AECbytes Tips and Tricks Issue
#6 (May 24, 2006)
Light Sources in Piranesi: Setting a Vertical
Independent Writer and Consultant
In this example, we want a vertical cone light
to project downward from the circular ceiling
light fixture onto the balcony.
This type of light is created by a Radial
Fade, whose type is 3D Line Source.
To define the light's start point, click Pick
next to Start.
Start the 3D line source at the center of the
light fixture. (Click the point, do not drag to
the end point.) Then click End
and pick an end point on the floor below the fixture.
To see the shape of this light source, uncheck
Place centre (if needed), then
click Tweak. The shape is a cylinder,
but it is probably not exactly vertical.
Press Esc to leave Tweak
mode, and click anywhere to create the light.
It might look pretty good, but it can be created
Since the light is supposed to be projected straight
down, we can use known reference points to create
the light, then move the light to its correct
location. Delete the light created earlier, and
start the process again using Radial Fade
with type set to 3D Line Source.
Click Pick for Start
and drag a vertical line to define both the Start
and End points. Drag this line
along any two points, anywhere on the model that
will define a vertical line.
Tweak the light, and drag the
radius to enlarge or shrink the cylinder.
To move it into place, move the cursor to the
centerline of the cylinder, where it becomes a
rectangular symbol. Move it to the balcony light
Reapply, and the light projects
straight down. Depending on how long your cylinder
is, the light might not make it all the way to
For the light to proceed all the way to the floor,
check Infinite line and Reapply.
Now the light goes to the floor (but not past
it). If the beam of light appears too narrow or
wide, you can always Tweak it
About the Author
Bonnie Roskes is the author of a number of books
on SketchUp, including the recent "Mastering
Piranesi: version 4" and "The
SketchUp Book: version 5." She is the founder
of F1, a
technical documentation and training company,
which does project work for several CAD/CAM companies
such as updating manuals, online help, and creating
tutorials. In addition to SketchUp, she has authored
books on OneCNC, and Piranesi (soon-to-be released).
Bonnie has a BS and MS in structural engineering,
and worked for several years in bridge design
and analysis before moving to tech writing. She
can be reached at: email@example.com.
Tricks > Setting a Vertical Cone in Piranesi