrain Visibility.
• Create custom terrain to fill gaps. If your model is placed on rolling or sloped terrain, gaps may appear between your part of your model and the 2D Location Snapshot. To fill these gaps, create a little custom terrain painted to match the ground.

For details about positioning your model and creating custom terrain, read the following sections.

Positioning your model

Check that your model’s roof and base align and that it’s flat on the Location Snapshot layer. Misalignment happens most often in tall building models. To check the alignment, follow these steps:

1. Select Camera > Standard Views > Top.
2. Select Camera > Parallel Projection to turn off perspective.
3. See whether your model’s base sticks out unevenly from any side of the roof. In the following example, everything looks pretty straight.
4. If you notice any issues, use the Move tool () to adjust your building’s placement.

To check that your model isn’t hovering in the air or sunk in the earth, but sitting right on on the Location Snapshot, follow these steps:

1. If you see the Location Terrain layer instead of Location Snapshot, click the Toggle Terrain tool (), which switches back and forth between these two layers.
2. Use the Orbit tool () to move to a side view of your model. Or select Camera > Standard Views and select either Front, Back, Left, or Right from the submenu.
3. Check whether your model rests on the Location Snapshot. In the following figure, the park shelter is hovering over the Location Snapshot.
4. If you need to adjust your model’s vertical position, use the Move tool to move it up or down. To lock the move in the blue direction as you move geometry, hold down the Shift key or press the up arrow key.

Filling gaps with custom terrain

After you check and adjust your model’s vertical alignment, your model still might float or sink — or both, as shown in the following figure. That’s because Google Earth’s 3D terrain doesn’t always match what exists in the physical world.

To hide the gaps, put a skirt on your model. To create this skirt, you don’t need to know a thing about fashion or sewing. Just follow these steps:

1. Make sure the Location Terrain layer is enabled by clicking the Toggle Terrain tool ().
2. Make sure your model is a group or component. If not, see Grouping Geometry or Creating a Basic Component.
3. Sink the part of your model that belongs underground, such as a basement or an underground garage. Everything that belongs above ground can float for now.
4. With the Line tool (), click a bottom corner of your model, starting from the Endpoint in Group inference.
5. Click a point on your terrain to connect your building to the terrain.
   Tip: Look for the On Face in Group inference to make sure the line’s endpoint touches the terrain.

6. On your model, click a lower edge that connects to the endpoint you clicked in Step 3.
7. Click the endpoint that you clicked in Step 3 to create a third edge. A triangular face appears, as shown in the following figure.

   

8. Continue drawing triangles until the skirt is complete, as shown in the following figure.

   

9. Select the Eraser tool ().
10. Hold down the Ctrl key (Microsoft Windows) or the Option key (Mac OS X) and click any edges that you want to soften with the Eraser cursor. (Softening, Smoothing, and Hiding Geometry explains what softening edges is all about.)
11. Sample the texture on the existing terrain by selecting the Paint Bucket tool (), holding down the Alt key (Microsoft Windows) or Command key (Mac OS X), and clicking the Google snapshot.
12. Click your terrain skirt to paint the photo texture on the new faces, so that they blend with your existing terrain. You see an example in the following figure.