This summary might be useful to people designing their own tech tree.
Here's a quick run down of tech tree tags (and ignoring a few struture issues), I see the following things being read (and looked for in the order given), with the following parameters:
BEGIN_TECH string<name> num<id>
CATEGORY num
DESCRIPTION string
TEASER string
IMPROVE_DESC string
REQUIRES num<requiredTechId>
COST num
EDEN_COST num
PLYMOUTH_COST num
MAX_SCIENTISTS num
LAB num
PLAYER_PROP propName num<propValue>
FUNCTION_RESULT propName
UNIT_PROP unitName propName num<propValue>
END_TECH
Some tags can be used multiple times for the same tech to specify multiple results. These include "REQUIRES, "PLAYER_PROP", "FUNCTION_RESULT", and "UNIT_PROP".
The tag "FUNCTION_RESULT" is quite useless. It seems to be a feature that was never completed. The only function you can specify is "Test_Function", which just returns. (A DLL could overwrite this tag or the default function address, but since the function doesn't return a value, and must therefor handle all required effects itself, this is no different then using a ResearchTrigger).
If the research cost is the same for both colonies, then you can just use "COST". It will set the internal fields for both the Eden and Plymouth research costs. If you want them to be different, then specify "EDEN_COST" and "PLYMOUTH_COST". Note that you can probably mix these tags around, but "COST" will overwrite the results of the other tags when it's processed.
The "propName" values are looked up in a list. Each propName has an intended purpose, but the game doesn't error check these (as far as I remember), so you can mix propNames and stick them where they don't belong for odd effects. Beware though, as it might cause the game to crash. This is mainly in reference to mixing vehicle unit prop tags with building unit prop tags. (Such as Turn_Rate, and Power_Required). You can check the UnitTypeInfo.txt file in the internal data structures download to try and predict the effect of a tag when it's used where it wasn't intended. (Note that Rate_of_Fire and Storage_Capacity have the same offsets, and so they will have the same effect if you use either on a given unit).
Possible values for "propName" (prefixed by the hex offset of their value) are:
// UNIT_PROP
0x0 Hit_Points
0x8 Armor
0x34 Production_Capacity
0x24 Move_Speed
0x18 Sight_Range
0x30 Rate_Of_Fire
0x14 Build_Time
0x24 Power_Required
0x30 Storage_Capacity
0x38 Storage_Bays
0x2C Production_Rate
0x28 Concussion_Damage
0x2C Penetration_Damage
0x1D Improved
0x28 Workers_Required
0xC Common_Required
0x10 Rare_Required
0x28 Turn_Rate
0x14 Build_Points
// PLAYER_PROP
0x20 Ore
// FUNCTION_RESULT
0x472910 Test_Function
For UNIT_PROPs, most tags simply overwrite an offset at a fixed location within the UnitTypeInfo class for that player with the value given. A slight exception seems to be with the "Armor" tag. For this tag (identified by the address within the propName table), it uses the value as an index into a table of armor values. It sets the corresponding looked up value when research completes. The armor table is as follows:
0x100 = 256
0xB4 = 180
0x82 = 130
0x5A = 90
0x3C = 60
0x28 = 40
Mixing propName tags between UNIT_PROP, PLAYER_PROP, and FUNCTION_RESULT tags may cause a random property on a random unit, or a random player property to be set to a random value. Probably not a good idea, nor does this seem to be of any use. (I haven't tested this, but if someone wants to, let me know how it goes).
The value written for each unitProp is 4 bytes. Note that "Improved" is not a 4 byte aligned offset. (It might overwrite part of a second field?)
