Reverse Engineering Earth 2150, Part 3: Vehicle Data

After talking to the Earth 2150 community a bit more, I hit the proverbial jackpot. I was able to get hold of the source file the PAR file was compiled from. It has the names of all of the fields, and they match the order of those in the PAR file. That means I have a lot more information than I did last time.

So far, I’ve adequately worked out meanings for types 1, 2, 3, 4, 6, and 7. Types 5 and 8 are very complex and has a lot of subtypes that I haven’t started work on yet. Type 9 is some sort of listing, and type 10 seems to be miscellaneous parameters, again still pending some research.

As I suspected, the -1 following each string is meaningless. Best guess, it’s padding to prevent buffer overflows, but I will most likely never know what the designer’s intent was. I won’t be including it in tables, but I’ll maintain its effect on the array index offsets. That means the field number will increment by 2 after each string field.

So, to make use of this information, I’ve rewritten my Python script to make use of this new information and spit out the decoded data for those six types. Maybe don’t try running it yourself; it uses a hard coded file path and is not even remotely error-tolerant.

Nonetheless, here’s what I’ve got, at least as regards type 1.

Type 1: Vehicles

There are 5 classes of vehicle:

Class Code Fields Description
MOVEABLE 0x0101c000 49 Base class that covers anything that doesn’t fit any of the below
SUPPLYTRANSPORTER 0x0101c001 54 Flying ammo transports
BUILDROBOT 0x0101c002 81 Gruz and Mammoth builders
MININGROBOT 0x0101c004 60 UCS harvesters
SAPPERROBOT 0x0101c008 59 Mine layers

The names are new, but I’d already worked the numbers out, more or less, without the source file.

Common fields

All Vehicle classes have the following basic fields:

# Field Type Description
0 classID int Explained above
1 mesh string Reference to a type 5 model entity
3 shadowType int Reference to one of several predefined shadow shapes
4 viewParamsIndex int Still don’t know what this is
5 cost int Money cost to build
6 timeOfBuild int Time to build in 1/20s ticks
7 $soundPackID string Reference to a type 8 sound pack containing unit sound effects
9 $smokeID string Reference to a type 5 smoke effect to emit when damaged
11 $killExplosionID string Reference to a type 5 explosion effect to use when destroyed
13 $destructedID string Reference to a type 5 wreckage entity
15 hp int Unit hit points
16 regenerationHP int HP regenerated per tick
17 armour int % kinetic damage reduction
18 calorificCapacity int How much heat can be absorbed from laser weapons before exploding
19 disableResist int Electrical HP; damaged by ion and lightning guns, disabled when 0
20 storeableFlags int Special effects that the unit can have applied, such as cloaking
21 standType int Not completely sure what this is, I think it refers to how closely the unit sticks to the center of the tile it’s in
22 sightRange int How many tiles the unit pushes back the fog of war
23 $talkPackID string Reference to a type 8 sound pack containing unit voice responses
25 $shieldGeneratorID string Reference to a type 7 shield generator class
27 maxShieldUpdate int Maximum shield generator level, -1 for no shield generator
28 slot1Type bitmask Equipment categories that can fit in slot 1
29 slot2Type bitmask Same for slot 2
30 slot3Type bitmask Same for slot 3
31 slot4Type bitmask Same for slot 4
32 soilSpeed int How many ticks it takes the unit to move into a tile with normal terrain
33 roadSpeed int Same but for road tiles, usually faster
34 sandSpeed int Same but for sand, usually slower
35 bankSpeed int Same but for slopes
36 waterSpeed int How many ticks it takes the unit to move into coastal water tiles
37 deepWaterSpeed int Same but for deep water
38 airSpeed int Still not sure about this one. I think it’s vertical speed for aircraft
39 objectType int Reference to a movement category. There’s one for tracks and wheels, one for helicopters, one for ships, and so on
40 $engineSmokeID string Reference to a type 5 smoke effect emitted when moving
42 $dustID string Reference to a type 5 dust effect emitted when moving
44 $billowID string Reference to a type 5 wake effect emitted when moving
46 $standBillowID string Reference to a type 5 ripple effect emitted when not moving
48 $trackID string Reference to a type 5 track effect left on the ground when moving

A few of these deserve special note. Field 3 is particularly interesting, as I would probably never have worked out that it was shadow shape just by reading the output. I’m pretty sure these are hard-coded effects inside the engine itself rather than anything defined in the parameters file.

