The simplest effects are often the most effective. Since the release of Natural Selection, I?ve been bombarded by questions as to how the electrical arc effect in the Keyhole and Triad areas was accomplished. A few people have managed to use their own wits to correctly figure out the method behind the effect, but a majority overlooks the simple entity that makes it all possible.

Func_conveyor.

At this point in the tutorial, a third of you smack yourselves in the forehead and immediately implement the feature flawlessly in your own level. Another third stares blankly at the screen, saying, ?No, it can?t be THAT simple, what?s the catch?? The final third then still hasn?t figured out how to get the desired effect. It?s for that last third that this tutorial continues without degrading into a feature of dancing chimpanzees.

At this point, I should take a second to give some credit to Jon "Merkaba" Chapman, the man behind ns_hera and the man responsible for showing me this specific use of the effect and creating the texture used in the process. Without him, I?d still have had a funky func_conveyor effect, but nothing near what it is now.



I?ll assume for the purposes of this tutorial that you already have created the architecture on which the electrical arc will be placed. I?ll use the Keyhole area from ns_eclipse for demonstration purposes. Once I had the base architecture in place, I added the brushes that would form the first layer of func_conveyors, textured with SCROLLARC.


(This texture can be found in ns.wad)

The brushes for the func_conveyor lay 1 unit out from the base architecture (in this case, a wall textured with CORETEXTURE). Once tied to the func_conveyor keep in mind that scroll textures always scroll from left to right when applied to func_conveyor brushes. To adjust the scrolling angle, you?ll need to rotate the texture on the face itself.



In the case of the Keyhole, I was aiming for a vertical effect. Rather than simply rotating the texture to 90 degrees, though, I instead used a value of 95 degrees. This combined with slight X and Y offsets and texture scaling will give you the most random appearing effect. Texture scale is particularly important ? Try to make sure the texture fits or is a near fit for the surface it will be covering. Standard or small texture scales can result in a very blatant (and ugly) repetitive tile effect. In the case of the Keyhole, I used a scale of 4 times the original texture. The offsets and angles varied from one conveyor to the next.

Now open up the conveyor properties. First, we?ll need to make sure the arc displays correctly. Set the Render Mode to ?Additive? and enter ?255? for FX Amount (If you are using an env_gamma in an NS map, you will need to, in most cases, use a lower FX Amount number due to overbrightening in-game. I find that an FX Amount of 175 is fairly appealing at an env_gamma setting of 1.7, the setting used in Eclipse.)

Once the render mode is set, move to conveyor speed. If you have an array of electrical arcs, you?ll want to be sure to randomize your speed values a bit, much like with the angles and offsets in texture alignment. Speeds from 192 to 256 will generally give the best results. Also be sure to check the ?Not Solid? and ?No Push? flags ? I in fact slightly overlooked the ?no push? flag myself on part of the Keyhole, which led to a few people?s discovery of the method behind this effect!



Finally, take the func_conveyor(s) you have just created, copy/paste them, and flip them appropriately that the texture is now scrolling in the opposite direction. Go through and repeat the texture and speed randomization process on the cloned func_conveyors. The second set should occupy the exact space as the first. This will, with proper speeds, angles, and offsets, give the final appearance of a seemingly (at least somewhat) random pattern of electrical arcs coursing along your wall, floor, ceiling, generator, or whatever else.