Rendering with Interior Lights
	This method will detail how to use artificial lighting within your render scenes.
Part of	VRay
Part Type	Method
Screenshot

Introduction to V-Ray Interior Lighting

V-Ray has six types of lights . For interior lighting, Point Lights and Spotlights are usually used because they provide more direct, localized light, much like a lightbulb. These lights are mostly used in an enclosed interior space or an interior space at night, which makes their shadows especially important. For exterior light that illuminates an interior space, rectangular light is used because the angle of the light does not matter.

Using Point Light and Spotlight

Remember that the shadows for Point Light and Spotlight are very much affected by the distance from an object, so it will take longer time to adjust these two lights. To adjust the light's properties, select the light, use the Properties command, and select "Light" from the drop down menu.

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  Point Light Properties

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  Spotlight Properties

For these lights, adjusting the Decay affects how much light is emitted. Changing the Decay using Inverse or Inverse Square from the drop down menu affects Decay dramatically. When using Inverse or Inverse Square, the light's multiplier must be increased.

Using Rectangular Lights

Rectangular Light creates smooth, uniform light because the angle of the light does not matter. Unlike the Spotlight, with Rectangular Light you don’t have to worry about the angle of the light. It allows reflective material to bounce the light around the scene. Below are some important characters about Rectangular Light.

Size does matter: the size of the Rectangular Light has an effect on its intensity.

Shadow changes according to the size: a Larger Rectangular Light spreads out to a larger area, so the shadow is not as clear as you will get from a smaller Rectangular Light.

There is an Invisible option in Rectangular Light. It allows the light visible or invisible from the render image. The default setting for Rectangular Light has the Invisible option unchecked. If you see any unusual dark shadow in your rendered image, please check if your camera is blocked by the Rectangular Light in the scene.

You can tell the direction of the light from the short line on one side of the Rectangular Light. Rotate the light and you can change the direction of the light.

The Double Sided option can turn the light direction from one side to both side of the light. Move the light away from the floor or wall to avoid any black out area. Double Sided option is often used for a big interior scene. It helps to light up the space without using too many lights. The default has the Double Sided option unchecked. Of course, if you check and Invisible option, you will not see the light in the three images below.

Change the light intensity as desired. Make sure shadows are enabled.

Creating Emissive Materials

Emissive Materials are a key step to producing a night render.

Click on the + next to the Cup_Green to pull down the layers. Right click on Emissive Layers and select Add new layer. You will see the new Emissive layer added to the right side.

Open the Emissive menu. Default settings: the color to white, intensity to 1 and Transparency color to black. Click on Material Preview and you will see a completely white material ball.

Self-illuminated material can make the object become a lightsource itself. It does not limit to a certain shape like a regular light type does. Every part of the object can be illuminated and used as a lightsource.

The default intensity setting will be 1, try different intensity values, you may have to try numbers in the double digits.

Post-processing

Rendering with alpha contribution turned on makes it easy to select the background later in Photoshop .