You can produce very accurate renderings of daylight scenarios using the mia_physicalsun and mia_physicalsky shaders.

Maya automatically creates a network of required nodes and connects them to all existing renderable cameras.

To create the sun and sky effect

1. Select Window > Rendering Editors > Render Settings to open the Render Settings window, and select the mental ray renderer.
2. Click on the Indirect Lighting tab. In the Environment section, click the Create button beside Physical Sun and Sky.
3. A network of the mia_physicalsun, mia_physicalsky, mia_exposure_simple, and directionalLight nodes is created. You can view this network in the Hypershade window.
4. Tweak the attributes in the Attribute Editor of the mia_physicalsky and mia_physicalsun nodes to obtain the sun and sky effect that you desire.
   NoteUse the directional light to aim the direction of the sun. Use of the Sun_direction attribute is not recommended.

   A directional light is used to emulate the sun because the sun is infinitely far away and its scale and translation are irrelevant. Only the direction in which the light is pointing is important.

5. The sun and sky shaders should be used in conjunction with final gather. Turn on final gather in the Render Settings window. For more information, see Final Gathering.
   Tip

   • mia_physicalsky is the main node in the network.
   • The network of nodes is connected to all existing renderable cameras. If you add a new camera after the creation of sun and sky, the network needs to be updated accordingly. See To edit camera connections.
   • It is recommended that you connect an environment shader, such as mib_lookup_spherical, to the Background attribute. Use of a 2D texture may not produce the expected result.

To edit camera connections

1. In some cases, you may create a new camera in your scene after you have created your sun and sky effect. To add this new camera to the sun and sky shader network, select the Update Camera Connections button in the mia_physicalsky Attribute Editor.
2. In other cases, you may wish to detach the sun and sky shader from the renderable camera while retaining the other shader settings and connections. Select the Remove Camera Connections button in the mia_physicalsky Attribute Editor. Do not select the Delete button in the Environment section of the Indirect Lighting tab of the mental ray tabs in the Render Settings window for this purpose. The Delete button completely removes sun/sky from your scene.