Quick Modding/Hacking Answers Thread

npc.collision = [ecx+4]

?

flags that indicate which types of tile collision the entity is experiencing. Refer to the bottom of the compendium for more information. NPCs have a more basic collision code so they can only tell sides slopes and water iirc

Two questions:
1. How would I make an NPC be in front of the player instead of behind (With the player standing still)?
2. What is the best way to put the player in a spesific position without teleporting them there
(IE talk to an NPC then put the player a set distace away from that NPC before talking to them)?

1) you can't
2) <MOV, or <MYB if you just want it to be a little distance

 

...1) you can't...

I may have just found a work around for my problem.

...<HMC<FL+0205<ANP:Animation stuff goes here...



Entity

Type = 150 (Quote)

Flags = 0800

Event# 205



Only problem i'm having now is Quote not appearing.

Does the map need to reload to make Quote appear?

 

How do the logic instructions (and, or, xor, not) work when placed before conditional jmp's?



mov eax, npc.collision
and eax, 8
jz :Render

Does it do the same thing as je, jge, jle, jl???

I know jz = je, but it's the and before that I can't understand.


(and google/win calculator is not helping)

 

How do the logic instructions (and, or, xor, not) work when placed before conditional jmp's?

mov eax, npc.collision
and eax, 8
jz :Render

Does it do the same thing as je, jge, jle, jl???

I know jz = je, but it's the and before that I can't understand.


(and google/win calculator is not helping)

I'm a bit short on time right now, so I'm just going to say that most of your question should be answered by lessons 36 and 37 of Carrotlord's beginner's guide to assembly. He explains it better than I would even if I had time to explain it.

 

(Sorry if this doesn't belong here.)
As far as I have understood, in .pmd format the file itself contains 3 different sounds. If so, is it possible to isolate these in a separate .wav (or other) file?

Thank you in advance.

 

i forgot how much ass assembly sucked

CPU Disasm
Address   Hex dump          Command                                  Comments
00424E66  |.  8B15 E05A4A00 MOV EDX,DWORD PTR DS:[4A5AE0]
00424E6C  |.  83C2 04       ADD EDX,4
00424E6F  |.  52            PUSH EDX                                 ; /Arg1
00424E70  |.  E8 8BCAFFFF   CALL 00421900                            ; \Doukutsu.00421900
00424E75  |.  83C4 04       ADD ESP,4
00424E78  |.  8945 DC       MOV DWORD PTR SS:[EBP-24],EAX
00424E7B  |.  0FBE45 DC     MOVSX EAX,BYTE PTR SS:[EBP-24]
00424E7F  |.  3905 0C5B4A00 CMP DWORD PTR DS:[4A5B0C],EAX
00424E85  |.  74 14         JE SHORT 00424E9B
00424E87  |.  0FBE4D DC     MOVSX ECX,BYTE PTR SS:[EBP-24]
00424E8B  |.  890D 0C5B4A00 MOV DWORD PTR DS:[4A5B0C],ECX
00424E91  |.  C705 105B4A00 MOV DWORD PTR DS:[4A5B10],800
00424E9B  |>  8B15 E05A4A00 MOV EDX,DWORD PTR DS:[4A5AE0]
00424EA1  |.  83C2 08       ADD EDX,8
00424EA4  |.  8915 E05A4A00 MOV DWORD PTR DS:[4A5AE0],EDX

i've been looking through the <FAC code, but i'm confused. it doesn't seem to CALL or anything to result in the image rendering. I'm probably just really shitty at assembly but i was wondering if someone could help me out.

Also is there a better way to find the framerects of a particular object bc trying to search for a constant value throughout the entire executable really isn't optimal

 

Are

npc.movex=[ecx+10]
npc.movey=[ecx+14]

Just variables? (they don't seem to do anything by themselves)

 

Only problem i'm having now is Quote not appearing.
Does the map need to reload to make Quote appear?

well remember that what <hmc DOES is make quote invisible. if you want to make him visible again, you need to use <smc.

How do the logic instructions (and, or, xor, not) work when placed before conditional jmp's?

mov eax, npc.collisionand eax, 8jz :Render

Does it do the same thing as je, jge, jle, jl???
I know jz = je, but it's the and before that I can't understand.

I prefer using jz to je myself, because it gives a much clearer idea of what's happening. basically, the cpu has a bunch of special flags it uses for various things, one of which is the z flag (set if the result of an operation is zero), and one of which is the negative flag (set if the result is negative).

