Normal bump mapping is a way of adding high-resolution detail to low-polygon objects. It is especially useful for real-time display devices such as game engines, and it can also be used in rendered scenes and animations.
A normals map is a three-color map, unlike the grayscale maps used for regular bump mapping. The red channel encodes the left-right axis of normal orientation, the green channel encodes the up-down axis of normal orientation, and the blue channel encodes vertical depth.
In the 3ds Max interface, controls for normal bump maps appear in three locations:
Specifically, normal projection controls are found on the Objects To Bake rollout and the Output rollout.
You can apply a Projection modifier yourself, or let Render To Texture do so automatically.
Render To Texture creates this automatically if you turn on Output Into Normal Bump (step 9, above).
If you use a Nitrous driver (Nitrous Direct3D 11 is the default) or a Legacy Direct3D driver with DirectX 9 or later, you can view normal maps in any shaded viewport.
If you use a Legacy Direct3D driver with DirectX 8, you can view normal maps in viewports by using the Metal Bump shader.
If you use the OpenGL driver, in viewports normal bump maps do not appear to be three-dimensional. However, you can still render them and use normal mapping in renderings.
You can associate different sub-object selections with different high-resolution geometry.