Set particle opacity

You can give particles any amount of transparency. For software render particle types (Cloud, Blobby Surface, Tube), you must set a transparency attribute in the material that controls the particle object’s color. See Rendering for details. Do not add a per object or per particle opacity attribute to a software render particle type. The attribute value has no effect when you software render the scene.

For hardware render particle types, you can add a per object or per particle opacity attribute. See the procedures that follow. Note that if you add per object and per particle opacity attributes to a hardware render type, the per particle attribute controls the opacity.

To add and set a per object opacity attribute

1. Select the particle object and display the Attribute Editor.
2. In the Add Dynamic Attributes section, click Opacity.

   The Particle Opacity window is displayed.

3. Turn on Add Per Object Attribute and click Add Attribute.

   The Opacity attribute is displayed in the Render Attributes section of the Attribute Editor.

4. Set Opacity value.

   A value of 0 makes all particles in the object completely transparent. A value of 1 makes the particles completely opaque. Values between 0 and 1 create partial transparency. This attribute is keyable.

5. Turn on Shading > Smooth Shade All to see the effects of the opacity.

To add and set a per particle opacity attribute

1. Select the particle object and display the Attribute Editor.
2. In the Add Dynamic Attributes section, click Opacity.

   The Particle Opacity window is displayed.

3. Turn on Add Per Particle Attribute and click Add Attribute.

   The opacityPP attribute is displayed in the Per Particle (Array) Attributes section of the Attribute Editor.

4. Right-click the opacityPP box and choose an attribute editing technique from the pop-up menu. See Techniques for setting per particle attributes for details. Note that you cannot key this attribute or other per particle attributes.
5. Turn on Shading > Smooth Shade All to see the effects of the opacity.
   TipIf you see unexpected colors when you hardware render overlapping, colored, transparent particles, select the particle object and turn on Depth Sort in the Render Attributes section of the Attribute Editor. Maya will draw distant particles first and closer particles last. This creates accurate coloring at the expense of slower scene play.

   To eliminate the display of individual particles, add a per particle opacity attribute to the particle object, then use the Component Editor to assign the particle an opacityPP value of 0.