HideFlags.HideAndDontSave

설명

Objects are not shown in the hierarchy, not saved to the scene and is not unloaded by Resources.UnloadUnusedAssets.

This is commonly used for objects that are created by scripts and are purely under their control.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {

	// Creates a material that is explicitly created & destroyed by the component.
	// Resources.UnloadUnusedAssets will not unload it, and it will not be editable by the inspector.
	private Material ownedMaterial;
	void OnEnable() {
		ownedMaterial = new Material(Shader.Find("Diffuse"));
		ownedMaterial.hideFlags = HideFlags.HideAndDontSave;
		GetComponent<Renderer>().sharedMaterial = ownedMaterial;
	}

	// Objects created as hide and don't save must be explicitly destroyed by the owner of the object.
	void OnDisable() {
		DestroyImmediate(ownedMaterial);
	}
}