I figured I'd post this over here, rather than in the coding forum, since it's really more of an art question.
I'm planning on introducing the ability to have real-time glow/bloom effects in the battlescape, similar to what I've done for the geoscape (see screenshot). The coding I can handle, but before that code is useful, it will require some decisions about how to use it with the artwork.
There are essentially two different ways that we can do glow. The first is to do HDR (high-dynamic-range) rendering, in which case things will "glow" when they're brighter than the maximum brightness that can actually be displayed by your monitor (ie. if the value for the red channel is greater than 255, the "extra" red will spill over into neighboring pixels on the display). This is how things work in the newer Halflife2 games, for example (though they do some other more complicated things as well, like adjusting the centering of the visible-dynamic-range on the fly). New art wouldn't be required immediately, but this would wind up changing the appearance of things that were already in the game. Given that the current textures weren't designed for HDR, this could create some issues that would require fixing textures and/or lighting to get things looking right again.
The other option is to do glow in a style that has come to be known as "Tron" style glow, since it was pioneered by the game Tron 2.0. The idea here is that you can associate an optional extra texture with a model, much like you would a normal-map, which specifies what regions of the model should glow (along with color and intensity). This wouldn't change the look of the game initially, but would require new art to define what should be changed and what should be left the same.
My personal preference is for the second option, at least initially (I may implement them both eventually), because it allows a much greater degree of artistic control, and I think it will fit well with the atmosphere of the game. Having the "bright green" portions of UFOs glow, for example, seems like a natural extension of the current artistic style. It would probably even be possible to have simple animations in which the glow-texture was varied over time, allowing things like pulsing or other fun visual effects.
The caveat, however, is that this would require new art. Any model that didn't have an associated "glow" texture simply wouldn't glow. This would mean that glow textures could be added slowly; the game wouldn't break because they weren't there, but new textures would have to be created before the new effects actually appeared in game.
Thoughts?
