# How to keep Texture Sample empty? **URL:** \ **Category:** Asset Creation\ **Tags:** unreal-engine, question\ **Created:** [January 4, 2016, 4:03pm UTC](https://forums.unrealengine.com/t/how-to-keep-texture-sample-empty/343066 "2016-01-04T16:03:28Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Erigo](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Erigo](https://forums.unrealengine.com/u/Erigo)\ **Post date:** [January 4, 2016, 4:03pm UTC](https://forums.unrealengine.com/t/how-to-keep-texture-sample-empty/343066/1 "2016-01-04T16:03:28Z")
Hey guys, How can I keep a Texture Sample empty ? For instance I want to create a master Material for further usage for instancing and I want to have an option for Normal map to use detail Normal Map over my Normal Map, but not always, some times I want to leave in my instance this option not in use, just blank, so to keep normal map with no detail NM feature applied. Is it possible or I have to create two materials with features for detail maps and without ? ---
**Author:** ![Mercurial\_Forge](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/mercurial_forge/32/872818_2.png) [@Mercurial\_Forge](https://forums.unrealengine.com/u/Mercurial_Forge)\ **Post date:** [February 20, 2016, 6:06pm UTC](https://forums.unrealengine.com/t/how-to-keep-texture-sample-empty/343066/2 "2016-02-20T18:06:43Z")
Use a switch parameter and pass the texture smaple in through the true, and a vector3 (0,0,1) (default normal) through the false. Now you can chose with each instance if it uses detail normals or not at all. > **[Parameter Expressions](https://docs.unrealengine.com/4.27/en-US/RenderingAndGraphics/Materials/ExpressionReference/Parameters/)** > > Expressions that expose properties to Material Instances to be overridden in child instances or modified at runtime.