Although a Scene Ambience node is visible at the object level in the explorer, editing its value affects the ambience of the whole scene.
Scene ambience simulates a certain amount of indirect light, coming from no particular source, that is applied to all objects in the scene. It is a simple approximation of the indirect lighting that normally bounces around an environment and illuminates objects to a certain extent.
The scene ambience is not controlled by a light, but is a property applied to the entire scene. It does, however, affect the final look of directly illuminated objects to a certain extent.
The effect of ambience on the scene is to brighten or darken all objects to a certain degree. The scene ambience is multiplied with each object’s ambient area of illumination to produce the object’s final ambient component. For more information on an object’s ambient color, see Materials and Surface Shaders [Material and Shader Basics].
1. Click on the Ambient menu button in the Render toolbar to open the scene’s ambient lighting property editor.
2. Edit the scene’s ambient value as desired using the color sliders. Keep this value dark or low so as not to affect your scene’s lighting in an unpredictable way.
- If the scene ambience is set to black, nothing can alter the ambient color of an object except, of course, a light.
- For best results, ambience should be set to 0 (or close to it) in scenes with photon lighting effects like global illumination and caustics. These effects create indirect lighting, but much more realistically, so ambience is unnecessary. For more information about photon lighting, see Global Illumination and Caustics [Indirect Illumination].
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Although a Scene Ambience node is visible at the object level in the explorer, editing its value affects the ambience of the whole scene. |
Setting a Realistic Ambient Color
Perhaps the most realistic way to set a scene’s ambient color is to match a color from a rotoscoped image from the scene you use for compositing.
To set a realistic ambient color
1. Open the Ambient Lighting property editor as described above.
2. Open a Rotoscope view in any viewport and load an image or scene to be used for compositing.
3. From the Ambient Lighting property editor, click the color box to open the color editor.
4. From the color editor, select the color picker 
; the cursor changes to an eye-dropper.
5. Use the color picker to select the ambient color from the image or scene to be used for compositing. For best results, choose an ambient color you find in the shadows of an image.
6. Close the color editor to accept the chosen color as the new ambient lighting color.
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There are some color range limitations to safely output for TV or film. A true black or a full red isn’t supported by NTSC and some other formats. Also, adjusting the gamma value doesn’t alter a black color generated by a non-lit scene/object; that is, you can adjust the shadowed area of a scene without adjusting or adding lights. |
Autodesk Softimage v.7.5