A normal map is a type of transfer map, meaning that it is a texture created from a polygon object. Different transfer maps handle the conversion from polygons to textures in different ways. A normal map captures the surface normal information of the source mesh and uses it to light the target mesh.

To set a base material for the target mesh

1. Right-click the mesh and select Assign New Material from the pop-up menu.

   The Assign New Material window appears.

   
2. In the list of materials, select Blinn.

   Maya applies a default blinn shader to the low resolution mesh.

   
3. Close the Attribute Editor.

To show the high resolution mesh

1. Open the Outliner (Window > Outliner).
2. In the Outliner, select hi_res_toad.
3. In the main menu bar, select Display > Show > Show Selection.

   Both meshes appear in the scene overlapping each other.

4. Deselect the high resolution mesh.

To create a normal map

1. Select Lighting/Shading > Transfer Maps.

   The Transfer Maps window appears.

   The Transfer Maps window lets you create various textures based on mappings from polygon models. First you need to assign the source and target meshes for the transfer.

2. In the Outliner, select lo_res_toad.
3. In the Transfer Maps window, in the Target Meshes section, click Add Selected.
4. In the Outliner, select hi_res_toad.
5. In the Transfer Maps window, in the Source Meshes section, click Add Selected.

Next you need to set the Search Envelope.

The Search Envelope represents the volume of the target geometry to consider for the texture. Whatever part of the source mesh between the Search Envelope and the target mesh is mapped to a texture.

Generally you want the Search Envelope to encompass your entire source mesh so you don’t miss any detail.

To set the Search Envelope

1. In the Transfer Maps window, in the Target Meshes section, set Display to Envelope.

   The low resolution toad is replaced by a translucent red mesh.

   This red mesh represents the Search Envelope.

2. Drag the slider under Search envelope (%) to the right.

   The red mesh grows.

3. Drag the slider so that the red mesh barely encompasses all of the high resolution mesh without leaving any white spots (excluding the eyes). You can also enter a value in the box next to the slider. In this case, a value of 4.3 yields just enough coverage around the two meshes.
   
4. Set Display back to Mesh.

Now you can set the normal map options.

To set the normal map options

1. In the Transfer Maps window, under Output Maps, click Normal.
   
2. In the Normal Map text field, click the browse icon ().

   A file browser appears.

3. Navigate to GettingStartedMaya2012LessonData\UVMapping and enter the name toad_texture.
4. Click Save.
5. Set File Format to DDS (dds).
6. Under Connect Output Maps, set Connect maps to to Assigned shader.
7. Under Maya Common Output, set Map width and Map height to 1024 and Sampling quality to Medium (4x4).
8. Click Bake and Close.

   Maya generates a normal map.

   Note

   It may take a few minutes for Maya to generate the normal map.