Every program has a different type of object management. By object here I mean a piece of geometry that is isolated from another one. An example might be a head: The head is one object, each eye is another, the teeth will be defined as another etc. Some programs use a layer system where each object can be placed on a layer and can be isolated by turning that layer off or simply making it an un-editable wireframe.

An example of this would be Lightwave:

Others programs have a hierarchical list system where each object receives a name and can be selected from this list as needed. Usually only items that are selected/highlighted can be acted upon. Also, it is usual to find grouping and surface naming which allows for easy selection as the model becomes more complex. Using the head as an example again you may decided to group all the teeth together in a set but also give each one a different surface allowing you to select the whole set or just an individual tooth.



Regardless of the software that you choose it is imperative that you plan your modelling and think about grouping and naming parts well before you touch any geometry. Make things easy for yourself and don't become sloppy in your approach to modelling. Laziness early on in a models creation will lead to frustration for you at a later stage when you want to go back and isolate a part of the mesh.

Remember! Object and Surface management is handled differently in every 3D program: Take time to appreciate what your program can and can't do.

Basically these navigation tools help you to move around the model to help you build it in 3D. It is you/your viewpoint not the model being moved around inside the virtual workspace.

Rotate is like arcing around your model and usually depends on what you have selected.
Zoom is like you walking backward and forwards to and from your model.
Dolly/Pan is like you side stepping left or right.

Add to these such features as roll, bank, walk through, dolly up/down etc. and you will have free reign in your virtual modelling world.

Remember! Learn it and learn it well. If you can't navigate your workspace efficiently you won’t progress very quickly. Navigation shortcuts are the first shortcuts that need imprinting on your subconscious or post-it-noting to your monitor sides.

Incidental note: Not all modelling packages work on the Camera/3D virtual workspace principle. ZBrush has a fixed viewpoint (no camera at all) and the models are presented in an isometric view by default.
Lightwave has two modules (Modeller and Layout). `Modeller` doesn't have cameras as such but does allow most of the navigation described above.
Amorphium has a virtual potters wheel that keeps the model spinning for you whilst you work.

Looking from different Viewports

Once you have a good grasp of how to move around your 3D World you can start to look at it from different viewpoint and to do this you need to understand Viewports.

So far I have only described things as seen from the `Perspective viewport`. In most programs you have the option of viewing your scene from the top, bottom,front, back, left or right. You can usually have a number of viewports open at once which is commonly know as a Quad view. This can be very helpful when modeling complex meshes as you can see what is going on from a number of angles all at once.

Example of a Quad View

In and out is the Z Axis. Plus and minus in and out of the Z axis.

Most programs use a system that allows you to select an object either as a whole or by individual components.

The most common modes/component parts are:

Object (The object or model as a whole)
Polygon face (Face)
Polygon Edge (Edge)
Point or Vertices (Vert).

Each of the componants that make up an object (and the object itself) can be selected and acted upon in a number of ways most commonly:

Object/Move	Object/Scale	Object/Rotate
Face/Move	Face/Scale	Face/Rotate
Edge/Move	Edge/Scale	Edge/Rotate
Point/Move	Point/Scale	Point Rotate

Componants and Objects can be scaled as a whole or along X,Y or Z axis.

One very important thing to remember is that a Polygon `Face` can point in only one direction. The example below show two primitive shapes. The orange lines are Surface Normals which are lines protruding from the centre of a Polygon Face that can help you to see which way a polygon is facing. All of the faces on these two shapes are facing in the same direction


If I take away a few of the faces you can better understand what this means to you as a modeler. In the next image you can see where I have removed four polygon faces from the front of the Cube. Now you can see that the Faces of the Cube are transparent from the back indicating that they are facing the other way. You can still see the Surface Normals pointing outwards. This happens because I have switched on a feature called Back Face Culling (in other words `Hide the back of the Face`)



In the next image the two Cubes look very similar until you notice that the Surface Normals on the second Cube are all pointing inwards. Both of these Cubes have Back Face Culling turned off so you can see the back and the front of the Polygons Faces. However, on the second Cube I have reveresed the Surface Normals so that they face into the Cube. For a model to be accurate you need to ensure that all your Surface Normals are pointing in the right direction. There is often a feature that allows you to check this or correct it (Unify Normals or Invert Normals)

ZBrush has a powerful symmetry feature that allows you to use it's Sculpting Brushes on a model symmetrically. It also has a restore symmetry should you mess up the symmetry or import a wireframe that has lost its symmetry.