I was utterly wrong about 4. I’m not sure what it actually does, but it’s definitely not factory building assignment.

And finally, 39 is the “movement type” field I was trying to cram into 3 before.

Looking at it, it’s kind of surprising how many of these I got right.

Supply Transporters

# Field Type Description
50 ammoCapacity int How many rounds the transport can carry per trip
51 animSupplyDownStart int Animation timing information
52 animSupplyDownEnd int Animation timing information
53 animSupplyUpStart int Animation timing information
54 animSupplyUpEnd int Animation timing information

Not really all that much extra here. These would have been hard to work out, as they’re all the same across units, and the animation timing stuff would have made no sense at all to me.

Builders

# Field Type Description
50 $wallD string Reference to a type 4 building that describes which wall type the unit makes
52 $bridgeID string Same but for bridges
54 tunnelNumber int Not completely sure, but I think it refers to the wall texture tunnels get when dug
55 roadBuildTime int How many ticks it takes to lay down a road
56 flatBuildTime int How many ticks it takes to flatten terrain
57 trenchBuildTime int How many ticks it takes to dig a trench
58 tunnelBuildTime int How many ticks it takes to dig a tunnel
59 buildObjectAnimationAngle int Which direction the unit should face relative to a site to start building there
60 digNormalAnimationAngle int Same for the tunnel digging animation
61 digLowAnimationAngle int Same for the trench digging animation
62 animBuildObjectStartStart int Animation timing information
63 animBuildObjectStartEnd int Animation timing information
64 animBuildObjectWorkStart int Animation timing information
65 animBuildObjectWorkEnd int Animation timing information
66 animBuildObjectEndStart int Animation timing information
67 animBuildObjectEndEnd int Animation timing information
68 animDigNormalStartStart int Animation timing information
69 animDigNormalStartEnd int Animation timing information
70 animDigNormalWorkStart int Animation timing information
71 animDigNormalWorkEnd int Animation timing information
72 animDigNormalEndStart int Animation timing information
73 animDigNormalEndEnd int Animation timing information
74 animDigLowStartStart int Animation timing information
75 animDigLowStartEnd int Animation timing information
76 animDigLowWorkStart int Animation timing information
77 animDigLowWorkEnd int Animation timing information
78 animDigLowEndStart int Animation timing information
79 animDigLowEndEnd int Animation timing information
80 $digSmokeID string Reference to a type 5 smoke entity that is emitted when digging

The type references were clear enough, but again, I’d never have worked out the animation details.

Harvesters

# Field Type Description
50 containersCnt int How many containers worth of resources the harvester can carry
51 ticksPerContainer int How many ticks it takes to mine one container
52 putResourceAngle int Direction to face when dropping off at the refinery
53 animHarvestStartStart int Animation timing information
54 animHarvestStartEnd int Animation timing information
55 animHarvestWorkStart int Animation timing information
56 animHarvestWorkEnd int Animation timing information
57 animHarvestEndStart int Animation timing information
58 animHarvestEndEnd int Animation timing information
59 $harvestSmokeID string Reference to a type 5 smoke entity emitted when mining

Minelayers

# Field Type Description
50 minesLookRange int Not entirely sure, but I think this is how far the minelayer will move to automatically sweep mines
51 $mineID string Reference to a type 5 mine entity that’s laid on the ground
53 maxMinesCount int Number of mines carried per reload
54 animDownStart int Animation timing information
55 animDownEnd int Animation timing information
56 animUpStart int Animation timing information
57 animUpEnd int Animation timing information
58 $putMineSmokeID string Reference to a type 5 smoke entity emitted when laying mines

Wrapping up

And that’s it. With the exception of fields 4 and 38, that’s every part of type 1 explained. More importantly, I think I have enough information now to run the process in reverse, which means I can compile a new PAR file with modified units in it. Next step will be writing that compiler, I think! But I’m not quite done yet. There are several more entity types to get through, and I’ll probably write those up tomorrow.

Posts in this series:

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