View source for Talk:OBDATA.DAT

Would anyone know how to change the TUs needed to work the psi-amp? I don't see anything in OBDATA (all its TU fields are set to 0). It would be helpful to [[MTR_Psi_Testing|psi testing]]. NKF?  ---[[User:MikeTheRed|MikeTheRed]] 16:29, 7 September 2006 (PDT)

:In case someone is still interested, I located these pieces of code that may be related to psi attacks (note that 25 = 0x19) :
 .text:0041F163 8B 15 88 3E 4A 00       mov     edx, currentUnit_pUnitRef
 .text:0041F169 80 7A 0C '''19'''             cmp     byte ptr [edx+0Ch], 25          ; current TUs
 .text:0041F16D 0F 82 94 01 00 00       jb      loc_41F307
:and
 .text:0041F230 A1 88 3E 4A 00          mov     eax, currentUnit_pUnitRef
 .text:0041F235 80 40 0C '''E7'''             add     byte ptr [eax+0Ch], -25         ; consume TUs
:(-25 = 0xE7).
:You may want to change the values I hilighted and see what happens when you try to panic a unit ;-)
:Same for mind control:
 .text:0041EE89 80 7A 0C 19             cmp     byte ptr [edx+0Ch], 19h
:and
 .text:0041EF55 80 40 0C E7             add     byte ptr [eax+0Ch], 0E7h
Have fun! [[User:Seb76|Seb76]] 14:39, 28 April 2008 (PDT)

IT WORKS. Seb76, you're a genius. TUs for MControl and MPanic, tested. Just one glitch, the pop-up menus show the old values. Could you please tell us what more should be changed? --[[User:Kyrub|Kyrub]] 16:44, 30 August 2008 (PDT)
----

Unfortunately obdata doesn't store all weapon stats. Unique actions like the costs for priming grenades, throwing stuff, mind probe, psi amp, etc are tucked away in tactical.exe. Hmm, I'm positive that they can be located, but there are so many iterations of similar values that it could take a long while to discover them. 

What could make thi worse is the possibility that these in-built actions (perhaps even the in-built alien melee attacks) will not be clustered together near each other. 

- [[User:NKF|NKF]]

----

Arg. Well it's not a real big deal. The psi equations are now known quite well; it'll be posted shortly. Reducing psi-amp TUs would make it easier to ultra-tune the psi equations, but it wouldn't make any difference to players. Don't knock yourself out, but if you can find it, that'd be nice! Thanks for the reply ---[[User:MikeTheRed|MikeTheRed]] 18:40, 8 September 2006 (PDT)

==Lazar Blastas!!1==
It occurs to me that I have no idea what it is that allows the laser weapons to fire without a clip. At first I thought simply giving them a base power rating (something other weapons don't have) was the key, but apparently giving a clip a power of 0 doesn't render it useless...

Can someone provide some details on this?

-[[User:Bomb Bloke|Bomb Bloke]] 03:32, 4 October 2007 (PDT)

-----

Just a quick gaze at obdata, it seems that the laser's three clip types appear to be set to 255 (or -1 if we think in terms of signed values) to mark that they're not used and the item has a power rating. Apart from that, I can't see anything terribly out of the ordinary. - [[User:NKF|NKF]]

-----

To make a weapon clip-less and ammo-less you must set the clip references all to 255 like NKF mentioned. Make sure to set a power rating in [022] (if you want the weapon to do damage that is, this field is not a requirement for a laser-type weapon) and don't forget to switch the damage type in [031] from 255 to a valid number. That combination should create a laser-type weapon without ammo or clips. Hope that's what you were looking for. --[[User:Zombie|Zombie]] 20:02, 4 October 2007 (PDT)

-----

That sounds about right. Thanks guys. :) 

- [[User:Bomb Bloke|Bomb Bloke]] 20:10, 4 October 2007 (PDT)

----

For clipless weapons, it might be enough just to set the ''first'' clip type to xff/255 - the game then doesn't look for the 2nd and 3rd clip type. I think. I did that by accident and I didn't check it terribly rigorously. [[User:Spike|Spike]] 19:39, 22 November 2008 (CST)

== Damage Type Hacking ==

A lot of the damage type behaviour seems to be hardcoded. For example here was some of my experience. (Maybe I made some mistakes, please check for yourselves.)

* If you hack a ranged weapon's damage type to Stun, it automatically becomes a Stun Explosion (area effect), like the Small Launcher Stun Bomb. (Tested 4 weapons) 
** (To implement a non-area ranged stun weapon, give it weapon power 5 so it will never affect outside its target square. Give it high ammo and low %TUs - fire continuously!)
* If you hack a non-IN weapon to IN, it doesn't create a fire effect. (Tested AutoCannon - but as a laser-style clipless weapons as per previous section)
* If you hack a Grenade to Stun, it still does normal damage (no Stun) and it still destroys objects on the ground

This is a shame because I wanted to implement a Flamethrower or Tank/Flamethrower - an Incendiary weapon with a weapon power of about 10 IN, but %TUs/shot of 1% and infinite ammo. Oh well! I guess I can still do it using AC-IN and giving it low %TUs, high ammo capacity. 

On the other hand, these things work as expected:

* Hacking a non-IN ammo type to IN seems to work. So I could hack AC-AP, AC-HE to IN. Both started IN-type fires. The hacked AC-HE did not damage objects. 
* I could hack AC-IN to AP and it did not retain any area affect (or fire effect).
* I could hack all HC- ammo types to Stun and they did not produce fire, nor damage to objects, nor permanent health damage. 

