Creating a crease in a subdivision surface

Learning Resources > Tutorials > Getting Started with Maya > Subdivision Surfaces > Lesson 1: Modeling a subdivision surface >

One of the unique features of subdivision surfaces is that it’s easy to create a crease or ridge on a smooth surface. You’ll do this in the next steps.

To crease the edge of the fingernail

Switch to Edge selection mode and shift-click the edges around the nail to select them. (It might be easier to see the desired edges by first selecting Shading > Wireframe.)
After you select the edges, select Subdiv Surfaces > Full Crease Edge/Vertex.
Once you crease an edge, it displays with a dashed line as a visual reminder that the edge has been creased. If you change your mind, you can remove the crease using Subdiv Surfaces > Uncrease Edge/Vertex.
To create a ridge at the edge of the nail, switch to Vertex selection mode and select the level 2 vertices on the skin at the perimeter of the previously selected edges. Move them up so that the skin’s juncture with the nail forms a slight ridge.
Now experiment on your own by moving individual vertices to shape the nail and surrounding region as desired. A few suggestions follow:

In Smooth Shade display mode (Shading > Smooth Shade All), certain vertices might be below the shaded surface and therefore impossible to select and move. To display and select such vertices, switch to wireframe shading (Shading > Wireframe). After selecting the vertices, return to Smooth Shade display mode so you will be able to more easily see the results of moving them.
You might get better results using the Move Tool’s default World setting rather than the Normal setting made in a prior step. To return to the default setting, select Modify > Transformation Tools > Move Tool, Rotate Tool, Scale Tool, Show Manipulator Tool > . In the Tool Settings window, click Reset Tool, and then close the window.
To extend the front of the nail past the skin with a sharp edge, add a second crease on the edges below the tip of the nail. (With the appropriate edges selected, select Subdiv Surfaces > Full Crease Edge/Vertex.)
You might also want to add an additional level of vertices at the edges. (With the appropriate vertices selected, select Subdiv Surfaces > Refine Selected Components.)

After you crease the edges and add the extra vertices, you can make the nail’s edge overhang the skin below it by dragging the vertices at the nail tip out and away from the finger. Then tuck the row of vertices below the overhanging vertices in the opposite direction.

An example of a completed nail follows:

If you want more practice, repeat the procedure for the rest of the nails.
When finished, select Modify > Transformation Tools > Move Tool, Rotate Tool, Scale Tool, Show Manipulator Tool > . In the Tool Settings window, click Reset Tool, and then close the window. This returns the Move Tool to its default settings. This will avoid confusion in future lessons.