Remove duplicate materials & textures

[Biscuit]

Hello. I have a scene where multiple GLTFs are dynamically loaded, each with various materials, some of which are shared between them. I initially tried removing only the duplicate textures, since I noticed that some GLTFs, even when using the same source for both emissive and albedo channels, create separate textures for each channel in Babylon.js. This approach seemed to work initially.

However, I later realized that some materials were also duplicated, so I tried applying the same approach to materials, but for some reason, it doesn’t work — the duplicate material isn’t removed as expected. Additionally, in some cases, the scene.ready trigger doesn’t seem to be invoked, causing the scene to hang in a loading state indefinitely.

Any suggestions would be greatly appreciated.

ps: I read about a potential approach where I could load one GLTF containing only the materials, and then load the other GLTFs without materials, assigning the materials afterward. Unfortunately, this doesn’t really apply in my case because I’m not sure exactly which materials will be used across the GLTFs being loaded. Out of a library of 100 materials, only about 10 might actually be used, so loading the entire library just for a subset would be inefficient.

Babylon.js Playground

You can check the console to see the logs.
Thank you again for your help!

[labris]

A couple of useful threads:

How to avoid duplicate materials with multi asset loading

Hi All So I have a scene that loads many different assets into it. Many assets have same named materials and it is meant to be this way. So if I change the material texture , it shouldd update all assets using that material. Of coarse I noticed this was not happening and so logged the materials array of the scene and noticed many instances of the said single material , instead of one. So my question is how do I load an asset and when it loads it does not create a duplicate material , but rath…

Preventing duplication of materials and textures on a library of GLTF models

We’re working on building a library of 3d assets, and wondering what the best strategy in Babylon is for re-using textures as much as possible. Our 3D assets share a common set of textures. Let’s say there are around 100 textures in the game, and all of our GLTF models share them. Exporting from Blender and loading the GLTFs in the game results in each unique model loading a unique copy of the textures it uses, and I’m guessing that’s going to hurt performance and burden low-end devices as our …

[MarianG]

Hey, found why the materials are not disposed

BabylonJS/Babylon.js/blob/87497f376bdbd326dc5d5dfe9318d9fc20d5211f/packages/dev/core/src/Materials/pushMaterial.ts#L28

I think you don’t need to check if the material is ready before to dispose, or if you want ot check if it is ready you need to put a mesh as param else the function return false all the way.

Babylon.js Playground

line 107
About your second issue related scene.ready I have no idea

[Joe_Kerr]

I have tackled this recently. There are at least 4 options I can think of:

1. Intercept materials/textures on load
2. Assign ids via gltf extras property
3. Use material.name as id
4. Reference counting

The advantage of 1 is that you do not instantiate materials/textures. But, as shown below, you might need to override a private method which is gonna get ugly.

Below is an example for 1. See the link for other overridable methods.

var defaultMaterialSingleton = null;
// See https://github.com/BabylonJS/Babylon.js/blob/master/packages/dev/loaders/src/glTF/2.0/glTFLoader.ts#L2151
export default function override(BABYLON) {
    const defaultCreateDefaultMaterial = BABYLON.GLTF2.GLTFLoader.prototype._createDefaultMaterial;
    BABYLON.GLTF2.GLTFLoader.prototype._createDefaultMaterial = function(name, babylonDrawMode) {
        if (typeof name === "string" && name.startsWith("__GLTFLoader._default")) {
            if (defaultMaterialSingleton === null) {
                this._babylonScene._blockEntityCollection = !!this._assetContainer;
                defaultMaterialSingleton = new BABYLON.BackgroundMaterial("GLTFEmptyMaterial"); //#todo is this the cheapest material possible?
                this._babylonScene._blockEntityCollection = false;
                defaultMaterialSingleton.fillMode = babylonDrawMode;
                defaultMaterialSingleton.freeze();
            }
            defaultMaterialSingleton._parentContainer = this._assetContainer;
            return defaultMaterialSingleton;
        }
        return defaultCreateDefaultMaterial.call(this, name, babylonDrawMode);
    };
}

For 2 beware that you cannot set extra properties on textures

For 3, well it is a name not an id. Ensure that nothing touches it.

For 4, I mean whether a texture is used by any material and whether a material is used by any mesh. Works as long as you do not preload (and don’t assign) materials/textures for later use.

[labris]

@Joe_Kerr

3. Use material.name as id

When one has control over asset and materials kit (ie all materials with the same name are the same) - this is the best option.

[riven04]

Should there be a built-in way to check isReady bypassing the mesh check? For material management it makes sense to have an option to do this.

[MarianG]

I have no idea

[Biscuit]

Hey, thank you all.
I uesd MarianG idea to partialy fix my function, but I’ll trry to use Joe idea as well and Intercept materials/textures on load.