Material Editor > mental ray Connection rollout > Click a shader button. > Material/Map Browser > Pick a mental ray shader that returns multiple values.

Material Editor > Shader controls > Click a shader button. > Material/Map Browser > Pick a mental ray shader that returns multiple values.

Material Editor > DGS material > Click a shader button. > Material/Map Browser > Pick a mental ray shader that returns multiple values.

Material Editor > Shader controls > Click a shader return parameter button (to the right of the main shader button).

Note: The mental ray Connection rollout is available in the Material Editor only if you have enabled the mental ray extensions by using the mental ray Preferences panel. In addition, shaders don't appear unless the mental ray renderer is the currently active renderer.

Some mental ray shaders return multiple values. If you choose one of these, a Connect Parameter To Shader dialog appears. Choose one of the return values in the list, and then click OK.

Important: UV Coordinates and XYZ Coordinates are the only shaders with multiple return values provided with 3ds Max. You might encounter multiple return values in shaders provided with other shader libraries or custom shader code.

The components for some mental ray materials and shaders can be assigned other shaders. For these components, the main shader button is accompanied on the right by a small button. If no shader is assigned, or the shader assigned has only a single return value, the button is disabled and shows a dot in the middle. If the shader assigned can return multiple values, text appears in this button, and a tooltip shows the parameter name. Clicking the button displays the Connect Parameter To Shader dialog, allowing you to change the parameter being used.