To enhance the scene in the graphics window, you can change the color, visibility,
and other display properties
of each geometric object in the scene. You can specify different colors for displaying the edges and faces of a grid object to show the underlying mesh (edges) when the faces of the grid are filled and shaded. You can also make a selected object temporarily invisible. If, for example, you are displaying the entire grid for a complicated problem, you can make objects visible or invisible to display only certain boundary zones of the grid without regenerating the grid display using the
Grid Display panel. You can also use the visibility controls to manipulate geometric objects for efficient graphics display or for the creation of animations. These features, plus several others, are available in the
Display Properties panel (Figure
Figure 28.5.2: The
Display Properties Panel
To set the display properties described above, select one or more objects in the
Names list in the
Scene Description panel and then click the
Display... button to open the
Display Properties panel for that object or group of objects.
There are several ways for you to control the visibility of an object. All visibility options are listed under the
Visibility heading in the
Display Properties panel.
To make the selected object(s) invisible, turn off the
Visible option. To "undo'' invisibility, simply turn the
Visible option on again.
To turn the effect of lighting
for the selected object(s) on or off, use the
Lighting check button. You can choose to have lighting affect only certain objects instead of all of them. Note that if
Lighting is turned on for an object such as a contour or vector plot, the colors in the plot will not be exactly the same as those in the colormap at the left of the display.
To toggle the filled
display of faces for the selected grid or surface object(s), use the
Faces option. Turning
Faces on here has the same effect as turning it on for the entire grid in the
Grid Display panel.
To turn the display of outer edges on or off, use the
Outer Faces option. This option is useful for displaying both sides of a slit wall. By default, when you display a slit wall, one side will "bleed'' through to the other. When you turn off the
Outer Faces option, the display of a slit wall will show each side distinctly as you rotate the display. This option can also be useful for displaying two-sided walls (i.e., walls with fluid or solid cells on both sides).
To turn the display of interior and exterior edges of the geometric object(s) on or off, use the
To turn the display of the outline of the geometric object(s) on or off, use the
Perimeter Edges check button.
To toggle the display of feature lines (described in Section
28.1.1), if any, for the selected object(s), use the
Feature Edges option.
To toggle the display of the lines (if any) in the geometric object(s), use the
Lines check button. Pathlines, line contours, and vectors are "lines''.
To toggle the display of nodes (if any) in the geometric object(s), use the
Nodes check button.
Once you have set the appropriate display parameters, click the
Apply button to update the graphics display.
Controlling Object Color and Transparency
Display Properties panel also lets you control an object's color and how transparent it is. All color and transparency options are listed under the
To modify the color of faces, edges, or lines in the selected object(s), choose
node-color in the
Color drop-down list. The
Blue color scales will show the RGB components of the face, edge or line color, which you can modify by moving the sliders on the color scales. When you are satisfied with the color specification, click
Apply to save it and update the display. The ability to set the colors for faces and edges can be useful when you wish to have a filled display for the grid or surface, but you also want to be able to see the grid lines. You can achieve this effect by specifying different colors for the faces and the edges.
To set the relative transparency of an object, select
face-color in the
Color drop-down list. Move the slider on the
Transparency scale and click the
Apply button to update the graphics display. An object with a transparency of 0 is opaque, and an object with a transparency of 100 is transparent. By specifying a high transparency value for the walls of a pipe, for example, you will be able to see contours that you have displayed on cross-sections inside the pipe. (This feature is available on all platforms when the software
buffer is used for hidden surface removal, but if your display hardware supports transparency, it will be more efficient to use the hardware
buffer as the hidden surface method instead. You can select these methods in the
Display Options panel, as described in Section
If you save a hardcopy of a display with transparent surfaces, you should
not set the
File Type in the
Graphics Hardcopy panel to