Reflections using local cubemaps
You can create reflections using local cubemaps. This method avoids creating the reflection texture each frame, instead it fetches the reflection texture from a prerendered cubemap. This method applies a local correction to the reflection vector based on where the cubemap was generated and the scene bounding box, and uses that information to fetch the correct texture.
Reflections that are generated using local cubemaps do not suffer from pixel instability or pixel shimmering that can occur when a reflection is generated at runtime for each frame.
For more information on reflections using local cubemaps, see Implementing reflections with a local cubemap.