Fall-Off Simulation, in Blender
Author: Pablo Vazquez - Translation: Emmanuel Reyna - Software: Blender 2.34+

Are you looking for the Area lights tutorial? Click Here!
...but this method takes a long time to render, and it's annoying to configurate, so.. why not simulate fall-off whit ramps, if it is so easy and quick?

· Hi Ramps! bye Area lights! =) This time we'll use another .blend as an example, take it from here, or make one by your own (recommended!). It's an usual shape, just subdivided and extruded the default cube.

1. Object.

2. Ramps Panel.

· Where are Ramps? Ramps are, since 2.34 Blender's Version, in shading (F5) of material, in his own panel. In this case, we'll use just the ramps that modify the color (Show Col Ramp button), if you want more information about this ones check out: http://www.blender3d.org/cms/Ramp_Shaders.348.0.html I recommend you to read it if you don't now anything about ramps, as I won't explain what they are or how to use it, I'll explain just how to get the effect.

· Fall-Off Fall-off consists in the lightening or aplication of a color (generally lighter than the base one) acting in the mesh's edges, (from the camera view), giving a smooth aspect to it, without taking into account the scene ilumination.

3. Colorband and Ramps settings.

4. Settings of the image at the bottom.

· Let's ramp! Ramps allow us to choose a color band for the same material, but in this case we'll use only 2, the base one and a light one. We'll put the main colour in the right, and, the same colour but lighter or directly white, we'll put it in the left, one in each side. With interpolation type "Ease" (the first little square next to "Del" button). In method we'll use "Mix", and in "Input", we'll select "Normal", this is what gives the effect, the light colour distributes itself following the normal's coordinates of the object relationed to the camera, *illuminating* the edge of this mesh and giving that smooth effect, Fall-off.

Note: If we have the ramps occupied giving another effect, we can achieve the fall-off with a texture of Blend type [Sphere], affecting the color and/or emit, asigned to the Nor channel and fitting coordinates to -,-,z.
But if we're not using Ramps, it's a good way of using them.

The rest of the material's options they are to own election, in the image I've got Spec at 0, Ref at 1, Translucency in 0.20 and Emit in 0.1. But it isn't necessary to get the effect.

5. Example of Fall-Off with ramps.

Alternatives:

6. Example of Fall-Off with nodes.

If you want to give nodes a try, (still not in Blender 2.41). Here is an screenshot of the node editor, there you can see the settings for the image above, I assume that you already know how to use nodes.

I hope this results useful for you.
Pablo Vázquez (venomgfx)
Translation: Emmanuel Reyna
info [at] venomgfx.com.ar
www.venomgfx.com.ar

feel free to translate this tutorial in your language! just let me know =). You can use any source of this tutorial, mentioning my site.