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300 Chapter 18: Effects and Environments
scanline renderer. When you use standard lights
but leave Affect Indirect Only off, radiosit y and
exposure control yield results that can be quite
different from the default scanline renderer.
In general, you don’t need to turn on Affect
Indirect Only when the primary lighting for your
scene comes from photometric lights.
Exterior daylight—When on, converts colors for an
outdoor scene. Default=off.
The exterior daylight setting compensates for the extreme
intensity of an IES sun light.
Pseudo Color E x posur e Control
Rendering menu > Environment > Environment and
Effects dialog > Environment panel > Exposure Control
rollout > Choose Pseudo Color Exposure Control from the
list. > Pseudo Color Exposure Control rollout
P seudo Color Exposure Control is actually a
lighting analysis tool that provides you with an
intuitive way of visualizing and evaluating the
lighting levels in your scenes. It maps luminance
(page 3–964) or illuminance (page 3–955) values
to pseudo colors that show the brightness of the
values b e ing converted. From darkest to brightest,
the rendering shows blue, cyan, green, yellow,
orange, and red. (Alternatively, you can choose a
grayscale where the brightest values are white, and
thedarkestareblack.)Therenderingincludesthe
coloredorgrayscalespectrumbarasalegendfor
the image.
Note: You can use the Pseudo Color exposure
control with the mental ray renderer (page 3–78).
Pseudo color exposure of a scene with radiosity. Areas in red
are overlit, areas in blue are underlit, and areas in green have a
good lighting level.
If you render a scene using this exposure control,
aspecialrender element (page 3–137) named
Illuminance is created in order to obtain accurate
luminance and illuminance data.
Tip: Ifyougetafilewriteerrorwhenyoutryto
render a pseudo color image, check the path
and file name of the Illuminance element, or
thepermissionsofthePNGfilethatsavesthe
illuminance data.
Three spheres at an equal distance from a light source. The
sphere on the left has a matte material, the sphere in the
middle is glossy, and the sphere on the right is glossy but has a
much darker color.