Materials that respond to distance?

[Hypnagogia]

Hi there,

I'm trying to make something along the lines of an invisible barrier that becomes visible as the player moves closer to it. I've used this Hourences page as a reference, and set up my material as shown in the picture:


It does get the desired effect, but backwards from how I want it. The object is visible at a distance, and becomes more transparent as the player moves closer. How can I reverse this?

Also, does anyone know what those little yellow checkboxes on the material nodes do? I've toggled them on and off but haven't noticed any differences.

Thanks for your help!

[obihb]

You can use a "one minus" node to invert your effect.

The yellow box is to give real time feedback in that node. For example, if you had a panner node on a texture and you check the yellow box on the texture node, you can see the panning in real time.