You can use a bitmap file or procedural map to control the reflectivity of an object surface.
Using a Reflection map
You can use three kinds of Reflection maps: basic, automatic, and flat-mirror.
Another way to generate reflections automatically is to assign a Raytrace map to be the reflection map.
The most common use of Reflection maps in a realistic scene is to add just a touch of reflection to an otherwise non-reflective surface. By default, Reflection map strength is 100 percent, as it is for other maps. For many kinds of surfaces, however, reducing the strength gives the most realistic result. A polished table top, for example, primarily shows a wood grain; the reflections are secondary.
Reflection maps don't need mapping coordinates because they're locked to the world coordinate system, not to the geometry. The illusion of a reflection is created because the map doesn't move with the object, but with changes in the view, as do real reflections.
Reflection maps look more realistic if you increase the Glossiness and Specular Level values in the Basic Parameters rollout. They are also affected by the diffuse and ambient color values. The darker the color, the stronger the mirror effect.
Even when the Amount spinner is at 100, the Reflection map is tinted by the ambient, diffuse, and specular colors.
If the material uses a shader other than Metal, the Specular color multiplies only reflection maps. The Value (in the HSV description) of the specular color affects the reflection intensity. If the specular color Value is 255, the reflection is at full intensity; if the Value is 0, the map is not visible.
To create an automatic reflection:
3ds Max opens the Material/Map Browser.
Alternatively, you can use the Slate Material Editor to wire a Reflect/Refract map node to the Reflection component.
To use a bitmap as a Reflection map:
Alternatively, you can use the Slate Material Editor to wire a Bitmap node to the Reflection component.