Exercise: Making the Roof Height Responsive to the Path Elevation

Currently the roof height is constant in height and width even as the path goes up and down. To make it more interesting you can make it responsive to the undulation of the path. To achieve this, you replace the fixed length of the vertical line, line1, of the sections with an expression that calculates the height as a function of the desired maximum height of the roof and the height of it base point along the path.

Note: You may have already completed this exercise already as an optional step in an earlier exercise. If so, you can skip to the next exercise.

In the Graph, right click on the line1 node, and select Edit from the pop up menu. The Node Properties dialog opens.
For the Length input, edit the expression to subtract the Z value of plane1 from a fixed value. This value will be the maximum elevation of the roof in absolute Z of the baseCS CoordinateSystem. Enter Length=5-plane1.Z This will adjust the height of the roof so that it will always exactly reach the height of absolute 5 in the Z-Axis of the baseCS. This is possible because the simple equation varies the line1.Length to compensate for the ups and downs of the path.
Use the (Move node) tool to vary the initial four point’s height and position to see the roof respond.
Record User Changes into Transaction file.
Note: Additional steps could be placing a grid of components on the surface that responds to the distortions of the roof.

This completes building the roof surface. Next you will create a user defined component and populate it on the surface.