I wish radar icons were easier to discern from eachother.

From a distance, most of them look so similar to others that you'd need to squint in order to tell them apart. I mostly blame their lack of clear light-dark contrast, and would wish that they were mostly dark with color-coded highlights instead.

Still, even with such a change, the radar symbols look so abstract that, unless you learn about them, you wouldn't even be able to accurately guess what they'd mean from a glance. "Oh? An "X" marks an anti-swarm riot unit you say?" "What does that diamond symbol mean? Oh? An assault unit that wears down base defenses through attrition you say?" "That radar icon that looks like a person is a commander, right? Oh wait, it could also be a Detriment or an Ultimatum you say?"

With this in mind, what if the radar icons were made more clearly-defined, like, say, the various stat boosts that you'd collect in a game of Smash Run from Super Smash Bros 4?
[Spoiler]

Here are some examples of how various roles could be made more clear:
- Commander: Flag
- Constructors: Hammer
- Scouts (including Puppy and Owl): Eye
- Most raiders: Boot/foot with speed streaks
- Normal skirmishers: Bow and arrow
- AoE Riots (such as Outlaws, Rippers, Claymores, Venoms, Corsairs, and Scallops): Shotgun spread
- Rapid-fire Riots (such as Reavers, Felons, Archers, Recluses, Maces, Nimbus, and Dante): Front part of a gatling gun barrel
- Assaults (including Sirens and Detriments): Sword
- Precision artillery (such as Slings, Impalers, and Emissaries): Catapult with visible arcing trail
- Saturation artillery (such as Badgers, Firewalkers, Tremors, Merlins, and Shoguns): Hwacha firing off volleys of arrows, or MLRS/Katyusha rocket artillery firing off multiple missiles
- Anti-air: Upwards-pointing dual-barreled anti-aircraft gun
- Suicide unit: Cherry bomb or dynamite stick
- Anti-heavy skirmisher/artillery (such as Phantoms, Racketeers, Lances, and Paladins): Crosshairs
- Heavy gun-equipped siege unit (such as Grizzly, Crab, or Cyclops): A cartoonishly-short and fat cannon with treads/legs
- Transport: Hook and cable
- Drone: Top-down view of a quad-copter
- Drone carrier: Runway

Special cases:
- Scythe/Widow/Ultimatum: Bloody knife
- Iris: Curtain
- Dirtbag: Garbage bag
- Aspis: Shield
- Dominatrix: Heart
- Claymore (alternate symbol): Sea mine
- Djinn: Side-facing portals
- Placeholder: Vortex
- Jugglenaut: Minimalized, miniaturized Jugglenaut with raised leg, as if it's about to stomp on something
- Kodachi: Flame symbol
- Seawolf: Submarine (just as it is now)
- Swift: Boot/foot with speed streaks
- Raptor: Front part of a gatling gun barrel
- Raven: Crosshair
- Phoenix: A series of bombs
- Likho: A mushroom cloud
- Thunderbird: A storm cloud with lightning bolts poking out from underneath
- Gnat: Lightning bolt
- Zeus: Sword with lightning bolt overlay
- Blitz: Boot/foot with lightning bolt overlay
- Venom: Shotgun spread with lightning bolts replacing pellets
- Athena: Hammer overlaying a star
- Dante (alternate symbol): Head with devil horns
- Paladin (alternate symbol): Holy cross
- Detriment (alternate symbol): Skull
- Scorpion: Scorpion
- Scylla: Submarine with missile launching out of back

Finally, here are some ideas for images to apply as overlays for units of different factories:
- Cloakbots: Cape
- Shieldbots: Armored chestplate
- Jumpbots: Jets on the sides
- Amphbots: Air tanks on the sides
- Rovers: Wheels on the bottom
- Tanks: Tank treads on the bottom
- Hovercraft: Hover cushion on the bottom, and air-fans on the sides
- Spiders: Spider head and legs on bottom
- Ships: Sailboat
- Gunships: Helicopter blade on top, and helicopter pontoons on bottom
- Planes: Bird/plane when viewed from below
- Bipedal striders: Person
- Chickens: Zerg-like spike and mandible protrusions

As for the others, there is something to be said for simple and abstract icons. Even if their meaning isn't immediately obvious on first glance they yield less screen clutter in the long run.

Evolution RTS uses a set of icons similar to what you are describing. Assaults are represented with a hammer, riots with a fist, skirmishers are three bullets, etc. This results in thin, non-solid shapes, and doesn't really make units easier to recognize. I much prefer ZK's minimalist simple shapes.

You are free to make an icon set, or convince someone else to. I am fairly sure that you can use custom icons by adding some files locally to your install. We also have the ability to make alternate icons sets that can be selected ingame.

Here are some principals of the Zero-K icons that your suggestions tend to violate:

• Icons should be fairly solid and blobby. This is to give a better idea of the position of the unit and where to click to select it. It also makes crowds look neater.
• Everything (except constructors) should have a unique icon. When you make all the raiders boots with speed likes I don't see how you distinguish the 15 different raiders.
• Icons should be about the same size as their unit. Some of your suggestions seem too detailed to satisfy this.

Perhaps these principals are too limiting. Again, try out your scheme and test it out.

Since the Supcom icons were linked, I'll say that I think they are terrible because they have too many identical silhouettes. The roles of the units of a particular move type are distinguished by a few black or coloured pixels right in the center of the box.

Well, I just started work on some conceptual sprites that are mostly black with white highlights that would be recolorable depending on player color. Note that the black won't be transparent, as I'd like some good contrast between light and dark. Moreover, the reason why the sprites are mostly black instead of white is because I believe it's easier to spot light colors on dark backgrounds than the other way around. (Imagine trying to spot a fly in front of a floodlight, as compared to spotting a star in the night sky.)

So far, I'm covering most of the general unit roles.
[Spoiler]
The idea behind these 32x32 designs is that they would be inserted into bigger 48x48 or 64x64 designs, so that the unit's role is emphasized in the center, while the unit's type comes 2nd, as it's displayed on the border regions surrounding the role. So basically, it's kinda what we already do now.

And here are the 64x64 icons for the various unit types, in which the icon for the unit's role will replace the big white square in the middle.
[Spoiler]
By the way, GoogleFrog, how do I add my own custom radar icons in-game?

Oh gosh I remember when Mex and Storage had the same icon. And Pylon and Windgens. Good thing I changed them! \o/

For what it's worth, I always considered Zero-K to have relatively good and useful radar icons. Definitely far better than SupCom's (I couldn't tell any unit icons apart in supcom without looking really close and even then it was hard). They're also neater than S44's - for some reason I really didn't like those.

But I do remember that there was room for improvement. Some icons are still shared (how about comm icons, are they still all the same?) and some details are lost (jumpjet symbols were a bit small or lacked contrast iirc). I agree that sometimes the light-dark contrast wasn't perfect, ShadowWolfTJC. A complete overhaul would be the wrong way to go though, imo. And if it were to happen, then please make sure that they don't look worse and more important that no information gets lost!

1a zoom out until you see them.
[Spoiler]

On that subject, is there a setting for having the icons permanently displayed (instead of disappearing when the camera is close enough) with the unit model itself still drawn when close?

Use this slider instead of following random outdated advice.

I wish to bump this, because I'm still interested in making the radar icons a bit easier for me to distinguish from one-another, even if, for now, I'd be satisfied with inverting the brightness values (so that they're mostly light markings on mostly black backgrounds, which I'd be able to tell better than the mostly dark markings on mostly bright backgrounds). However, I STILL don't know how I can overwrite any of Zero-K's graphics files with some custom ones of my own.