How do I drape geometry onto terrain?

To drape geometry onto terrain, for example, contoured terrain imported from AutoCAD:

  1. Move the geometry so that it is positioned directly over the location on the terrain you want to drape it onto, and a little bit above it. You may need to perform several moves to get it exactly positioned; it can help to work in X-ray mode with Perspective mode turned off and using the standard Top view:
    1. Open the "Camera" menu.
    2. If "Perspective" has a check mark next to it (in other words, it is enabled), click it to turn off perspective view.
    3. Open the "Camera" menu.
    4. Point to "Standard," and then click "Top", so that you are looking straight down at the image and the terrain below it.
    5. Open the "View" menu.
    6. Click "Face Style."
    7. Click "X-ray." With X-ray mode enabled, you'll be able to see the image in relation to the terrain.
    8. Using the Move tool, position the geometry exactly where you want it to be draped.
    9. Once you have positioned the geometry, turn X-ray mode off, and turn Perspective mode back on.
  2. Select the Drape tool.
  3. Click the geometry you want to drape.
  4. Click the terrain. The outline of the geometry is draped onto it.
    Note: Occasionally, some of the line segments might not intersect with the terrain and are displayed bold. In that case, simply edit the terrain group and redraw the lines. You may also need to hide or soften any lines that are still displayed inside the draped shape so that the surface behaves like a single surface when you paint it with color or texture.

If the geometry is very large or the process takes a very long time, you can simplify the contours. For more information, click here.