Need help regarding reverse engineer a model file

[Silence Exterminator]

3 hours ago, Bigchillghost said:

It's really difficult to read your comment due to the lack of necessary punctuations and I always seem to lost focus on what you're actually trying to express. So I'm serious about this:

 

So why did you wrote the entire normal buffer from offset 0x8050 instead of one per vertex element?

file.seekp(32848);
int count = 0;
for (const auto& normal : normals) {
    if (count >= 2848) {
        break; // Reached the limit
    }
    for (float component : normal) {
        char byte = static_cast<char>((component + 1.0f) * 127.0f); // Convert float to Byte range
        file.write(&byte, sizeof(char));
    }
    // #### file.seekp(0x15, ios::cur) is required here!!! 0x15 == 24 - 3 bytes for the written normal
    ++count;
}

And what's this "remainingBytes" for and why did you insert the AB 00 00 00 pattern repeatedly?

// Check if we need to move to the next pattern
int bytesInjected = count * 12;
int remainingBytes = 32848 - 20 - bytesInjected;
if (remainingBytes > 0) {
    file.seekp(bytesInjected, std::ios::cur);
    for (int i = 0; i < remainingBytes; ++i) {
        char patternByte = (i % 4 == 0) ? 0xAB : 0x00;
        file.write(&patternByte, sizeof(char));
    }
}

 

The "blue" are the normal plus the tangent, the leading zero bytes might be an unused vertex color channel.

 

Something like:

uint8_t aByte = 0;
file.read((char *)&aByte, 1);
float toFloat = (aByte / 255.0) * 2.0 - 1.0;

 

Not sure what you mean by that. You hard-coded the address and count but expected it to be generic?

hi bro how are u thanks for replying, I was just trying to implement custom normal injection into the game from an obj file. An attempt for injection biscally to change the mesh in game. I did that successfully but normals were very badly looking in game, so i tried to inject normals from obj file but doesn't seem to work very well, but now as u provided me the code piece i can work on it and let u know, thanks again

[shak-otay]

On 5/24/2024 at 11:20 AM, shak-otay said:

The normals might be compressed in the vertex block, 2 x DWORD, aabbccFF, 2x24= 48 bits?

@roocker666: well, seems I was right with my first assumption...

edit: so normals, not vertex colors.

edit2: Bigchillghost made it clear that it's 8 bit normal's components (last Friday)

Edited June 3 by shak-otay
@ added