RECV MODDING BASICS - TEXTURES - INTRODUCTION (By CBNJ)

[cbnj]

PREVIOUS GUIDE : RECV MODDING BASICS - MODELS - INTRODUCTION
https://www.dreamcast-talk.com/forum/vi ... 52&t=16986
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In the previous guide we gave claire a pretty shield, you clearly can see this shield its using her upper body texture and looks strange, well we will make it to look even more strange! But first, there is something else to know about that music disc 3d data we added to claire.

Opening our modified pl00.ald file in a hex editor we will make a string search for MDL two times, this will take us first to the claire body model start and next will take us to the secondary texture tables start, wich also have a MDL header, few bytes upwards is the 3d data for the music box disc we integrated to the model before.

[cbnj]

Locate the triangle strip table starter byte of the music box model by eye (8838) and go there, advance 3 bytes ahead leaving the triangle strip table starter byte (13250400) and the twin bytes (B2B2B2FF in this specific case) behind so your new location is 8844, you will have the value 08340040 in the byte you find your self now.
This byte will always control the calling number for the texture to use to wrap the 3d model, no matter wich model you are modifying or what numbers this byte can hold, this rule will never ever break for cv models.

[cbnj]

To succefully remap the texture our model will use we should split this byte in 4 segments of 2 bits each one so 08340040 will become 08 34 00 40
As you are probably thinking , yes every one of this numbers controls a specific function of the texture properties, and i should add it also controls some of the polygon properties too!

Since this guide is user friendly i wont describe what does each one of them but you better dont mess whit the 3 of them i wont explain (unless you want your model render totally black, derender your player by the console being unable to correctly render your model or drive your game to a chrash when trying to read your file since this bits have specific values to be inputted there and wont recognize or acept any other values exetp those specific ones)

You can see the third pair of bits is a double 00.
This double 00 are the texture caller bits wich tells the console what texture number use to wrap our 3d model in base to the texture table designed to be used for the model and only acept hex numbers as inputted values.
This and only this 2 bits in this specific byte are the texture callers no matter what values this byte can hold in the numerous models you can/could and will modify.

[cbnj]

Rigth now our music box disc is calling the texture numer 1 to wrap our music box disc as you can clearly notice by being holding the values 00, you can also deduce than the max texture numbre wich will fit here is FF (255).
Now that you know where is located the texture caller for every model we can face in CV and the range of textures it can use, its time to move to the guide section of this post.
END OF CHAPTER.

NEXT CHAPTER: RECV MODDING BASICS - TEXTURES - Ch.1 (By CBNJ)
https://www.dreamcast-talk.com/forum/vi ... 52&t=17007