The best way is to first understand how they are put together. Have a read of the manual under advanced editing and how to use XPacker. It has an description of the Complex Tree object which will help you understand the lights.
The lights are a bit simpler in heirarchy but more complicated in the Materials they use, especially the start/pit lights. rFactor is very particular about the names/animations.
A regular night light is simple enough but it's a good idea to examine the Default XPack and see how it works.
To do that:
- Extract the Default.zip XPack into a new folder, say named "MyTest".
- Move this folder into your XPacker work area (BobsTrackBuilder\XPacker\XPacks\).
You should now have the folder BobsTrackBuilder\XPacker\XPacks\MyTest and it should contain the folders CrossSections, Materials, Objects, SObjects, Textures and a couple of Description files.
- Run XPacker and load the MyTest XPack.
- Go to the Objects tab and navigate to the Roadside\Lights\Light and Post object. This is a complex object and its main purpose is to link the post and the light source together - see the Child Objects tab.
The first of the Child Objects is the Light Structure. This object is the pole and the shade; all the physical parts that will be seen all the time. It has the Purpose set to "Light" but I think it could just be set to Object and nothing would change. It's just a regular object like any other in BTB.
The second Child Object is the Light Glow. This consists of semi-transparent materials that give the "glowing" effect at night; this is the shards of light extending away from the light. This is the object that only becomes visible at night (unless you have set the "Light stays on").
The Light Glow object has a purpose of "Light Glow" which is VERY important as it flags this as being a light source. More light properties become available under the Light tab that allow you to set the position of the light, the colour and the strength. The position is where the invisible light source is placed - I say invisible because the light itself is not displayed, only its affect on other nearby objects is seen.