The "unitName" field can take any of the internal unit names. (It loops through the UnitTypeInfo array and calls the second function in the virtual function table to get the name of that unit type. If you write code to add a new unit, it's properties can be set with this tag name). Since this table didn't paste too cleanly, the part in caps is the actual tag name, and the lower case part is the more commonly know in game name of that unit. A list of these tags is:
// Unit type 0
MAX_OBJECT_TYPE first unit on the list
// Vehicles
BIG_TRUCK cargo truck
CON_TRUCK convec
SPIDER spider
SCORPION scorpion
LIGHT_TANK lynx
MED_TANK panther
BIG_TANK tiger
SURVEYOR robo surveyor
MINER robo miner
GEO_METRO geo con
SCOUT scout
BULL_DOZER robo dozer
MOBILE_HOME evacuation transport
REPAIR_TRUCK repair vehicle
WALL_TRUCK earthworker
SCAT small capacity air transport
// Walls and tubes
TUBE tube
WALL wall
WALL_LAVA lava wall
WALL_MICROBE microbe wall
// Buildings
MINE common ore mine
MINE_ADV rare ore mine
TOWER_GUARD guard post
TOWER_LIGHT light tower
STORAGE_ORE common ore storage
STORAGE_RARE rare ore storage
FORUM forum
COMMAND command center
ASE mhd generator
RESIDENCE residence
ROBOT_COMMAND robot command center
TRADE trade center
LAB basic lab
MED_CENTER medical center
NURSERY nursery
SOLAR solar power array
RECREATION recreation facility
UNIVERSITY university
AGRIDOME agridome
DIRT dirt
GARAGE garage
MAGMA_WELL magma well
METEOR_DEF meteor defense
GEOTHERMAL geothermal power plant
FACT_ANDROID arachnid factory
FACT_LUXURY consumer goods factory
FACT_STRUCTURE structure factory
FACT_VEHICLE vehicle factory
LAB_STANDARD standard lab
LAB_ADV advanced lab
OBSERVATORY observatory
RESIDENCE_P reinforced residence
RESIDENCE_E advanced residence
SMELTER common ore smelter
SPACEPORT spaceport
SMELTER_ADV rare ore smelter
GORF gorf
TOKAMAK tokamak
// Weapons
ACID acid cloud
EMP emp
LASER laser
MICROWAVE microwave
RAIL_GUN rail gun
CANNON rpg
SELF_DESTRUCT starflare
SELF_DESTRUCT_ADV supernova
TURRET_DESTRUCT guard post starflare
TURRET_DESTRUCT_ADV guard post supernova
SCUTTLE_DESTRUCT normal unit explosion
SPAM esg
FOAM stickyfoam
THORS_HAMMER thor's hammer
SCORPION_WEAPON energy cannon
EMP_BIG emp missile blast
BFG ...
// Disasters
LIGHTNING storm
TORNADO vortex
EARTHQUAKE earthquake
ERUPTION eruption
METEOR meteor
// Resources
BEACON mining beacon
MAGMA_VENT magma vent
FUMAROLE fumarole
// Wreckage
WRECK_FLAG wreckage
// Building explosions
BLD_EXPL_SML disasterous building explosion
BLD_EXPL_MED catastrophic building explosion
BLD_EXPL_BIG atheist building explosion
// Space
EDWARD edward satellite
SOLAR_SAT solar satellite
SPACE_1 ion drive module
SPACE_2 fusion drive module
SPACE_3 command module
SPACE_4 fueling systems
SPACE_5 habitat ring
SPACE_6 sensor package
SPACE_7 skydock
SPACE_8 stasis systems
SPACE_9 orbital package
SPACE_10 phoenix module
SPACE_11 rare metals cargo
SPACE_12 common metals cargo
SPACE_13 food cargo
SPACE_14 evacuation module
SPACE_15 children module
SULV sulv
RLV rlv
EMP_MISSILE emp missile
// Consumer goods
LUX_1 impulse items
LUX_2 wares
LUX_3 luxury wares
// Inter colont shuttle
SHUTTLE inter colony shuttle
// Arachnid packs
SPIDER_PACK spider 3 pack
SCORPION_PACK scorpion 3 pack
// Animations
AMBIENT_ANIM pretty art
// Unit type 0x74
MAX_OBJECT_TYPE last unit on the list
Interesting how they only added the Ore value tag, so all you can do is research something to get your ore set to a known amount. Probably not too useful. Could maybe be used for some obscure custom level, but it's far from the normal way of playing. I guess that means only Unit_Prop is really useful then, and just ignore the Player_Prop and Function_Result tags.
I just took a quick peak at the "Improved" tag. Seems to be used by:
Common Ore Mines
Rare Ore Mines
GORF
Common Ore Smelter
Rare Ore Smelter
Observatory
The Player_Prop and Function_Result are never used in the original tech files.
Just stumbled across a tech tree overview file I had generated. Thought it might be useful to post it.
There does seem to be a bit of logical grouping (although inconsistent) with the hundreds place of the techID, but there's really nothing special about it. The game doesn't treat anything below the thousands place as special.
