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U3D Resources Issues; is it safe?
Topic Started: Oct 6 2008, 01:30 PM (378 Views)
SonicMX
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Surely most of you have though about this, but I don't really find a good method.
If you had a game and you gave it to a friend, and then he changes a map file, or U3D file for another one, it will surely be loaded instead of the original one.
Unless I used a string of the file to know it is the truth one, there aren't much more ideas.
Like: Check that the texture: "material01___" exists inside of the model.
Or would it be possible to use the notepad and then check any line by copying a piece of it inside Game maker?
And the last idea would be to send the files to the temp directory, but I don't really know if they can be caught while they are there o__o.

Soy español de España, y malo en mates, y.. ¿intento hacer un juego? estoy loco xD
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ashrat3000
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u3d raytracer
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Well, if you use the U3D file format, then you can't just replace the model.
It has a password.
Your friend would need to know the password.

Of course, this password could probably be cracked, but definitely not by your average fellow.


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skarik
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kitten eating scum
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What's wrong with editing resources?

http://video.google.com/videosearch?um=1&hl=en&q=zelda%20in%20half%20life&ndsp=18&ie=UTF-8&sa=N&tab=iv#
Blog|EHS
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ashrat3000
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u3d raytracer
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Ahahaha
That is awesome.

Now I have to try something like that. Maybe replace Barnie with Mario or something.

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skarik
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Yeah, when I still had my old PC, I replaced pretty much all the weapon models in the original Half Life. Good 'ol days with 3dsMax 3 being the latest ever...

Yup, that was good 'ol sixth and seventh grade.
Blog|EHS
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SonicMX
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ok, then.. I have to put a single password per file. (I obviously don't want anyone to change anything), didn't know U3D checks even when password is "".
Thankies!
Soy español de España, y malo en mates, y.. ¿intento hacer un juego? estoy loco xD
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Dr. Best
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SonicMX
Oct 7 2008, 01:18 AM
didn't know U3D checks even when password is "".
It does not. An empty string as password is equivalent to having no password at all.
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SonicMX
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Quote:
 
An empty string as password is equivalent to having no password at all.

But it can't be nothing, otherwise, how does U3D compare when the file has the same pass?
By checking if both doesn't exists or if already one exists? (Might be.. xDU)
Edited by SonicMX, Oct 7 2008, 01:29 AM.
Soy español de España, y malo en mates, y.. ¿intento hacer un juego? estoy loco xD
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Dr. Best
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I do not get your question, but maybe the following text will answer it:
*.u3d files can be either encrypted or unencrypted. If you use an empty string as password the created *.u3d file is unencrypted. If you pass a password for loading an *.u3d file it will get decrypted using this password, if you do not give a password the data is used as it is found in the file. After that the loading process starts, by checking whether the file starts with a valid *.u3d file identifier. If it finds that identifier, this means that the file has been decrypted correctly (or was already unencrypted). If it does not find it Ultimate 3D knows that the file has not been decrypted correctly, so the password must have been wrong.
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SonicMX
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now it's clear! :P Thanks!
Soy español de España, y malo en mates, y.. ¿intento hacer un juego? estoy loco xD
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luenardi
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Cofee Machines Rock
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Just Be careful i screwed my self the other day when without thinking i added a password and then i forgot it..
oops.
trying to decypher it was hell as i have no idea how DR.Best did the encryption. and no i will not work futher on this.
Posted Image

For your perception no.
But my universe has no such limits.


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Dr. Best
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Hehe. I know how the encryption works since I made it, but still I would most likely not succeed, if I would try to decrypt it without a password ^_^ . The encryption is not that complex. Simple password dependent permutation and per byte substitution. You could probably get somewhere by analyzing byte frequencies, but even that would be difficult since it is a binary file format. I recently considered encrypting a file and posting it somewhere without giving the password. The person who would be able to tell me what is in it would have got 20€ through paypal or something like this, but nobody on that forum would have succeeded anyway :D .
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luenardi
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Doc i respect your work this is why i droped it. ;) the only way i keep my work secret is if i and others don't pursue this.
We will only be screwing our self.
Posted Image

For your perception no.
But my universe has no such limits.


www.recall.co.nr
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Reikyrr
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luenardi
Oct 7 2008, 07:55 PM
Doc i respect your work this is why i droped it. ;) the only way i keep my work secret is if i and others don't pursue this.
We will only be screwing our self.
*Spanks Luenardi telling him to respond to PM.

So are U3d files some sort of zipfiles? (yeah im bad with ultra well written manuals. They must be extremely well written to be understandable for me..)
~Inspirational quote~
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Dr. Best
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Well, they can contain complete texture files, but other than that they have nothing in common with zip files. I am not using any library for zip files or something like this. The Ultimate 3D model file format (*.u3d) is a file format, which can handle models among with the other needed information (textures and shaders).
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