V-Ray lights are designed specifically to work with V-Ray and optimize its features.

 

Overview


While you can use Houdini standard lights with V-Ray, V-Ray includes a set of lights designed specifically for rendering with the V-Ray engine.

  • Area lights shine from a light source contained within a specified area or boundary. There are several types of Area lights.
  • A Sun light simulates the sun, creating a single bright light for daytime exterior and interior scenes.
  • Photometric lights use IES files to determine the shape of the light cone and light falloff.
  • Mesh lights turn polygon objects into lights that emit both direct and indirect illumination.

Note: Using V-Ray lights and V-Ray materials within the Houdini scene will produce a more accurate lighting solution than using standard Houdini lights and materials.

 

 


 

UI Path: ||obj Network|| > V-Ray > Light

 

 

 

Light Icons at a Glance


 

 

Light Types


The  following light types can be created with V-Ray for Houdini:

Ambient Light


Ambient light permeates a scene and illuminates from all angles equally without providing contrast. For more information, see V-Ray Ambient.

Directional Lights 


The V-Ray Directional Light can create light sources that cast parallel light rays in a single direction. For more information, see V-Ray Direct.

Dome Light


A dome light (also considered an area light) creates light within a dome or spherical shape to create a traditional global illumination setup. This Light is frequently used to load HDRI environment images. For more information, see V-Ray Dome.

Photometric Lights


Photometric lights are designed to simulate a light source's distribution pattern exactly as they behave in real life by loading and using an IES (Illumination Engineering Society) file. An IES profile contains details about the light's behavior, such as how the light passes through fresnel lenses, its intensity, and its and falloff. For more information, see V-Ray IES

Mesh Lights 


The VRayLightMesh can create light sources that have volume and shape defined by geometry in the scene, without the need to use self illuminated objects and global illumination. For more information, see V-Ray Mesh Light

Omni or Point Light


The VRay Omni Light is a V-Ray specific light that can be used to create physically accurate lights that casts rays in all directions from a single source. For more information, see V-Ray Omni.

Rectangle Lights


The VRayLightRect, also known as the V-Ray Rectangle light or an "area light" is a planar light source with the shape of a rectangle or circular disk. Rectangle lights are useful for simulating man-made light sources in an interior environment, such as lamps. A rectangle light can have any one of two different shapes: plane or disc.  For more information, see V-Ray Rectangle.

Light Sphere


The VRayLightSphere is a VRay Light object in the shape of a sphere, casting light outward in all directions. For more information, see V-Ray Sphere

Spot Light


The V-Ray Spot Light is a V-Ray specific light source plugin that can be used to create a physically accurate light that directs a narrow beam of light with falloff. For more information, see V-Ray Spot.

Sun and Sky System


A Sun light is a spherical light source placed at a specific location which simulates the sun in the sky. A Sun light has some unique qualities:

  • Sun light rays that strike the scene objects are treated as parallel to one another regardless of how far the Sun object is placed from the scene objects, producing the parallel shadows that our own sun creates.
  • A Sun light is designed to be used with global illumination; when the light bounces around the scene, the resulting rendering looks very much like sunlight in real life.
  • A Sun light can work in conjunction with a Sky environment background to provide realistic lighting and coloring for the scene when used with GI. Often, Sun/Sky is the only lighting setup needed in the scene to produce a photo-real rendering.
  • The Sun/Sky combination is suitable for an exterior scene, or for an interior scene with windows or other openings through which the light comes.

For more information, see V-Ray Sun

 

Using Textures with Lights


V-Ray Lights have several parameters that make use of textures. The example below illustrates how a texture is specified for the Dome Tex parameter of a V-Ray Dome. To do this, first create a V-Ray Material node inside a shop network. Inside the V-Ray Material context, create a V-Ray Image Texture | TexBitmap node to specify the texture. Then in the V-Ray Light, specify the Image Texture node in the desired texture parameter (e.g. Dome Tex).

 

 

 

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