Lighter2 is one of Realitools2's most versatile plug-ins, but it's power also may lead to some confusion over what it actually does. The best way to think of Lighter2 is to think of it not just as one plug in, but to consider it to be a like a swiss army knife. Consider what you can do with it...
- Make surfaces ignore some lights in a scene
- Reduce or increase the effect of lights
- Allow photorealistic lighting effects
- Create variable light falloff
- Give a surface complex, multilayered specular highlights.
- Effect the look of Lightwave's renderer by changing the terminator
- Create custom ambient settings
And much more....
You'll seldom be doing all or even most of these things at one time on any one surface, which means that a lot of the time you will only be using part of the interface. Don't let this worry you - it's the normal way you use the plug in. Once you discover how powerful Lighter2 is, you might find you're using it in different ways every time you surface.
Light Sets allow you to apply different Lighter2 settings to different lights in your scene - remember that these changes to lights will only effect the surface you have selected.
How do you pick which lights are effected by any Light Set? By using the Include and Exclude functions, and the name of the light in the scene. Let's take a look at an example.
In the next picture, there are three sphere, all with different surface names. There are two lights in the scene. One is a white Distant light that has been given the name White Light. The other one is a red spotlight pointing straight down that has been named Red Light. These names (Red Light and White Light) are crucial - if you aren't in the habit of giving your lights nice descriptive names, you'll need to change your evil ways to work with Lighter2 properly.
The sphere on the left hasn't been effected by Lighter2 at all. The middle sphere had the red light excluded, and the sphere on the right had the white light excluded. How do you exclude lights? By bringing up Lighter2's interface, clicking next to the Exclude button and typing in a word that is in the name of the light or lights you want to exclude. In this example, all we had to do was type the word Red in the Exclude field - and be warned...this IS case sensitive, so if you type in red when the light is named Red, it won't work. Typing Red in the exclude field means that you'll exclude every light with the word Red in it; Red Light or Big Red or Redd Foxx or Talking Horse Named MRed - anything with that combination of letters somewhere in it.
Let's stop for a moment to remind you of something I said in the introduction - many times, you'll only be using part of the Lighter2 interface. In this example, we did something very poweful. We told surfaces to ignore certain lights. To accomplish that effect, we only used a tiny portion of the interface, namely the Exclude feature. That's all we needed to do for this surface, so we essentially ignored every other button. We only had to use one part of this 'swiss army knife' to achieve a highly useful effect.
Let's talk about some other features of Lighter2, and then we'll come back to talk more about Include and Exclude later. One important note - if you don't select specific lights by Including or Excluding them, changes to you make to Lighter2 setting will effect all lights in a scene.
Scale effects how lights effects a surface. Think of it as a way to crank up or turn down the lights on a surface by surface basis.
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The first example shows the effect of scaling, and it also show why the Clamp Intensity button is a Good Thing - it takes any light values over 100% and reduces them to 100%. Sometimes you want the overcranked look, though, so it's an option.
Let's combine a couple of tools on our Swiss Army Knife and look at the effects of combining a scale effect with the Include/Exclude feature. In our Exclude example above, we had the Default light set selected. In the Default set, you can exclude lights but you can't include them, so we need to pick another light set. Any set will do, but we'll pick Light Set 1.
We Include lights the same way we exclude them - by entering a text string, which Lighter2 then looks for in the names of your scene's lights. When you have the include function on, the panel's other settings ONLY effect the included lights.This means that if we have a Light Set that includes lights with the name Red and we pick a 50% scale value....then only the lights whose names contain the string Red will be scaled by 50%.
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This is a very cool and good thing - it allows you to selectively reduce or increase the effects of certain lights on a surface by surface basis. Neat, huh? As we go through Lighter2's other settings, remember that you combine Inclusion/Exclusion with almost any of Lighter2's effects. Also, with 11 different light sets, you can create a complex lighting/surfacing set up.
Let's look at some other settings. Contrast and Phase both effect the terminator. (No obvious Arnold jokes, please.) The terminator is basically the dividing point on an object that seperates light and dark. LightWave has a 'Sharp Terminator' button that makes the terminator very crisp and..umm...sharp. It's used for creating more realistic planets for space scenes.
Contast is a variable, envelopable version of the sharp terminator effect. You can use it to fine tune your terminator settings.
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Phase moves the position of the terminator. The number you enter is degrees. A setting of 180 would put the terminator on the opposite side of the object.
Transmittence gives you a 'creeping light' effect, such as you see on leaves. It's a useful addition to your lighting toolkit, and has applications such as adding a little bit of an edge to animated characters to help create a 'Pixar look'.
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Lighter2 also gives you a number of options for light falloff. You can apply different falloff settings to objects on a surface by surface basis. You can also decide between liner falloff (which is like LightWave's default falloff) or the more realistic exponential falloff. The Near and Far settings allow you to 'delay' the effect of falloff. For example, a near setting of 10 means that falloff won't start for 10 LW 'units' (between you and me, we all know that units means 'meters', so let's not be so politically correct...)
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One of Lighter2's most generally useful features is the ability to apply multiple specular highlight layers to a surface, each with it's own glossiness and highlight colors. This gives you much more realistic and complex specularity, without any significant increase in render times.
In our example, we added three layers of specularity to the surface of the Porsche's body. (The Porsche also had Fresnel2 color settings applied.) First was a very wide highlight (glossiness - 16) that was tinted purple, which gave the whole object a general gloss. Then a tight (glossiness - 256) bright (85%) layer was added. Specular layer 3 used the SI button, which takes the texture that you select in the LightWave Basic surfaces setting (in this case, fractal noise) and applies it using the glossiness and custom color settings you choose.
One important note - when you have the SI button turned on, the Specularity setting changes it's function. Instead of being a direct control of how bright the specularity should be, it becomes a 'level control', determining how much of the Texture comes through. So, 100% means that all of the texture will be visible. 50% would mean that only half of the texture's value would appear.
Specular layers are very powerful, and can add a lot of realism to your surface. Don't be surprised if you find yourself using it a lot.
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Settings for body surface |
Finally, you can use Lighter2 to set custom ambient settings on surface by surface basis. This would allow you, for instance, to have a moon with its own ambient setting. You can also apply a color to further customize the ambience.
