No, it's not what you think.
I posted a lament about this on the skinning forum, but I'd like to make an official wish of this:
Aces High still uses a single Diffuse map for the skin of each aircraft, which is virtually the extent of the detail available that's not already provided by the actual 3D mesh. There IS also the material.txt file which provides a degree of control over specularity, but IIRC, this applies shininess uniformly across the entire skin, and doesn't allow varying spec for different parts of the aircraft. Additionally, all detailing such as panel lines is implied through the use of shadow and highlight. Unfortunately there's limits to just how useful this is, particularly in closeups (my skins always look better from external view than from the cockpit).
It's definitely easy to implement and isn't very resource-hungry, but is a VERY old approach to implementing skins.
I'd like to see skins expanded to add two additional textures for each skin: A Specular Map and Normal Map.
Although I'm sure the experienced skinners already know what I'm talking about, for those of you not familiar with either concept:
Spec Maps are a Grayscale image (some games use RGBA: RGB determines the color of the reflected light, while the Alpha channel determines the intensity) that determine reflectivity of a surface. The brighter it is on the Spec Map, the shinier it is. Unlike the all-or-nothing material.txt, it would allow different surfaces to be given varying levels of shininess. Bare, polished aluminum could be given a very high reflectivity, with matte finishes for surfaces such as anti-glare panels and exhaust staining.
A Normal Map is an RGB image file. Normal maps will give skins a much better sense of depth. Features such as panel lines would stand out more without needing to use shading on the skin to provide the illusion of depth. Raised surfaces and sunken details would look far more realistic, particularly when viewed at very close distances such as from the cockpit interior. In other words, Normal Mapping makes a 2D surface LOOK like it's 3D. It even reacts to light and shadow as if it were three-dimensional.
VERY quick example of a Normal Map I whipped up from my Corsair template:
You can ESPECIALLY see the effect if you look at the riveted areas between panel lines on the leading edge of the wing and horizontal stabilizer.
To give you an example of just what you can do with Spec and Normal mapping, this is a sword I made for Dragon Age: Origins. The image on the left uses a Normal Map while the one on the right does not. I wish I could have gotten them under the same lighting, but you can still REALLY tell the difference by how much more the normal-mapped details stand out.
It uses a slightly different type of Normal Map than what I posted above (this one is made up of two grayscale images: one that fills the RGB channel, with the second assigned to the Alpha layer) but the effect is the same. For reference, almost ALL the details on this sword: the knotwork, dragon design, and the engraved runes around the pommel, are done entirely using a Normal Map. Imagine this level of detailing on an aircraft in Aces High!
For players who have older systems HTC could allow the Spec and Normal maps to be disabled for performance, giving them just the Diffuse maps that the game already uses. Nothing would change for these players. It also wouldn't provide a tactical advantage for players with high-end systems (MAYBE if high-spec skins, IE BMF P-51s, etc., made the aircraft MUCH more visible under lighting, which would certainly be realistic) but would greatly enhance the visual appeal of the game.
This isn't brand-spankin' new technology, either. Normal and Spec mapping have been in use for a LONG time in gaming, and it would make a HUGE difference to see Aces High catch up and implement this.
