General Parameters Rollout (Photometric Lights)

This General Parameters rollout is displayed for photometric lights. These controls turn a light on and off, and exclude or include objects in the scene. They also let you set the type of light distribution.

On the Modify panel, the General Parameters rollout also lets you control the light’s target object and change the light from one type to another.

The General Parameters rollout also lets you turn shadow-casting on or off for the light, and choose which type of shadow the light uses. See Shadow Types and Shadow Controls and Shadow Parameters.

Procedures

To turn a light on and off:

To have a light cast shadows:

The light will now cast shadows when you render the scene.

Left: With Spotlight distribution, the projection cone can truncate shadows.

Right: With Uniform Spherical distribution, the light casts complete shadows.

To have a light use the global settings for shadows:

To set a light's shadow parameters individually:

Tip: When you render a scene, you can turn rendering of shadows on or off.

To cast area shadows:

To cast advanced ray-traced shadows:

To cast shadow-mapped shadows:

  1. On the General Parameters rollout, choose Shadow Maps from the drop-down list.
  2. Go to the Shadow Map Parameters rollout.
    • Use the Size spinner to set the size of the shadow map.
    • Use the Bias spinner to adjust the shadow offset, if necessary.
    • Use the Sample Range spinner to create a soft-edged shadow.

To cast ray-traced shadows:

    Ray-traced shadows are generated by tracing the path of rays sampled from a light source. Ray-traced shadows are more accurate than shadow-mapped shadows.

  1. On the General Parameters rollout, in the Shadows groupo, choose Ray-Traced Shadows from the drop-down list.
  2. Use controls on the Ray-Traced Shadow Parameters rollout to adjust the shadow offset, if necessary.

To keep an object from casting shadows:

  1. Select the object.
  2. Right-click the object to display the quad menu, then choose Properties from the Transform (lower-right) quadrant.

    The Object Properties dialog is displayed.

  3. Turn off Cast Shadows, and then click OK.

    Now when you render the scene, the object casts no shadows.

To make an object not receive shadows:

  1. Select the object.
  2. Right-click the object to display the quad menu, then choose Properties from the Transform (lower-right) quadrant.

    The Object Properties dialog is displayed.

  3. Turn off Receive Shadows, and then click OK.

    Now when you render the scene, the object receives no shadows.

    Note: You can also prevent objects from casting shadows by excluding them from a light.

Interface

Light Properties group

On
(Both Create panel and Modify panel) Turns the light on and off. When On is on, shading and rendering use the light to illuminate the scene. When On is off, the light is not used in shading or rendering. Default=on.

In viewports, the interactive renderer shows the effect of turning lights on or off.

Targeted
When on, the light has a target. When off, you aim the light using transforms. This toggle lets you change the light from a target light to a free light, or vice versa.
Target Distance
Shows the target distance. For a target light, this field simply displays the distance. For a free light, you can enter a value to change the distance.

Shadows group

On
Determines whether the current light casts shadows or not. Default=on.
Use Global Settings
Turn on to use global settings for shadows cast by this light. Turn off to enable individual control of the shadows. If you choose not to use the global settings, you must choose which method the renderer will use to generate shadows for this particular light.

When Use Global Settings is on, the shadow parameters switch over to show you what the global settings are. This data is shared by every other light of this class. When Use Global Settings is off, the shadow parameters are specific to that particular light.

Shadow Method drop-down list
Determines whether the renderer uses shadow maps, ray-traced shadows, advanced ray-traced shadows, or area shadows, to generate shadows for this light.

The “mental ray Shadow Map” type is provided for use with the mental ray renderer. When you choose this shadow type and enable shadow maps (on the Shadows & Displacement rollout of the Render Setup dialog), shadows use the mental ray shadow-map algorithm. If this type is chosen but you render with the default scanline renderer, no shadows appear in the rendering.

Note: When shadow maps are enabled and the shadow map type is Shadow Map, the mental ray renderer attempts to translate the shadow map settings into comparable settings for mental ray shadow maps. (The results might not be what you expected.) In all other cases, the mental ray renderer generates ray-traced shadows.

Each shadow type has its particular controls:

Tip: Use ray-traced or advanced ray-traced shadows when you want shadows cast by opacity-mapped objects. Shadow-mapped shadows don't recognize the transparent portions of the mapping, and as a result they don't look convincing.
Exclude button
Excludes selected objects from the effects of the light. Click this button to display the Exclude/Include dialog.

Excluded objects still appear lit in shaded viewports. Exclusion takes effect only when you render the scene.

Light Distribution (Type) group

[drop-down list]
The light distribution drop-down list lets you choose the type of light distribution. There are four options:
Topics in this section
Parent topic: Photometric Lights