Change MTL of OBJ while OBJ is already lodaded

Questions
1

Hey guys,

we work on an CAD Viewer and have now following Problem / Question.

We have OBJ Files which have more mtl files. (~3-4). We want to load the OBJ with the main MTL and if the User hit a button, we give the current OBJ a new MTL (Cause there are a view new Textures).

Is there a way to change the whole MTL?

The alternative is to analyse the mtl’s and send texture changes… But the first idea is much better xD

Thanks,
Daniel

2

Is it not simpler to generate the new material directly into your app rather than generate & loading another .mtl?

3

how does it mean?

4

Something like that: https://www.babylonjs-playground.com/index.html#95MJI8#37

(it’s weird, the .obj looks like broken here, but the logic is OK - [edit] yep, this .obj doesn’t have UV)

5

ah ok. Yeaj this is plan B.

Cause from the Customer we will get only OBJ / MTL files and before we split them, maybe there is a function that do this already. Something like this is also fine (but i can’t load a mtl? xD) MTLFileLoader - Babylon.js Documentation

But if there something like
OBJFile.changeMTL(“path to new mtl”) it will be a lot better, cause it’s smaller.

6

OK I see :slight_smile: About the MTLFileLoader you’re linking I can’t help, but it looks like you just have to use the parseMTL function using your new .mtl url isn’t it? Then just apply your new materials on your already loaded meshes.

7

maybe it is what i looking for.

But how does this work?
I don’t get it Run :confused:

8

ah now i have understood it.

I have analized the sourcecode on Github xD

  	$.ajax({
  		url : "./files/test.mtl",
  		dataType: "text",
  		success : function (data) {
  			var test = new BABYLON.MTLFileLoader();
  			
  			test.parseMTL(scene, data, "./files/");
  			console.log(test.materials);
  		}
  	});

First you need the MTL as TEXT (data). You will need your scene and you need the “dir” of the file (for Textures etc.)

9

Nice!

I tweaked my playground with your trick: Babylon.js Playground

(also, the rabbit mesh now have uv :wink: )

1 Like