Qt3d Sceneloader: Replace the material component of an Entity with my custom material at runtime

[ruisebastiao]

i have the following code to load a collada scene using the SceneLoader:

SceneLoader{
    id: sceneLoader
    source: "file:///home/rui/projects/cad/bodyplacement_lm36_v2.dae"
    
    
    MetalRoughMaterial {
        
        id:metal_mat
        objectName: "MetalRoughMaterial"
        
        metalness: 0
        roughness: 0.9
    }
    
    
    onStatusChanged: {
        console.log("SceneLoader status: " + status);
        if (status == SceneLoader.Ready) {
            console.log("Scene is ready");
            
            var entitynames=sceneLoader.entityNames();
            for (var i = 0; i < entitynames.length; ++i) {
                
                var entityname=entitynames[i];
                var entityvar=sceneLoader.entity(entityname);
                
                for (var j = 0; j< entityvar.components.length; ++j) {
                    
                    
                    var cmp=entityvar.components[j]
                    if(cmp){
                        var cmp_class=cmp.toString();
                        if(cmp_class.indexOf("QPhongMaterial")>=0){
                            entityvar.components[j]=metal_mat;
                        }
                        
                    }
                    
                    
                    
                }
                
                
                
            }
            
            
            
        }
    }
    
    
    
    
}

as stated in docs (https://doc.qt.io/qt-5/qt3drender-qsceneloader.html#details):

The loader will try to determine the best material to be used based on the properties of the model file. If you wish to use a custom material, you will have to traverse the tree and replace the default associated materials with yours.

after i iterate all the entities i try to replace the material component wit the code:

entityvar.components[j]=metal_mat;

but isn't working. After debugging i can see that the loaded material isn't replaced.

How can i replace the material component with my custom material at runtime?