BabylonJS/Babylon.js · error

${extraContext}: Material type not supported

Error message

${extraContext}: Material type not supported

What it means

MSFT_minecraftMesh requires the loader to have created a PBR material implementation, since it applies its extra properties on top of the 'pbr' metal-rough workflow. loadMaterialPropertiesAsync looks up _loader._pbrMaterialImpls.get('pbr'); if the material is not a PBR metallic-roughness material (or the PBR implementation wasn't registered), it throws.

Source

Thrown at packages/dev/loaders/src/glTF/2.0/Extensions/MSFT_minecraftMesh.pure.ts:40

    /** @internal */
    constructor(loader: GLTFLoader) {
        this._loader = loader;
        this.enabled = this._loader.isExtensionUsed(NAME);
    }

    /** @internal */
    public dispose() {
        (this._loader as any) = null;
    }

    /** @internal */
    // eslint-disable-next-line no-restricted-syntax
    public loadMaterialPropertiesAsync(context: string, material: IMaterial, babylonMaterial: Material): Nullable<Promise<void>> {
        return GLTFLoader.LoadExtraAsync<boolean>(context, material, this.name, async (extraContext, extra) => {
            if (extra) {
                const impl = this._loader._pbrMaterialImpls.get("pbr");
                if (!impl) {
                    throw new Error(`${extraContext}: Material type not supported`);
                }

                const promise = this._loader.loadMaterialPropertiesAsync(context, material, babylonMaterial);

                if (babylonMaterial.needAlphaBlending()) {
                    babylonMaterial.forceDepthWrite = true;
                    babylonMaterial.separateCullingPass = true;
                }

                babylonMaterial.backFaceCulling = babylonMaterial.forceDepthWrite;
                (babylonMaterial as PBRMaterial).twoSidedLighting = true;

                return await promise;
            }
        });
    }
}

View on GitHub (pinned to 0592b347b8)

Solutions

1. Ensure materials with MSFT_minecraft_mesh use the pbrMetallicRoughness workflow.
2. Remove the MSFT_minecraft_mesh extension from non-PBR materials.
3. Re-export the asset converting unlit/spec-gloss materials to metallic-roughness.

Example fix

// before: unlit material with the extension
"materials": [{ "extensions": { "MSFT_minecraft_mesh": {} }, "KHR_materials_unlit": {} }]
// after: PBR material keeps the extension
"materials": [{ "extensions": { "MSFT_minecraft_mesh": {} }, "pbrMetallicRoughness": { "baseColorFactor": [1,1,1,1] } }]

const isPbr = material.defs?.some(d => d.name === 'pbrMetallicRoughness') || !material.extensions?.KHR_materials_unlit;
if (!isPbr) throw new Error('MSFT_minecraft_mesh requires PBR metallic-roughness materials');

function isPbrMaterial(m: IMaterial): boolean {
  return !m.extensions?.['KHR_materials_unlit'] && !m.extensions?.['KHR_materials_pbrSpecularGlossiness'] && 'pbrMetallicRoughness' in m;
}

try { await loader.loadAsync(url); } catch (e) {
  if (e.message.includes('Material type not supported')) {
    // convert the material to metallic-roughness or strip the extension, then retry
  } else throw e;
}

When it happens

Trigger: Loading a glTF where a material carries the MSFT_minecraftMesh extra but the material is not PBR metallic-roughness — e.g. it uses KHR_materials_unlit, spec-gloss (KHR_materials_pbrSpecularGlossiness), or another workflow.

Common situations: Assets mixing MSFT_minecraft_mesh with unlit or legacy specular-glossiness materials; converting assets between workflows and keeping the extension; custom loaders that don't populate the PBR implementation map.

Related errors

• No PBR material implementation loaded
• Cannot get the last selected variant on a glTF mesh that doe
• nodeIndex not found in configuration
• nodeIndex not found in configuration
• ${extensionContext}: Texture type not supported

AI-assisted analysis of BabylonJS/Babylon.js@0592b347b8 (2026-08-30). Data as JSON: /api/errors/3057c117f2bf3687. Report an issue: GitHub.