here is a little, neat trick for DEdit (and for sure, for other 3D-render programs and -editors as well) how to create an 'outlining'-effect. This is an effect known from drawn things, especially comics, and it is describing the optic when things are drawn with a more intensive style at their outer edges. That way, they can be shown more separated from the background and other elements in the drawn scene.
Now the big question : why talking about it here?
Well, during the last 4-5 years, working with DEdit and other 3D-rendering stuff, i collected/created a set of techniques and/or tricks that helped me creating maps in a more efficient way. Also, Tron itself is orientated to a style of computergraphics from the early 80's, at that time 3D-CGI always looked very 'edgy', so this optic can fit well (if used correctly and wisely).
IMPORTANT : It should be told at this point, that this effect can (but don't have to) be a massive backshot, if you don't use it right or to massivly in your maps. That said, your performance of the map could drop. So better make yourself some good thoughts about your map before you use this effect! And work cleanly, otherwise you create too much extra polygons, that will reduce the performance!
IMPORTANT : In each step of this tutorial i added the corresponding keys you sometimes could use. These are mapped to my keyboardlayout (german) and might be different if you changed the settings in your DEdit (heck, even i don't know which of my settings are still default or not :)).
Lets assume we're talking about an object like this in the map, where we want to have that outlining:
And our target is to reach such an effect:
How to do that?
It is simple. First duplicate the original(A) so you get a copy(B), that copy will be used for the outlining.
[SHIFT & C > SHIFT & V]
Now set the position of the copy(b) to the same as of the original(A)
[SELECT (A) > SHIFT & X > SELECT (B) > SHIFT & Z(maybe Y if your keyboard has not a german layout)]
In the next step, you increase the dimension of the copy(B) about 1 or 2 DEdit-units in each of the six directions. So like this:
(TIP: the higher the increase the more intense the outlining will be shown!)
Now put a texture onto the copy(B), for a Tron-styled map surely something 'glowish' :) (for toon-style you should use something black):
Flip the faces of all sides of the copy(b), so the outside is now inside (i have hidden the original(A) so you can see it better!):
All steps are done, all you have to do now is to compile/process your map, and make a test. You can run around in your map as much as you want, you will realize that only the outer edges of the cube will be showing.
Combined with, for example a flat-shading, you can also create a toon-look. You just need to setup a texture like something black on the copy.
Here are two example how this would look like if you have a more complex shape/architecture in your map, using this effect.