In part 3 of the tutorial, you use the Toposolid tool to create a site and add fill with a building pad based on the exterior walls of the model.
This video demonstrates the following:
To create context for the project, you can use the Toposolid tool to add a site. Because visibility may be turned off for the toposolid category in the standard floor plan view, you will want to open a site plan view so the toposolid will be visible once it is created.
Located on the Site tab of the ribbon, the Toposolid tool is modal, meaning that when the tool is selected, the ribbon displays a contextual tab providing the tools you need to create the toposolid. To exit this mode, you must click either Finish or Cancel. You will create the toposolid by first sketching the boundary of the site. Select the Rectangle tool from the draw panel and sketch a rectangle around the building. Now create a void area for the building. Select Pick Walls from the Draw panel and clear Extend into wall on the Options bar. Hover over one of the exterior walls and press Tab to select the chain of exterior walls. Be sure the sketch is on the interior face of the walls. If it is not, use the flip control to change where the sketch lines are located. On the Type Selector, select Building Terrain toposolid type and click finish.
With the toposolid still selected, click Add Point on the Shape Editing panel. Set the offset value to 2500 and place points representing this elevation on the site. Change the elevation to 1000 and add more points. Now click Modify Sub Elements to change the elevation of a boundary. Select the right boundary of the site, use the in canvas control to set the boundary edge to -500. Click Modify to complete the toposolid. A toposolid can also be created from imported CAD files that include 3D contour information, or from a points file which can be generated by certain civil design applications.
Now create fill and add a floor to the model. First, create another toposolid for the fill beneath the floor. On the ribbon, click Toposolid. Select Pick Walls from the Draw panel and clear Extend into wall on the Options bar. Hover over one of the exterior walls and press Tab to select the chain of exterior walls. Again, be sure the sketch is on the interior face of the walls. If it is not, use the flip control to change where the sketch lines are located. On the Type Selector, select Pad Fill toposolid type and set the Height Offset From Level parameter to -150, then click finish.
Add a floor to the model using a similar technique as the toposolid. On the Architecture tab select Floor. Select Pick Walls from the Draw panel and clear Extend into wall on the Options bar. Hover over one of the exterior walls and press Tab to select the chain of exterior walls. If the sketch lines are on the interior face of the walls, click finish.
The toposolid can be seen in a 3D view. Finally, on the View Control Bar, you can apply a shaded or realistic visual style to the view to get an idea of what the building will look like.