# emissiveColor The color of light this material emits. ``` var emissiveColor: CustomMaterial.EmissiveColor { get set } ``` ## Discussion With physically based rendering (PBR), you can give entities in RealityKit the appearance of emitting light. Use this property to simulate real-world objects that glow, such as objects with LEDs or computer screens. To enable light emission from a material, set [`emissiveIntensity`](/documentation/RealityKit/PhysicallyBasedMaterial/emissiveIntensity) to a value greater than zero, then specify a color (other than black) using this property. You can specify a single emissive color for the entire material, or use a UV-mapped image texture to use different colors for different parts of the entity. With custom materials, RealityKit doesn’t use [`emissiveColor`](/documentation/RealityKit/CustomMaterial/emissiveColor-swift.property) automatically to render your entity. Call `params.surface().set_emissive_color()` from your surface shader, otherwise RealityKit renders no light emission. The following example assigns a tint color to the [`emissiveColor`](/documentation/RealityKit/PhysicallyBasedMaterial/emissiveColor-swift.property) property, without a texture: ```swift self.emissiveColor = PhysicallyBasedMaterial.EmissiveColor(color: .red) ``` This next example uses a texture to specify the [`emissiveColor`](/documentation/RealityKit/PhysicallyBasedMaterial/emissiveColor-swift.property) property: ```swift if let emissiveResource = try? TextureResource.load(named: "entity_emissive") { let emissiveMap = MaterialParameters.Texture(emissiveResource) material.emissiveColor = .init(texture: emissiveMap) } ``` This Metal code shows how to access the emissive color tint in your shader functions: ```cpp half3 emissiveTint = (half3)params.material_constants().emissive_color(); ``` The following Metal code demonstrates how to sample the emissive color texture for the current fragment: ```cpp // Get the entity's primary texture coordinates. float2 uv = params.geometry().uv0(); // Flip the y-axis. You only need to do this for entities you load from // USDZ or .reality files. uv.y = 1.0 - uv.y; // Sample the emissive color texture to get the value for this fragment. auto tex = params.textures(); half3 emissiveColor = (half3)tex.emissive_color() .sample(textureSampler, uv).rgb; ``` --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)