Deeper contains the tools to build and display normal map within Carrara.
1. Normal map definition
A normal map is a map that encodes the X, Y and Z normal information into the RGB channels of a texture map. This map is then used to create a highly detailed and fast rendering bump mapping.
A regular bump mapping use a grayscale image as a height field. But computing a normal from a height field can’t be done with a single pixel. To know the orientation of a normal on a point, several samples (at least 3) has to be taken around to determine what the slope is at a particular pixel.
A normal map directly gives the normal orientation from its RGB values, so there’s no need to over-sample the map around the pixel. The bump is through at least 3 times faster to compute than a regular bump map. More information on normal map can be found online here.
2. Uses of a normal map
A normal map can replace any regular bump map using a texture. The rendering of the bump will then be at least 3 times faster, and the bump will keep all its details whatever the rendering engine is.
Learn how to build and use a similar normal map in this tutorial.
A normal map is also a way to add volume information to a basic geometry. For example, a 2D billboard can interact with lighting and create its self shadow when a normal map is added to it.
See how to make this tree billboard in this tutorial.
3. The Normal Map Shader and Renderer
The normal map data can be read by Carrara with the Normal Map shader. To read a normal map, set the Normal Map shader in the bump channel, and then load the texture as a child of the shader. Normal map can be found on the net, or created with existing software and plug-ins. Deeper provides a way to create normal map within Carrara: to build the map, simply choose the Normal Map renderer in the rendering room, and click the render button.