So maybe only ''ammo'' types (not weapon types) are allowed to generate area effects? (apart from Stun, as discussed immediately above).

[[User:Spike|Spike]] 19:39, 22 November 2008 (CST)

:It would be real fun if the blaster bomb could be turned into a huge area-of-effect ''stun'' bomb. :) -[[User:MikeTheRed|MikeTheRed]] 13:22, 24 November 2008 (CST)

== Field 0x2D (45) ==

This field used by AI for "Worth to take" estimation (function at address .text:004043E0). This value meant to be ''max_distance+5''.

  worthtotake = obdata_addr->field_2D;
  ...
  return (worthtotake - xc_BF_Get_Distance(v_Selected_Unit_Xpos, v_Selected_Unit_Ypos,
         a_ObPos_DAT[obj_num]->x, a_ObPos_DAT[obj_num]->y)) > 5;

I've patched ObData.Dat file (replaced all field_2d values of 0x01 with 0x10) and observed AI picking up dropped items. I don't know why this field was disabled, though I can presume it could be heavily used as "bait" like cheat because this estimation function cannot "skip" items if AI unit already has attacking weapons and clips (maybe this "taking" function ain't even called if unit is fully equiped - I didn't check that). Probably it wasn't finished... Which is weird. --[[User:Volutar|Volutar]] 08:07, 26 March 2011 (EDT)

:This is really good news that you found this function for aliens to pick things up . Finding a way to activate it could eliminate the silly problem of unarmed aliens who won't pick up weapons. You are right there is a risk of a "item bait" tactic being used. The trick would be to make sure that item pickup is only used by aliens who are unarmed or (better) for aliens who lack a weapon that is effective against X-Com, to pick up a weapon that ''is'' effective. [[User:Spike|Spike]] 17:28, 28 March 2011 (EDT)

As far as I tested it, this pickup function ain't used when alien have some attacking weapon. So there are no ways to use it as bait cheat. And actual code doesn't require any patching, only "obdata.dat" does. I wish to know the reasons why they made insufficient this "AI combat value" for attacking objects, because I don't see any. --[[User:Volutar|Volutar]] 21:59, 28 March 2011 (EDT)

:So if I understand correctly, if you set this ''worthtotake'' field to any value above 5, the alien will move to pick it up, if the alien is unarmed, and the (worthtotake of object - distance to object) is greater than 5? Excellent. [[User:Spike|Spike]] 15:19, 29 March 2011 (EDT)

If you set this field 10, maximum ''worth distance'' will be 5 (10-5), value of 20 will become 15 tiles (very valuable weapon, like blasterlauncher). Value of 5 will be ignored and 6 mean, alien willtake item only if he stands over it (occasionaly, or just dropped due to panic)...
The only presumable reason of disabling this AI feature is - it makes "panic unit" a bit obsolete, because there are small chances they won't take dropped weapon back...
Apart from this "worth distance" AI has another conditions for taking weapon from ground, so if you set this field to 200, they won't be ALWAYS running all over for weapon if they haven't one. When I set this field 10, about 70% of aliens were taken dropped weapons back at first turn, and about 90% at second...

:So two questions that come up are, 1, Who will do this mod?, and 2, what values to set? 
:Seb76 has said that he "doesn't do" data file fixes in his Loader, which is a shame. That means that we would want to prevail on BladeFireLight, the new maintainer of XComUtil, to incorporate this fix into a release of XCU. I do think it's fair to consider this a bug fix, though fixing it also doubtless "makes the game harder" (another category for XCU mods). At the moment, a Panicked alien is almost your ideal result in combat, at least against weapon-only aliens, because they are permanently disarmed and harmless. You can then use them for target practice, capture them, do what you like with no risk. 
:In my [[Talk:Alien_Inventory_Use#AI_Weapon_Preferences_Table|research on alien weapon preferences]], when their main weapon is missing or out of ammo, they select weapons out of their inventory more or less in priority of the base damage of the weapon (highest first). So it would be consistent, and simple, just to copy the base damage value into this field 24. Question: if there are multiple weapons out in the open, does the Alien go for the nearest one, regardless of the field 24 value, or will it go for a more distant weapon, if the 0x24 value is significantly higher? If there's no difference in behaviour, then it makes no difference, you might as well just set all the value to 0x10, as in your tests. If it does make a difference, then it might be best to set the 0x24 value to something like the Firepower Factor of the weapon, to help the Alien make the 'right' choice of weapon. Most of the time, the weapon with the highest base damage IS the best weapon to use against XCom, especially as XCom is often heavily armoured. It's not clear if the AI recognises that auto weapons and HE weapons are more effective than their base damage alone suggests. So you could tweak the 0x24 values to reflect that. [[User:Spike|Spike]] 06:15, 1 April 2011 (EDT)

Firstly it fills some buffer (maximum length is 50 elements) with items, having flag field (+0x0c) with bit1 set (& 0x02). Then it calculates most worthy item as maximum of ''worthToTake/(distance+1)''. And only after that it will try to pick this item up if distance is less than ''5-worthToTake''. So this value is matter when AI choosing object to pickup. And of course when AI sees some attacking options, it chooses most effective. When estimating grenade efectiveness it thinks that 1 friendly unit equal 2 enemy. So if there will be 1 friend with 2 enemies at very close distance, AI won't even try to blow them up.--[[User:Volutar|Volutar]] 12:55, 1 April 2011 (EDT)