The following is a sample
workflow for creating light fog using mental ray for Maya.
- First, create a spot light in your scene.
Light fog is supported with point lights or spot lights.
- Under the spotLightShape node, under Light
Effects, click the Map button.
The lightFog node is created.
- Scale your spot light to create the fog
effect that you desire.
- Under the spotLightShape section, expand
the mental ray section, under the Custom Shaders section,
click on the Map button beside the Light Shader field
and select a mental ray light shader, for example, mib_light_spot.
- Under the mib_light_spot node, ensure
that Attenuation is on.Set the Start value
to specify the distance from the light where attenuation begins.
Set the Stop value to specify the maximum
distance reached by the light. Increase the cone value for a more
subtle fog effect.
- Under the coneShape node, Render
Stats section, enable Volume Samples Override and
increase the number of Volume Samples for
better quality. Enable
Depth Jitter if
necessary.
- To modify the color of your fog, you
can change the Color attribute within the
mib_light_spot node. Alternatively, you can click on the Map button beside
the Color attribute and map the
color attribute to the mental ray mib_cie_d node. Under the mib_cie_d
node, increase the temperature. A value of 4000 gives a sunset feel.
For a more blue toned fog, increase the temperature.