Creating the volume of the prism
- First copy the octagon at a distance of -50 units relative to the surface
of the wheel, which is where the base of the prism will be located. In the
Copy window, choose Translation and Lines. Since we want
to translate 50 units, enter two points that define the vector of this translation,
for example (0, 0, 0) and (0, 0, 50).
- Choose Select and select the lines of the octagon. Press ESC
to conclude the selection.

Figure 25. Selection of the lines that form the octagon
- Since the Z axis is parallel to the user's line of vision, the perspective
must be changed to visualize the result. To do this, use the tool Rotate
Trackball, which is located in the GiD Toolbox or on the mouse menu.

Figure 26. Copying the octagon and changing the perspective
- Choose Geometry
Create
Planar surface. Select the lines that form the displaced octagon and press
ESC to conclude the selection. Again, press ESC to exit the
function of creating the surfaces.

Figure 27. The surface created on the translated octagon
- In the Copy window, choose Translation and Surfaces.
Make a translation of 110 units. Enter two points that define a vector for
this translation, for example (0, 0, 0) y (0, 0, -110).
- To create the volume defined by the translation, select Do Extrude Surfaces
in the Copy window.
- Click Select and select the surface of the octagon. Press ESC.
The result is shown in Figure 28.

Figure 28. The result of the extrusion
- Choose Geometry
Create
Volume. Select all the surfaces that form the prism and press ESC.
- Again, press ESC to exit the function of creating volumes.

Figure 29. Selection of the surfaces of the prism

Figure 30. Creation of the volume of the prism
- Choose the option Render
Flat lighting
from the mouse menu to visualize a more realistic version of the model.
Then return to the normal visualization using Render
Normal.

Figure 31. Visualization of the prism with the option Render
Flat lighting.
NOTE:
In the option Color in the Layers window, the user may define
the color of the selected layer. The color of the layer is that used in the
rendering.