I am having a problem getting my artificial lights to appear in a rendering where the sky is on
We don't seem to have a good default balance between illumination from the sun and sky and illumination from artificial lights.
With IRender nXt you can use Lighting Channels to quickly increase the intensity of the lights, or decrease the intensity of the sky.
With nXtRender or ArielVision, the easiest way is to increase the intensity of the lights and/or to decrease the intensity of the sun/sky.
You will need to experiment with some settings such as these:
Here is a scene with one 75W light inside a room with the sky on and visible:
Here I used the right click - override light intensity to make the light 10X brighter:
Here I made it 100X brighter
You can also make the sun less bright. (We get the sun intensity from "LIght" setting on the SketchUp Shadows Window.
Here I made the light 10X brighter, and set the sun/sky "Light" factor to 10 rather then 77
There is a setting in IRender nXt (but not nXtRender, or currently ArielVision) which lets you change the balance between artificial lights and the sun and sky or ambient light with a slider bar.
We have modified it slightly and placed it in ArielVision as well (in the next version we release).
Setting it to its new default value of 60, and placing 2 75W point lights in a shed produced an acceptable result. If four tour own models you need more or less artificia light to be visible, you can increase the wattage of the lights, or change this slider.
Light Balance on Presets Tab for IRender nXt and ArielVision
2 75W lights - Light balance set to default (60)