Working with Modifiers
Even though you used smooth shading in the mesh, the object still doesn’t look just right, as it has very low resolution. You could use a Subdivision Surface modifier to add more detail to the surface and smooth it out (at the cost of adding more polygons to the object). A modifier is an element you can add to an object to alter it, such as a deformation, the generation of geometry, or the reduction of existing geometry. Modifiers won’t affect the original mesh and adapt automatically to the changes you perform in the original mesh, which gives you a lot of flexibility, and you can turn modifiers on and off when you want. You should be careful, though, as adding too many modifiers may cause your Blender scene to operate slowly.
Clicking the wrench icon in the Properties Editor opens the Modifiers tab, where you can add modifiers (see Figure 3.6). When you click the Add Modifier button, a menu displays every modifier you can add to the active object. (Not all the modifiers are available for every type of object.) The modifiers are listed in columns based on their functions: Modify, Generate, Deform, or Simulate. Left-click a modifier in the list to add it to the active object.
Figure 3.6 On the Properties Editor’s Modifiers tab, you can add modifiers to the active object.
When you add a modifier, a node is added to the modifier stack, which works similarly to layers; if you keep adding modifiers, they add their effects to the previous modifiers. Keep in mind that the modifier stack works in the opposite order of layers in other software, such as Adobe Photoshop. In Blender, the last modifier you add is at the bottom of the stack, and its effect alters the effects of the modifiers above it in the list. The order of the modifiers is crucial in defining the resulting effects that the modifiers have on the object.
If you model one side of a mesh, for example, assign a Mirror modifier to generate the other half and then assign a Subdivision Surface modifier to smooth the result, the Subdivision Surface modifier should be at the bottom of the list. Otherwise, the object is smoothed before being mirrored, and you see the seam in the middle.
Adding a Subdivision Surface Modifier to Your Object
The Subdivision Surface modifier is one of the most common modifiers used in models, because it allows you to increase the details and smoothness of a low-resolution model interactively. You can change the number of subdivisions at any time to display a smoother surface. The modifier basically divides each polygon and smoothes the result. As a rule of thumb, when you apply this modifier, the number of faces in your model is multiplied by 4 for each subdivision you apply; therefore, be mindful of the polygon count when setting high subdivision values. You can use this modifier to smooth your monkey-head object, as shown in Figure 3.7.
Figure 3.7 Before and after applying a Subdivision Surface modifier
When you add a modifier, you get a panel in the modifier stack with options that are specific to the modifier you picked. Here are the main options you’ll find with a Subdivision Surface modifier:
In the top row of the panel that encloses the modifier, you can expand/collapse the modifier (by clicking the little triangle to the left), rename it (give the modifier an intuitive name when you have a lot of modifiers added to an object), and define the contexts in which this modifier should be visible. Two buttons with arrows pointing up and down allow you to change the order of the modifiers when you have more than one modifier in the stack. Clicking the X button deletes the modifier.
Next, you find two buttons: Apply and Copy. Apply transfers the effect of the modifier to the mesh itself. It deletes the modifier, but its effect on the mesh is permanent. Copy duplicates the modifier.
In the Subdivisions section are two fields that let you define the number of subdivisions that the modifier will perform in 3D View and in the render. This option is very useful because when you’re in 3D View, you usually want to save resources to ensure that this view is responsive but, in a render, you want a high-quality result. You can set a low number of subdivisions for the 3D View and a higher number for the render.