Second Life Prim Lights – 1

In Second Life constructions few things are more misused and misunderstood than lights, full-bright, and glow. In this post, I’ll start looking at lights (!), and I will cover full-bright and glow in subsequent posts.

To begin with, let’s create a simple light. Start by rezzing a sphere, which will act as the light source. On the third tab of the Build dialog (Features) you will see the light options in the lower half. Tick the ‘Light’ checkbox, and the sphere will start to cast light (you might want to set your environment to midnight to see this to best effect).

You’ll notice that the sphere doesn’t light up in any way — it still looks like a plain plywood sphere. I’ll talk more about this in the next post, but in the meantime you can make it more realistic by going to the texture tab, setting the texture to blank, turning on Full-bright, and setting the Glow value to something like 0.02. You could also set the transparency (try a value of 25.0).

There are four basic parameters for lights, as you can see on the build dialog. The first is the colour. Clicking the colour square will bring up the standard colour selector.

The Intensity value is simply how bright the light is, and can take values from 0 (where the light is effectively off) to 1.0, at which point the light is at its brightest.

Well…”brightest” is perhaps misleading. You’ll notice that even at maximum intensity the light isn’t really very bright. It’s possible to create an even brighter light by putting a second light source right next to the first one. The light from both will combine where they overlap, and become even brighter.

The only problem with this is that you are using up another of your very limited number of lights (more on that in the next post).

The Radius value is, predictably, the size of the area that the light will be cast over. This isn’t a precise value, because there is a certain ‘fuzziness’ at the edges. It can range from 0.0 to 20.0.

The Falloff value describes how quickly the light ‘fades’ as it approaches the radius limit. In theory, a Falloff of 0.0 will stay at full intensity right to the edge, whereas a Falloff of 2.0 (yes, it goes to 2.0, don’t ask me why!) will fade away very quickly.

In practice, the Falloff is a much more subtle effect, and combines with the Radius value (which also has a rather subtle impact). Experimenting with them is the only way to really understand what their final effect is.

And that’s your basic light. More next time…