To Create a Drape Mass Element

Use this procedure to create a Drape mass element. A drape is useful when you are working with a conceptual model of a building site. You can create polylines and AEC Polygons at different elevations to represent topographic lines, and then drape a mass element over the polylines to show the contours of the site.

For the generated terrain surface, you can choose between a regular mesh with user-defined mesh density and mass element size, and a non-regular mesh defined by the input contour curves and points (Delaunay triangulation).

For a non-regular mesh, you can select either a rectangular mesh of user-specified size (the topography will be extrapolated from your input if the selected rectangular region is larger than the area covered by the contour curves and points), or a non-rectangular mesh whose surface size and shape are determined by the area of the input contour curves and points.

Creating a Drape mass element

1. On the Massing tool palette, select the Drape tool.

   Alternatively, you can click Home tabBuild panelBox drop-downDrape.

2. Select the polylines or AEC Polygons to represent contours, and press Enter.
3. Specify whether the source contours should be deleted after creating the drape mass element, and press Enter.
4. Specify which mesh type you want to generate.

   If you want…	Then…
   a surface with user-defined mesh density and mass element size (non-triangulated surface)	enter y (Yes) for Generate Regular Mesh [Yes/No].
   a surface defined from the input contours and points (Delaunay triangulation)	enter n (No) for Generate Regular Mesh [Yes/No].

5. If you are generating a regular mesh, complete the following steps:
   • Specify the first corner point of the mesh.
   • Specify the opposite corner point of the mesh.
   • Specify the mesh subdivisions in the X-direction.
   • Specify the mesh subdivisions in the Y-direction.
   • Enter the base thickness of the resulting mass element.
6. If you are generating a non-regular mesh, specify whether you want it to be rectangular or non-rectangular:

   If you want…	Then…
   a rectangular mesh	enter y (Yes) for Generate Rectangular Mesh [Yes/No].
   a non-rectangular mesh	enter n (No) for Generate Rectangular Mesh [Yes/No].

7. If you are generating a non-regular, rectangular mesh, complete the following steps:
   • Specify the first corner point of the mesh.
   • Specify the opposite corner point of the mesh.
   • Enter the base thickness of the resulting mass element.
   Note: If the selected mesh area extends beyond the selected contours, the topography of the resulting mass element is extrapolated from the input values.
8. If you are generating a non-regular, non-rectangular mesh, enter the base thickness for the resulting mass element, and press Enter.