nXtRender Lighting Channels
Lighting Channels allow you to adjust many aspects of the lighting in your rendered image in real-time, after the rendering has been produced. This is accomplished by allowing you to create up to 8 lighting "channels" in the image. Each light source in the drawing, including the sun and sky, can be assigned to a channel. Once this image is rendered and saved, each channel can be individually scaled in the Image Editor . For example, using this capability, you can produce day and night interiors with a single rendering. The following five steps are necessary to produce and manipulate a multi-channel image:
- You must tell nXtRender how many channels you want. Go to Lighting->Advanced->Channels and set the number desired from 1 to 8. Each additional channel you add requires an additional 12 bytes per pixel internally. This is a lot of memory, particularly for high resolution renderings. It may not be possible to complete your rendering on a 32 bit system.
- You must turn on all of the participating lights. Lights which are off will not contribute to the image and will not be scalable. Because you are rendering with more lights, it may take a little longer. For example, to create an interior image which contains both natural and artificial lights:
- Select the Interior Daylight preset.
- Select Lighting->Advanced->Lights->On
- You must tell each light source which channel it belongs to. By default, Sun and Sky are set to channel 0, artificial lights to channel 1. There are controls for each light source, including sun and sky. Valid channels are 0-7.
Lighting Channel Names
Lighting Channel Names make it easier to know which channels you are modifying in the nXtImage Editor.
Right click on a light, select Properties, The type in a name, after, or instead of a channel number.
Adjusting Lighting Channels
After rendering, you can modify the intensity of lights in each channel by clicking Channels in the rendering window.
As you adjust the channels, the tone-operator will compensate. All of the tone mapping controls and rules still apply. For example, if you're trying to do a night and day exterior using the same rendering, you will almost certainly need to adjust the tone-op brightness down for the night time scene.