6.10 Extrude

Extrude is a term that describes the process of "stretching" a linear or planar object linearly into a (in most cases) third dimension to create a 3-D Solid Object from it. See the Pull command for a more graphical and WYSIWYG method of extruding.

Extrude is a powerful tool for modeling Solid Objects because extruded shapes are commonly found in modern architecture. At right, some examples of extruded shapes are shown. The original planar object is shaded and the arrows indicate the direction of extrusion.



Any existing Solid Object may be Extruded. Select the Extrude command from the Modify tab of the Ribbonbar. The Properties tab will appear allowing for entry of command parameters.



An Extrusion Distance must be entered. The default direction of Extrusion is perpendicular to the plane of the Solid Object, in the direction nearest the point of view.

To extrude in the opposite direction, specify a negative Extrusion Distance.



When Directional Extrusion is chosen, the Command Line will prompt for the base and destination points of a vector to establish the direction of Extrusion. In terms of the graphics above and at right, the base would correspond to the tail of the arrow and the destination would correspond to the head. The exact location of the chosen base and destination points is irrelevant as they only serve to indicate a direction. The base and destination points may be entered manually as well. For example, a base point of (0,0,0) combined with a destination point of (1,0,1) would result in the extrusion at right, which is in the X-Z plane at an angle of 45°.



The result of Extrusion is a single Solid Object having the same Reflectance value (taken from the original planar object) on all surfaces. Should varying Reflectance values need to be assigned, this can be accomplished by editing the Reflectance values by using the Properties command. The Grouped Solid Object can also be Exploded into its component Solids.



Extruding Background Objects follows a similar methodology as Solid Objects. Select the object to be Extruded, specify the extrusion distance in the Properties tab, and right-click or press Enter to end the command.



Lines can be Extruded to make Rectangles.



Note that the Extrusion process is the core of the behavior when executing the Room and Structure commands. Review Rooms and Structures before deciding to construct a Solid Object and Extrude it; i.e. constructing a Room or Structure may be a quicker process.