The default value is elevation in which case elevation of the corners of each triangle is used for shading.
Slope
Use the amount of slope of each triangle. This can be measured in degrees or in percent slope.
Aspect
Use the aspect (direction of slope in degrees) of each triangle.
Light Source
Triangles will be shaded based on their slope in relation to the direction of light source.
Shading Ranges
Autogen
This option activates a dialog box allowing you to automatically generate a series of ranges based on start and end values and corresponding colors.
Add
Allows you to change the range and format for an interval.
Modify
Allows you to change the range and format for an interval.
Remove
Deletes an interval.
Light Source
These options are only available if you have selected the Light Source method of shading.
The angle formed by the slope of the triangle and the azimuth and declination of the light source will be used to compute the amount of shading to apply to the triangle. Triangles that are perpendicular to the direction of the light source will be shaded in full color. Triangles that are sloped 90° from the direction of the light source will be shaded in opposite color.
Azimuth (degrees) (from light source)
This is the direction that the light source is coming from.
Declination (degrees)
This is the amount of tilt of the light source ray. 0° would be perfectly horizontal and 90° would be perfectly vertical.
Backface Color
Any triangles that are sloped greater than 90° from the direction of light source with be shaded with the backface color. Pressing the + button will pop-up the Custom Color Dialog.
