I think 2D radar could use a bit of a touch up on the tabling side and 3D radar needs to be burnt to the ground and remade.
2D radar:
Add the ability to scale radar icons based on resolution/HUD scale
have the radar icon of the currently selected item indicated in some way such as drawing it at full brightness
indicate attackers (flash icon)
Move radar icons to HUD table or its own table.
Add flag: $Radar 3d Image Size (sets size of radar icon on the 3D radar. If not present default to $Radar Image Size)
Radar section of the HUD table (or separate radar table) functions as follows:
Holds the radar icon parameters. Top level is ship type (as defined in ship flags) and has parameters for a generic radar icon for the ship and any associated sizing parameters. Individual Classes can be named as sub items. Missing items filled in from parent (ship type). Can also have subclass defined, but if not present will use class (Orion#Galatea will use Galatea entry if one exists, if not will use Orion entry). If an entry is not present will use the next highest entry (Orion#Galatea will use Galatea entry within orion if it exists, otherwise uses Orion entry, if that also does not exist, uses capital entry).
Possible: can be overridden by radar entry in ships.tbl
Separates icon from the ships table and provides a fallback option for ships without an icon defined (eg. when playing a mod). Also lets generic icons be quickly updated without duplicating the same parameters dozens of times providing easier maintenance and potential future expansion.
Sample table fragment:
$Ship Type: Capital
$Radar 2d Image: Capital
$Radar Image Size: 30
$Radar 3d Image Size: 24
$3D Radar Blip Multiplier: 1.0
$Ship Class: Orion
$Radar 2D Image: Orion
$Radar Image Size: 28
$Radar 3d Image Size: 24
$3D Radar Blip Multiplier: 1.0
$Ship subclass: Galatea
$Radar 2D Image: Galatea
$Ship Class: Hecate
$Radar Image Size: 30
$Radar 3d Image Size: 24
$3D Radar Blip Multiplier: 1.0
$Ship Type: Cruiser
$Radar 2D Image: Cruiser
$Radar Image Size: 16
$Radar 3D Image Size: 14
$3D Radar Blip Multiplier: .75
In this Orion#Galatea would use the Galatea radar icon (with the size parameters given in orion) while Orion#Bastion would use Orion Icon. A Typhon, lacking an entry would fall back to using the generic Capital ship icon. Top level in this table is ship type flag in ships.tbm, lower levels taken from $Name: in ships.tbm
3D radar. This needs redone in a bad way. It's old, it looks old and the rings never line up, plus it doesn't play nice with the radar icons.
Replace the whole thing. (would love if someone could do a mock up of this)
For the replacement my thought is, when the 3D radar is active, disable the 2D background. In it's place draw a Sphere, Semi-transparent (takes radar gauge color), possibly with longitude and latitude drawn at regular intervals (30 degrees maybe). Bottom half (points towards mission down) is drawn at a different brightness, so functions as artificial horizon, also has marker for mission north on the surface (everything except for just drawing a sphere is optional really).
In the center have a white dot representing the ship. Alternatively, draw the ship's radar icon.
The Sphere represents a distance of a few hundred meters from your ship. Accordingly draw blips or radar icons for each contact at a distance from the sphere based on the distance from the ship. contacts within a certain range may be drawn inside the sphere. Connect each contact to the surface of the sphere with a line to better show exact angle and distance. Another invisible sphere surrounds the visible one and marks the furthest out radar icons can be drawn regardless of actual distance If the radar distance is not set to infinite, max range ships will draw at the perimeter sphere.
Additional options: Cone or arrow outside the perimeter sphere that points towards any set waypoints.
Threat indicator yellow line(s) and blip(s) connected directly to the center ship icon (rather than just the radar sphere) that indicates the range and direction of incoming missile(s)
Possibly have the draw range of ship icons on a logarithmic scale; the upside is it's easier to differentiate distances of ships close enough to affect you, but the downside is it may be harder to tell closing speed or the distances of far ships.