So calling jz after and just sees if the result is zero. you can obviously do the same thing after sub, or cmp (which is sub except instead of storing the result of the subtraction, it only sets the flags). jl would see if the negative flag was said, jle if the negative or zero flags, jg if the negative flag wasn't set, etc. etc.

grok?

*snip*
00424E78  |.  8945 DC       MOV DWORD PTR SS:[EBP-24],EAX
00424E7B  |.  0FBE45 DC     MOVSX EAX,BYTE PTR SS:[EBP-24]
00424E7F  |.  3905 0C5B4A00 CMP DWORD PTR DS:[4A5B0C],EAX
00424E85  |.  74 14         JE SHORT 00424E9B
00424E87  |.  0FBE4D DC     MOVSX ECX,BYTE PTR SS:[EBP-24]
00424E8B  |.  890D 0C5B4A00 MOV DWORD PTR DS:[4A5B0C],ECX
00424E91  |.  C705 105B4A00 MOV DWORD PTR DS:[4A5B10],800
*snip*

i've been looking through the <FAC code, but i'm confused. it doesn't seem to CALL or anything to result in the image rendering. I'm probably just really shitty at assembly but i was wondering if someone could help me out.

[4a5b0c] is a global var that holds the id of what face should be drawn. the drawing is handled elsewhere. you can figure this out by seeing that eax holds the argument of <fac and seeing that the only thing done with it is that it's put into that variable.

note that [4a5b10] only gets a value if the face changes from one id to another. I'd guess it has something to do with the animation that changes between faces. (possibly an x offset from the norm - I don't recall cuz it's been forever, but I believe the faces slide in)

Are

npc.movex=[ecx+10]npc.movey=[ecx+14]

Just variables? (they don't seem to do anything by themselves)

yes....
tho I don't get what you mean by "just variables" -- nothing does anything by itself, and any time you put a number into memory you're storing it into a "variable" of some form or another

 

yes....
tho I don't get what you mean by "just variables" -- nothing does anything by itself, and any time you put a number into memory you're storing it into a "variable" of some form or another

I think he's asking if they are actually utilized anywhere in the code outside of the AI functions, by which the answer is no as far as I can remember

 

So... I'm new to ASM. I'm following Carrotlords guide for ASM, I've had previous coding experience, so I feel like I'm overlooking something really obvious. So basically I'm doing the lesson on NPC hacking, and it all makes sense. However I'm not quite sure how Carrotlord got the offset for NPC 2 (Behemoth). I know I'm supposed to use the assembly compendium from noxid. The offset is 426AF0 as said in the guide. When I look up the offset in the compendium it's 0x00265B0 which is hex. How do I get 426AF0 from 0x00265B0?

 

well for one, you're reading the compendium wrong. It's zero-indexed, so the listing you gave is for NPC0001
second of all, if it doesn't start with a 4 then probably add 0x400000 to it. This is because of inconsistency in whether people wanted to record the physical address or the virtual address.
thirdly I'd recommend using the functionlist.txt for finding function addresses as it's more recent than the compendium anyway

 

1. Oh. I feel dumb. Not that it mattered
2. Oh. That makes sense I guess.
3. Will do.

Thanks

 

Is it possible to add recoil to the lvl3 Bubbler thorn-like things/bullets (when shot downwards), so they behave like the lvl3 Machine Gun?
Thank you in advance.

 

You mean, when holding X and shooting, or when the bubbles pop?

 

When the bubbles pop.

 

how would i be able to change how much fuel the 0.8 has? like, if its maximun height is 6 blocks (i think) i'd want it to be at 8 blocks then. does that make sense?

 

You cant't change the max fuel of one booster without changing the other.

The RAM address is...

[49E6E8]

there...knew I had it somewhere in my notes.

 

but... how do i change it? there doesnt seem to be any way to change it, atleast from what i got. it says "ADD BYTE PTR DS:[EAX],AL" which i don't understand.

 

but... how do i change it? there doesnt seem to be any way to change it, atleast from what i got. it says "ADD BYTE PTR DS:[EAX],AL" which i don't understand.

Try looking at the address in the hex dump.

 

That's the offset that you're looking at. You want the ram address, so you'll have to search > constant > "49E6E8" to find where the variable is set and checked.
You should probably be using ollydbg for this