https://ibb.co/bZRXrx (link of a shirt image). I want to change the fabric of the arm sleeve, while the fabric on the body doesn’t change. I know it is possible to change part of a mesh/model using UV uwrapping, my question is are there other methods to use to achieve this. I am afraid that if i have 200 fabrics, i have to make 200 different UV on wrapping with blender.
I’m not a 3D modeler but I know that tools like Blender are able to assign materials to a selected group of faces. In this way, you can create a multi material object and thus independently apply surface modifications to certain parts of the mesh. This makes it also possible to apply multiple diffuse texture to a single object.
There is no need of having more than one set of UV coordinates usually. these just describe unwrapped 2D positions of the vertices in order to apply a texture. As @Mugen87 said, you can either select the wanted faces and apply the different materials for using a multi material, or just separate each part of the model.
If the sleeve for example could be changed with another shaped one, you would rather use each part as separate model.
if i understand you correctly, you mean it is possible to tell threejs to get the positions of the vertices (the vertices of the arm) i want the texture to cover and then apply the texture on it ?
When you apply different materials on the same geometry in tools like blender or C4D, the exporter (if supported) will group them in order to use a multi material in THREE then, but it might also just split the geometry into these groups, depending on how it deals with it.
UV only describes the faces of your geometry in 2D space in a reasonable arrangement (hence the unwrapping), the shader/material will apply any texture you provide. It only tells each vertex where it is on any texture provided.
I want to change the fabric of the arm sleeve, while the fabric on the body doesn’t change.
Define the term “fabric” please. It is ambiguous in terms of 3d graphics and rendering. It could be a red fabric changing into a green fabric. Or black silk changing into black polyester etc.
Instead of taking stabs at this particular ask “i have a shirt, a sleeve and a fabric”, you need to understand better how 3d graphics work and what they are made out of.
For example, does the shirt need to be made out of a single mesh, or could it be multiples. Could shirt be a THREE.Group instead of a mesh, while body, sleeve_left etc are meshes.
Do you need to use uvs at all, or can you maybe use vertex colors, etc.
By fabric I mean things like (color or the png/jpg image wrapping it). My first intention was to make the shirt a THREE.Group while the sleeve, collar, button and others will be meshes which make up the group, but then I am a bit skeptical of having to place each part of the shirt which are the mesh perfectly together to make it look like they aren’t separate object this is because Three.js has no visual designer.
but then I am a bit skeptical of having to place each part of the shirt which are the mesh perfectly together to make it look like they aren’t separate object this is because Three.js has no visual designer.
Well thats at least easy to answer. It’s not your job to do it. It’s the job of whomever is providing the asset. If they gave you an asset that you can’t align, there is no way you can do the assembly perfectly yourself. (well there is but extremely involved).
By fabric I mean things like (color or the png/jpg image wrapping it).
In terms of 3d / graphics, i believe you are talking about a “texture” and a “color”. What type of texture ( or textures ) it is would answer all the questions about uv mapping, and possibly the assembly as well.
In which case it might be useful to share that texture.
Textures such as JPG images of clothes something like this(https://ibb.co/mxrZrx) or a denim material, i am trying to achieve this site https://www.tailorstore.com/uniform-shirt-designer#Fd8ZBAbEAcm8vwEG|lc2JNCKyFq3PhXQy60z9f9NT989lpRxD in 3D or in any other efficient way. And secondly, is the only way to fit each mesh perfectly on each other through trial and error (how do i know which position in 3D space to fix them so they can be aligned ? )
Yeah for something like that, just a repetitive texture of a fabric you need exactly one UV set. Things like sleeves could even save the same UV space. Your problem here is quite simple, you need to break apart these meshes “somehow”.
The most straightforward thing is to break it apart into meshes.
Again, through trial and error you still wont be able to align it perfectly. Again, it has to be done through something that has the appropriate tools to do that. Blender for example, would have the ability to move a mesh around a scene, and snap a vertex onto another vertex.
You, as an engineer, have an expectation that someone would already do that for you and provide the asset.