How to get the correct material and texture asset id?

Hi, I’ve tried to get the asset ID of the resources from an existing entity which has texture and material set up.

I can successfully get the resource id of the model and sound clip like this:
this.modelID = this.entity.model.asset;
this.soundID = this.entity.sound.slot(‘Slot 1’).asset;

but I got problems while I tried to get the resource id of the material and texture,
tihs is the code refering to mat & tex:

this.texID = this.entity.model.meshInstances[0].material.diffuseMap;

is there anything wrong with it?