Parameters - Options
No Decay – Normally the light intensity is inversely proportional to the square of the distance from the light (surfaces that are farther from the light source receive less light than surfaces which are closer to the light). When this option is enabled, the light's intensity does not decay with distance. See the example under VRayLightSphere to see this demonstrated. This option is inactive when using the V-Ray CUDA engine.
Double Sided – When enabled, light emits from both sides of the plane. For more information, see the Single-Sided vs Double-Sided Lights example below.
Invisible – Controls whether the shape of the VRayLightRect source is visible in the render result. When this option is enabled, the light source is not visible in the rendering. When this option is disabled, if the light source is seen directly by the camera or through refractions, it appears in renderings in the current light color.
Note: The visibility of the light with respect to reflections is controlled by the Affect Specular and Affect Reflections options rather than the Invisible parameter.
Skylight Portal – When enabled, the Light Color and Intensity multiplier parameters are ignored; instead the light will take its intensity from the environment behind it.
Simple Skylight Portal – This option is available only when the Skylight Portal option is enabled. This option can speed up rendering by simplifying the process of tracing the environment for the skylight portal. When enabled, the VRayLightRect uses all the environment color, not just the color from objects behind the light. Using just the environment behind the light requires additional rays, so using the entire environment makes the rendering of portal lights faster.
Store with irradiance map – When enabled, and GI calculation is set to Irradiance map, V-Ray calculates the effects of the VRayLightRect and stores them in the irradiance map. The result is that the irradiance map is computed more slowly but the rendering takes less time. The irradiance map can also be saved for later use.
Affect Diffuse – Determines whether the light affects the diffuse properties of the materials.
Affect Specular – Determines whether the light affects the specular of the materials. This means glossy reflections.
Affect Reflections – Determines whether the light appears in reflections of materials, both perfect and glossy reflections.
Diffuse contribution – A multiplier for the effect of the light on the diffuse component.
Specular contribution – A multiplier for the effect of the light on the specular component.
Shadow Color – Controls the color of shadows for this light. Note that anything different from black is not physically correct. This option is inactive when using the V-Ray CUDA engine.
Parameters - Photon Emission
This rollout is inactive when using the V-Ray CUDA engine.
Caustics subdivs – Only used when calculating Caustics. Lower values mean more noisy results but will render faster. Higher values produce smoother results but take more time.