シェーダーの置換に対するカメラのレンダーを作成します。
詳細は Rendering with Replaced Shaders を参照してください
If the replacementTag argument is not in use, pass an empty string as the value.
After calling this function, camera will render its view with shader replacement. Call
ResetReplacementShader to reset it back to normal rendering.
See Also: Rendering with Replaced Shaders, ResetReplacementShader, RenderWithShader.