Banana object in a lighted room
Banana object selected
In this dialog, you can also choose various display options for showing the baked texture in shaded viewports.
After you click Render in the Render To Texture dialog, a number of things happen. (This is a typical set of events; the dialog gives you a lot of control over how texture baking actually occurs.)
Lighting map of the banana
By default, the texture type is Targa, and the element maps are placed in the \images subfolder of the folder where you installed 3ds Max.
The new textures are “flat”: In other words, they are organized according to groups of object faces.
This modifier manages the mapping of the flattened texture to faces of the object, and lets you adjust that mapping if necessary.
Flattened texture-mapping coordinates for the banana
The Shell material lets you access both materials and adjust their settings, if necessary. It also lets you choose which material to view, the original material or the texture-baked material, in shaded viewports or in renderings.
New shell material contains the banana's original material (below left) and the baked texture (below right).
Rendered light map applied to the banana
With the light map, banana appears lit even when lights are turned off.
That is texture baking in a nutshell.