`Connect Poly Shape' is a very useful set of plugins for Maya that adds functionality to this tool.
Tools/Scripts for Max include CSPoly Tools, Meshtools, Polymagus 2.0 beta All available at www.scriptspot.com
Wings 3D has a very powerful Virtual Mirror that is recommended by a lot of modellers.
Cinema4d uses a powerful "symmetry object" which allows multiple mirrors simultaneously across all 3 axes.
Lightwave has an excellent VirtualMirror plugin available here

Some of tools available are:

Split Polygon Allows you to select an existing point or sometimes a postion along an Edge then select an adjacent Edge or point to add a new point which splits the polygon by adding a new edge.
Knife will run a split through the geometry that it crosses. very useful in Views other than the perspective view.
Split loop/Bandsaw will split polygons in half by adding a new edge down the centre. There is often some way to control Exactly where the split will occur either a slider function, graphically or numerically.
Spin Edge/Spin Quad whilst not a cutting or splitting tool is invaluable when used in conjunction with the other tools. It is used to change the flow of an Edge loop by literally spinning an Edge that falls between two faces thus altering polygon flow. incidental info: SpinQuad Forums got it's name from this little feature so it shows how important it is to some people.

As we are now aware when an object is Sub-divided it becomes visibly smoother. Smooth, Tighten or Average Vertices are smoothing commands that smooth selected Points (or Edges and Faces in some programs. This can be used to selectively refine the look of an area on a model without adding more geometry or Sub-dividing. Using Smooth and your programs Tweak mode are the best way to achieve a smooth model in its non-Sub-divided form. The Smoother and more refined you can make your Mesh the better. Of course be careful not to Smooth away the wrinkles and folds that you want to keep. You can go over the top here!

Incidental info:Most 3D Programs have a Smooth Shade option of some type. This is usually a surface attribute and as such lt is neither a Sub-division routine or a smoothing Tool that affects geometry.

ZBrush has several unique smoothing techniques including a Smoothing Brush that allows you to paint an area of mesh and see it interactively smooth. Another unique way is to use an Alpha masking tool to protect part of the model and use a Smoothing deformation Slider to do the smoothing.

One of the biggest challenges for the Polygon Sculptor is keeping within a limited polygon count. If you use tools like Split Face Loop a lot you end up with geometry around your model that simply isn't needed. There have been numerous articles and forum threads about this subject for a long time and here are some of the main ways to add detail in a local area

Quads that look like Tris: A very well known technique, A four sided polygon that looks like Triangle. This is the simply a way to keep your poly count low. Using Connect/split polygon etc. you can Split a run of Faces that lead to a Triangle. This gives you a Quad that has the look of a Triangle but Sub-divides as a Quad with no errors to worry about.


Narrowing the field: Essentially the same as the above example, the examples below show how you can reduce the amount of polygons in a set of Face loops. This does create five star poles but if placed correctly these will not create problems for you. It is a common way to allow you to have more detail in one area that is leading into an area of less density e.g. A face and forehead.


Adding creases and wrinkles: There are a great many plug-ins around these days that will do this for you. If you need Wrinkles on a forehead and only want to add local detail you need to Split the Face Loops across the top off the head and run the Loop back on itself.



Partial Sub-divide

At differing stages during a models creation you may need to move portions of the mesh around to achieve the required shape. Doing this point by point is tedious hence the need for a magnet tool also called Soft selection or Dragnet. There is often a way to adjust the falloff or influence amount allowing greater or lesser amounts of movement.