An object that defines the color emitted by each point on a surface.
- iOS 8.0+
- macOS 10.8+
- Mac Catalyst 13.0+Beta
- tvOS 9.0+
- watchOS 3.0+
You can use an emissive map texture to simulate parts of a surface that glow with their own light. SceneKit does not treat the material as a light source—rather, the emission property determines colors for a material independent of lighting. (To create an object that appears to glow, you may wish to combine a geometry with an emissive map and additional
SCNLight objects added to the scene.)
By default, the emissive property’s
contents object is a black color, causing the property to have no visible effect. Setting the emissive property’s contents to any solid color adds a uniform color to the material independent of lighting. To create a selective glow effect, set the property’s contents to an image or other texture-mapped content whose glowing areas use bright colors and whose other areas use darker colors. In the darker-colored portions of the emissive map (and portions with reduced opacity), the other visual properties of the material contribute to its appearance under scene lighting.
The figure below shows a material (with a texture for its
diffuse property) before and after providing an emissive map image.