GeoVRML使得对室外场景使用VRML更加简单，例如海拔图。

With GeoVRML it became much easier to use VRML for outdoor scenes, such as mapping elevations.

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最常用的办法是先定义海拔图，然后将海拔达到海平面的地方定义为海岸线。

The most realistic approach would have been to define elevation first, and then define the coastline to be where the elevation reaches sea level.

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这是一幅由美国地形勘测出来的地形图，基本上，所有海拔等高线在一块陆地上。

So, a topographic map, this one from the US geological survey shows you, basically, all the level curves of an altitude function on a piece of land.

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