The second tip is very quick and simple, but it's extremely useful when you want no seam between 2 connecting parts. Let's see how.

We will consider the neck connecting to the frontal skin which is attached to the tortoise-shell.

After you created the color, specular and diffuse maps, you have to add the Trasparency map, too. The good thing is that for this map you can use a Ramp and you don't need to convert it and do all the huge work you did for the other texture maps. So, double click on the head shader of your turtle and hit the icon just after Trasparency. In the Create Render Node window hit the Textures tab and choose Ramp:



Fig. 25

In the Attribute Editor delete one of the 3 default colors (simply hit the square on the right) and change the others to black and white (this is because Maya, and all the other 3D softwares, uses this 2 colors in the trasparency channel to show or hide the shader); change the value of the 2 colors untill the border of the turtle head connecting to the neck disappears. To change the color values click on the white or black circles on the right and move them up or down:



Fig. 26

After some attempts the result should be similar to what you see below:



Fig. 27



Fig. 28

Now we will see how to create different texture maps (for the Diffuse, Bump and Specular color) and how they affect the quality of the shader.

The first is the Bump map.

As you probably noticed, every surface in real world (even the smoothest) is irregular. For this reason this map is extremely important and lets you "draw" instead of modelling. See below:



Fig. 29



Fig. 30

As you can see above, using a Bump map you don't need to model complex patterns. These images are very simple, but you use the same "tecnique" to simulate the most complex surfaces (the folds of the skin, the cracks in the walls, ecc�). As you surely know, the Bump map looses its effects along the borders of the object (fig. 29), so pay attention whith your camera or use a Displacement map which really modify the object geometry (fig. 30).

(Tip: if you use an Environment texture, such as Env sky, as color map for the Reflected color, Maya will not calculate it correctly if there is a Bump map, too. The result is what you see in the image below:



Fig. 31

As you can see, the arrow indicates how the Reflected color (blu) isn't calculated on the relief. To solve the problem just connect the Out Normal of the bump node to the Normal Camera of the Environment texture. To do this:

Window > General Editors > Connection Editor�

Open the Multilister and click the arrows of your shader untill you see the bump2d icon:



Fig. 32

Now, drag the bump2d icon to the Left side of the Connection Editor and the EnvSky icon on the Right side:



Fig. 33

Render the scene and note the difference:



Fig. 34

This and many other interesting tricks can be found in the/art/of/maya, Alias/Wavefront.