Make Light Source Visible
Maya 2012 Tutorial
How to Make Light Source Visible in Maya
As you add lights to your scene, the scene's objects become illuminated. You would think that if you pointed a spot light directly at the camera, a big bright circle would appear in your rendered image. In the Maya world we see the effects of the light, but we don't actually see the light.
The lights can be modified so we see the effect of the light and also the light itself.
Add a spot light to the scene by choosing Create > Lights > Spot Light.
Use the Rotate (e key) tool to rotate the light so it is pointing directly at the camera.
With the light selected, open the Attribute Editor.
Open the Light Effects section and click the checkbox to the right of Light Glow. This adds an Optical FX node to the light's Glow.
In the Optical FX panel, open the Optical FX Attributes section and the Glow Attributes section.
Adjust the sliders in the two sections to set the number of stars, intensity, spread and noise.
The color can be set by clicking the Color rectangle.
Make your adjustments, then render your image with the Maya Software render setting multiple times as you perfect the light glow.
Adding a Halo to the Light
The section below Glow Attributes gives you access to the light's halo settings. To activate the halo, choose one of the halo options from the Halo Type menu at the top of the panel.
How About Mental Ray?
Unfortunately, the Optical FX node doesn't work with Mental Ray. For Mental Ray you might consider adding your glow effects with a compositing software such as After Effects.