1 2099 PE Spider
2 2101 PE Agridome
3 2103 PE Command Center
4 2104 PE Structure Factory
5 2106 NOT AVAILABLE
6 2107 PE Light Tower
7 2108 PE Common Ore Mine
8 2109 PE Residence
9 2110 PE Common Ore Smelter
10 2111 PE Common Metals Storage Tanks
11 2112 PE Tokamak
12 2114 PE Tube
13 2115 PE Trade Center
14 3101 PE Standard Lab
15 3201 PE Seismology
16 3202 PE Vulcanology
17 3301 PE Emergency Response Systems
18 3302 PE Metals Reclamation
19 3303 PE Health Maintenance
20 3304 PE Offspring Enhancement
21 3305 PE Research Training Programs
22 3306 PE Leisure Studies
23 3401 PE Cybernetic Teleoperation
24 3402 PE High-Temperature Superconductivity
25 3403 PE Hydroponic Growing Media
26 3405 PE Metallogeny
27 3406 PE Environmental Psychology
28 3407 PE Large-Scale Optical Resonators
29 3408 PE Focused Microwave Projection
30 3501 PE 03501 Robot Command Center
31 3502 PE 03502 Vehicle Factory
32 3601 PE 03601 Scout
33 3602 E Laser Turret
34 3603 P Microwave Turret
35 3604 PE Cargo Truck
36 3605 PE Construction Vehicle
37 3606 PE Earthworks Constructor
38 3607 NOT AVAILABLE
39 3608 PE Robo-Dozer
40 3609 PE Robo-Miner
41 3610 PE Robo-Surveyor
42 3801 PE Guard Post
43 3851 PE Mobile Weapons Platform
44 3901 PE Advanced Vehicle Power Plant
45 5051 PE Robot-Assist Mechanic [Eden, (free for Plymouth)] (Garage, Repair Vehicle)
46 5052 PE Robot-Assist Mechanic [Plymouth, (free for Eden)] (Garage)
47 5101 E Consumerism
48 5102 PE Garage
49 5104 PE Lab, Advanced
50 5106 PE Walls, Concrete
51 5107 P Magnetohydrodynamics
52 5108 P Public Performance
53 5110 PE Rare Ore Processing
54 5111 PE Independent Turret Power Systems
55 5115 E Geothermal Power
56 5116 P Legged Robots
57 5201 PE Advanced Combat Chassis
58 5202 P Dissipating Adhesives
59 5302 PE Meteorology
60 5303 PE Severe Atmospheric Disturbances
61 5305 PE DIRT Procedural Review
62 5306 PE Recycler Postprocessing
63 5307 PE Automated Diagnostic Examinations
64 5309 E Hypnopaedia
65 5310 P Hypnopaedia
66 5317 PE Reinforced Vehicle Construction
67 5318 PE Robotic Image Processing
68 5401 E Repair vehicle
69 5405 PE Space Program
70 5408 P Forum Reconfiguration
71 5501 PE Smelter, Rare Ore construction
72 5502 PE Storage Tanks, Rare Metals
73 5503 PE SULV
74 5504 PE EDWARD satellite
75 5506 E Directional Magnetic Fields
76 5508 PE Electromagnetic Pulsing
77 5599 PE Rocket Propulsion
78 5601 P Heat Dissipation Systems
79 5602 P Rocket Launcher
80 5701 PE Lava Defenses
81 7102 PE Explosive Charges
82 7103 P Multiple Mine Projectile System
83 7104 P Arachnid Weaponry
84 7201 PE Rare Ore Extraction
85 7202 PE Hot-Cracking Column Efficiency
86 7203 PE Smelter Postprocessing
87 7206 PE Scout-class Drive Train Refit
88 7211 E Extended-Range Projectile Launcher
89 7212 P Extended-Range Projectile Launcher
90 7213 E Advanced Robotic Manipulator Arm
91 7214 P Advanced Robotic Manipulator Arm
92 7403 E Increased Capacitance Circuitry
93 7405 P Scorpion Power Systems
94 8049 PE Meteor-Watch Observatory
95 8051 E Observatory
96 8103 E Magma Refining
97 8104 E Expanded Housing
98 8105 P Disaster-Resistant Housing
99 8106 E High-Energy Ray-Composite Projector
100 8201 PE Dual-Turret Weapons Systems
101 8203 P High-Powered Explosives
102 8301 E Efficiency Engineering
103 8302 P Efficiency Engineering
104 8304 E Heat Mining
105 8306 PE Enhanced Defensive Fortifications
106 8307 PE Multitainment Console Upgrade
107 8309 PE Reinforced Panther Construction
108 8316 PE Meteor Detection
109 8317 PE Meteor detection
110 8319 P Spider Maintenance Software Revision
111 8320 P Reduced Foam Evaporation
112 8321 P Arachnid Durability
113 8401 NOT AVAILABLE
114 8503 E Acid Weaponry
115 8601 PE Skydock
116 8801 PE Ion Drive Module
117 8901 PE Fusion Drive Module
118 8951 PE Fueling Systems
119 10101 E Improved Launch Vehicle
120 10102 E Artificial Lightning
121 10202 PE Command Module
122 10204 PE Solar Power
123 10205 PE Habitat Ring
124 10206 PE Sensor Package
125 10208 PE Stasis Systems
126 10209 PE Orbital Package
127 10301 E Magma Purity Control
128 10303 PE Advanced Armoring Systems
129 10305 E Grenade Loading Mechanism
130 10306 P Grenade Loading Mechanism
131 10309 E Precision Trajectory Projection Software
132 10401 PE Phoenix Module
133 11999 PE Tiger Speed Modification
134 12101 E Heat Dissipation Systems
135 12201 P Rocket Atmospheric Re-entry System
136 12499 NOT AVAILABLE
137 12599 PE Evacuation Module
Note: Above table attached as a txt file.