To make use of the reflection cubemapA collection of six square textures that can represent the reflections in an environment or the skybox drawn behind your geometry. The six squares form the faces of an imaginary cube that surrounds an object; each face represents the view along the directions of the world axes (up, down, left, right, forward and back). More info
See in Glossary, an object must have the Reflection ProbesA rendering component that captures a spherical view of its surroundings in all directions, rather like a camera. The captured image is then stored as a Cubemap that can be used by objects with reflective materials. More info
See in Glossary option enabled on its Mesh RendererA mesh component that takes the geometry from the Mesh Filter and renders it at the position defined by the object’s Transform component. More info
See in Glossary and also be using a shaderA program that runs on the GPU. More info
See in Glossary that supports reflection probes. When the object passes within the volume set by the probe’s Size and Probe Origin properties, the probe’s cubemap will be applied to the object.
You can also manually set which reflection probe to use for a particular object using the settings on the object’s Mesh Renderer. To do this, select one of the options for the MeshThe main graphics primitive of Unity. Meshes make up a large part of your 3D worlds. Unity supports triangulated or Quadrangulated polygon meshes. Nurbs, Nurms, Subdiv surfaces must be converted to polygons. More info
See in Glossary Renderer’s Reflection Probes property (Simple, Blend Probes or Blend Probes and Skybox) and drag the chosen probe onto its Anchor Override property.
See the Reflection Probes section in the manual for further details about principles and usage.