Spot Lights and Mental Ray
Maya 2012 Tutorial
How to Add Mental Ray Spot Lights in Maya
Light from a spot light radiates from a single point, then fans out in a cone pattern towards your scene. You can choose between a standard spot light or an area light in the light's Mental Ray options.
By selecting the area light option, you still have control over the light's Cone Angle and Dropoff.
Add a polygon cylinder to the stage by choosing Create > Polygon Primitives > Cylinder.
Add a floor object to the stage by choosing Create > Polygon Primitives > Plane.
Using the Scale tool (e key), enlarge the plane so it is at least four times larger than the cylinder.
In the front view, use the the Move tool (w key) to place the cylinder on the plane.
Click the Render Settings icon to open the Render Settings panel. Choose Render Using: Mental Ray.
Click the Quality tab and choose Quality Presets: Production.
Add a spot light to the scene by choosing Create > Lights > Spot Light.
With the light selected, press the t key to access the light's manipulator. Use the Move tool (w key) position the light above and to the side of the cylinder. Move the light's aim point to the cylinder.
Select the light, open the Attribute Editor and open the Shadows section, Raytrace Shadow Attributes sub-section.
Click the Use Raytrace Shadows checkbox.
Increase the Light Radius to 3 and the Shadow Rays to 30. Increasing the Light Radius softens the shadow edges.
Open the Mental Ray section, Area Light sub-section and click the Area Light checkbox.
Click the perspective view and render your image by clicking the Render Current Frame icon. If the image is too dark or over-exposed, select the light and change the Intensity value in the Attribute Editor.
Adjust the light's Cone Angle and Dropoff to soften and fine tune the light. Render another image to view the changes.
Depth Map Shadows
In addition to Raytrace Shadows, you could also use Depth Map Shadows. For more information, see topic, Depth Map Shadows.
Improving the Light Edges
If your light edges appear a bit ragged, try increasing the High Samples values in the light's Mental Ray, Area Light section of the Attribute Editor.
Can't Find Mental Ray?
If Mental Ray doesn't appear in the Render Settings, Render Using: menu, choose Window > Settings/Preferences > Plug-in Manager. Make sure Mayatomr.bundle is loaded.