Apply barn doors when you want to
create the effect of light pouring out of a half-opened door. Barn
Doors are shutters applied to a spot light’s beam. Barn
Doors are off by default; you must turn them on, then
adjust them to get the desired light spill.
To use Barn Doors
- Select a Spot Light whose manipulators
are displayed, then turn Barn Doors on
in the Attribute Editor.
- In the Light Effectssection
of the spot light’s Attribute Editor, turn on Barn Doors.
- Select Look Through Selected from
the view’s Panels menu to look through
the selected light. (The Barn Doors manipulators
are only visible in the light’s view.)
Four blue lines appear.
These lines represent a rectangular boundary for the spot light.
No light reaches the regions outside the blue line-boundaries.
- You can directly manipulate each of the
four lines with the Move tool to shift the boundaries.
(Alternatively, you can enter precise numerical values in the Attribute
Editor.)
Attributes are in degrees
measured from the spot light to the blue line-boundary. For instance,
for an 80 degree spot light, the four blue line-boundaries are 40
if the boundaries lie exactly at the spot light border.
When you use the Barn
Doors settings, the Light Shape sample changes at the
top of the Attribute Editor.
- Tweaking the penumbra value displays
a second circle. Change the value in the Attribute Editor or
click the Index Manipulator icon to
display and use the manipulator, then select Panels
> Look Through Selected to see the circle.
The region between the
two circles results in a softer illumination.
- If the penumbra value is set to 0 (the
default) and Barn Doors is on, this results
in a very hard-edged look to the lighting. With a non-zero penumbra
value, the barn door effect is a smooth illumination of the scene.
You can also verify the
illumination by looking at the Light Shape and Intensity
Sample at the top of a spot light’s Attribute
Editor. These change as you change the values for the
spot light.
- To return to the current view, select
the view from the Panel menu.