Material SphereMaterial;

    // Use this for initialization
    void Start()
    {
        SphereMaterial = Resources.Load<Material>("Materials/man");
        if (SphereMaterial == null) Debug.Log("mat null");
        else Debug.Log("mat not null");
        Debug.Log("new Material: " + SphereMaterial.name);
        MeshRenderer meshRenderer = GetComponent<MeshRenderer>();


        // Get the current material applied on the GameObject
        Material oldMaterial = meshRenderer.material;
        Debug.Log("Applied Material: " + oldMaterial.name);
        // Set the new material on the GameObject
        meshRenderer.material = SphereMaterial;
    }

public class ButtonHandler : MonoBehaviour {


    public void ButtonInteract()
    {
        Debug.Log("changing matriel ");
        // Change the material of the game object here

    }
}