Some of gltf's children mesh seems can't be "modified"

[JohnConstantine]

Hello guys!
Today i tried to modify some gltf model by changing it’s material.

new GLTFLoader().load('./resources/loader/M1A2/scene.gltf',gltf=>{
    gltf.scene.scale.set(0.01,0.01,0.01)
    this.scene.add(gltf.scene)
    gltf.scene.traverse(e=>{
        console.log(e.type)
        if(e.isMesh || e.isSkinnedMesh){
            const parent = e.parent
            parent.remove(e)
            parent.add(new THREE.Mesh(e.geometry,new 
                THREE.MeshLambertMaterial({color:0xFFFF99}) ))
            }
        })
})

But some meshes remain their original material.

original

modified

[Mugen87]

@JohnConstantine

 const parent = e.parent
            parent.remove(e)
            parent.add(new THREE.Mesh(e.geometry,new 
                THREE.MeshLambertMaterial({color:0xFFFF99}) ))
            }

Please do not modify object hierarchies in traverse operations. It seems you only want to update materials so consider to do this:

if(e.isMesh) {

    e.material = THREE.MeshLambertMaterial({color:0xFFFF99});

}

[JohnConstantine]

@Mugen87

e.material = THREE.MeshLambertMaterial({color:0xFFFF99});

Thx , it do solve this question.
However , I need to modify object somehow , cause I actually want to do csg which returns me a new mesh

[JohnConstantine]

Ah! Never mind my last comment , I just implement this like you said.

const mesh = csg(e)
e.geometry = mesh.geometry