Lecture Notes

Return to ARC550 home page

4/26/02

• Lights
• Point light.
• An important thing to remember when dealing with point lights is to make sure the radius of the point light so that it is large enough to strike the associated surfaces.
• Light glow
• With this option off, only the faces which the light strikes are lit.  With is activated, the ‘space’ which the light passes through it illuminated.  This mimics atmospheric effects.
• Glow options-adjusts the intensity of the glow.  As it approaches 100% the glow region begins to create a zone of color equal to the color of the light source.
• If one desires a light similar to a ‘real’ light source, that is one wishes to have an object illuminated, it is easier to make an object light instead of placing a point light inside a glass object.
• To do this, pre-pick an object, select a light in the light pallet by double clicking, then select object light as the light type.  The result will be an object that glows.
• Night images.
• Set the background color to black, turn off the sun, allowing the placed light sources to illuminate the object.
• If desired, reduce the ambient light level.
• To place the sun in an accurate location.
• Double click on the light source declared as the sun.
• Select 'choose sun location'.
• Select the city desired, or input the specific month, day, time, and global location.
• Note:  north is assumed to be the positive x-axis.
• Terrain Modeling.
• To create a terrain model, one needs 1) site contours and 2) a site limit, which must be one closed line which defines the region to be modeled.
• Works best if these two items are on two separate layers (for selection purposes).
• Contours must pass entirely through the site.  (Although one which is inside the site limit, but is closed is fine).
• Incomplete lines are not acceptable.
• One can obtain contours by tracing underlays, or importing data from a surveyor.
• There are three types of models:

Mesh, stepped, and triangulated.