Adding Noise to Light
Maya 2012 Tutorial
How to Add Light Noise in Maya
By creating a grayscale RGB image in Photoshop you can choose which areas will receive more light. The light areas of the map are brighter and the black areas are darker.
Open a new 500 pixel by 500 pixel document in Photoshop with a white background. using the default colors, choose Filter > Render > Clouds. Blur the image by selecting Filter > Blur > Gaussian Blur. Save the image as a jpg file in your Maya project's sourceimages folder.
Open your Maya project with a few objects in the scene.
Add one spotlight (Create > Lights > Spot Light). Position the light with the Move Tool so it illuminates the scene. Press the t key to access the light's manipulator.
Soften the edges of the light by adjusting the Dropoff and Penumbra Angle in the light's Attribute Editor.
Click the checker-box next to the Intensity slider. In the Create Render Node box, right-click the File icon and choose Create Texture. This creates a file texture that is UV mapped to the object.
In the Attribute Editor, under file tab, click the folder icon next to the image name and navigate to find your jpg file. Render your image. You may need to adjust the light's cone angle to see the effects.