Create a Toposurface

Create a toposurface by placing points, by using imported 3D contour data, or by using a points file.

  1. Open a 3D view or a site plan view.
  2. Click Site tabModel Site panel (Toposurface).

To create the toposurface by placing points

    By default, the Place Point tool on the ribbon is active.

  1. On the Options Bar, set a value for Elevation.

    The points and their elevations are used to create the surface.

  2. Next to the Elevation text box, select one of the following:
    • Absolute Elevation. Points display at the specified elevation (from the Project Base Point). You can place points anywhere in the active drawing area.
    • Relative to Surface. Allows you to edit an existing toposurface by placing points on it at the elevation you specify. To use this option effectively, you may want to work in a shaded 3D view.
  3. Click in the drawing area to place points. If needed, change the elevation on the Options Bar as you place additional points.

To use imported 3D contour data

    You can automatically generate a toposurface based on 3D contour data imported in DWG, DXF, or DGN formats. Revit LT analyzes the data and places a series of elevation points along the contour lines.

    Work in a 3D view for this procedure.

  1. On the Modify | Edit Surface tab, click Tools panelCreate From Import drop-down (Select Import Instance).
  2. Select the imported 3D contour data in the drawing area.

    The Add Points from Selected Layers dialog displays.

  3. Select the layers to which you want to apply elevation points, and click OK.

To use a points file

    A points file is typically generated by a civil engineering software application. The file provides contour data using a regularized grid of elevation points.

    Learn more

      The points file must contain x, y, and z coordinate numbers as the first numeric values in the file. The file must also be in a comma-delimited file format (a CSV or TXT file). Additional information in the file (such as a point name) is ignored. Any additional numeric information for a point must occur after the x, y, and z coordinate values. If the file contains 2 points with the same x and y coordinates, Revit LT uses the point with the largest z value.

  1. Click Modify | Edit Surface tabTools panelCreate From Import drop-down (Specify Points File).
  2. In the Open dialog, navigate to the location of the points file.
  3. In the Format dialog, specify the units used to measure the points in the points file (for example, decimal feet or meters), and click OK.
  4. Revit LT generates points and a toposurface from the coordinate information in the file.

Note: To improve system performance related to surfaces with a large number of points, simplify the surface.