How can I change the level of the contours, triangles, etc. displayed from the terrain model?
The level of the contours, triangles, etc. of the terrain model are all governed by the Feature Definition of the terrain model. Using the delivered workspaces, right click on the terrain model and select Properties to get the Feature Definition (located at Feature). At Element>Element Template>Element_Templates_Imperial.dgnlib>Terrain, you will find the terrain feature definition. Select the feature definition and contours are under Calculated Features. For Triangles, select Element_Templates_Imperial.dgnlib>Terrain>Design_Traiangles.