VFXWorld presents the first installment of a new series of excerpts from Building Interactive Worlds in 3D by Jean-Marc Gauthier. This month we present a tutorial in modeling from the Basic 3D Kit.
All images from Building Interactive Worlds in 3D: Virtual Sets and Pre-Visualization for Games, Film & the Web by Jean-Marc Gauthier. Reprinted with permission.
This is the first of 12 excerpts from Building Interactive Worlds in 3D by Jean-Marc Gauthier. For the next few months, we will be present chapters from a section entitled The Basic 3D Kit.
Start your project by creating a project folder and its subfolders, where your content will be saved.
To Generate a New Project Folder
Go to the top menu, select, File > Project > New. In the dialog window specify a name for your project, choose the location where it will be saved, and click on Use Defaults. Click Accept to close the window.
To start creating the character, choose the modeling module. Go to the top menu, and select Create > Subdiv Primitives > Sphere.
Subdivision Surfaces has two modes: the PolygonProxy Mode, in which the shape can be manipulated as a polygonal mesh, and the Standard Mode, used for fine details.
We will use the PolygonProxy Mode for this tutorial.
Go to the top menu, and select Subdiv Surfaces > PolygonProxy Mode. The workspace displays a wireframe cube with its smooth approximation.
Press key 5 to display the sphere in the shaded mode.
Press key 3 to increase its smoothness.
Now lets select the cube by its components: vertex, line, and polygon.
In the Status Line, click on the Select by Components button, then click on the Face button. The color of the cube changes to blue and a handle appears on each of the sides. Lines of bounding boxes are visible on the borders of the polygons.
To select the left side of the cube, click on the blue handle located on the left side of the cube. Press the Delete key. The 3D object looks like one-half of a sphere.
You can subdivide the polygons of the cube by selecting the Object Mode from the Status Line or by pressing the F8 key. The edges of the polygons turn green.
Go to Edit Polygons > Subdivide > Options. The Polygon Subdivide Face Options dialog window contains options for the Subdivide tools. Select subdivision level = 2 and click on Subdivide. Your model is similar to the one in the following illustration. First, you will be modeling only one side of the character. Later, you will mirror the other side of the 3D model.
This soft cube represents one half of the characters torso. You can use Move and Scale from the Tool bar to reshape the torso.
Go to the top menu bar, select, Polygon > Tools Options. Ensure Keep Faces Together is turned on.
In the Status Line, choose the Components Face mode. You can also press the F11 key. Select two polygons located on the right side.
Go to the top menu, and select Edit Polygon > Extrude Face.
You just created a new polygon that remains connected with the rest of the character. The Manipulator tool is automatically activated. Click and drag the yellow arrow, perpendicular to the selected polygons. You will notice that the smooth surface is changing shape locally. You began to create a new arm for your Cyclop.
Repeat the same operations for the left leg and the neck.
Lets play with selecting other components such as lines and vertices. You can select lines and vertices either from the icons of the Status Line or by pressing the F10 or F11 keys.
Lets model the characters limbs and face from the basic shape that you created.
Lets work inside the model to define the mouth and the eye socket.
Go to the top menu, and select Edit Polygons > Extrude Face. Select the Extrude Face tool or the Split Polygon tool to add more details.
To split a polygon, select Edit Polygons > Split Polygon Tool. Select the Split Polygon tool, and click and drag on the desired lines surrounding the polygon. This tool will let you create small details such as the eyes, the nose, and the fingers.
To create the fingers, select the polygon located on the edge of the hand. Split the polygon into five polygons in the area that will become the base of the fingers. Three fingers will be extruded from five polygons.
To finish the detail of the fingertip, go to the top menu and select Edit Polygons > Poke Faces. Move the vertex located in the middle of the polygon at the fingertip to add a nice finishing touch to the fingertips.
Repeat the same operation to create the thumb. Select the polygon on the side of the hand. Use the Extrude Face tool, move the new polygon, extrude again and poke the face. Move the vertex located in the middle of the polygon at the fingertip to get a nice finish of the thumb.
The same operations can be repeated for the leg and the toes.
Once you enjoy the look and feel of half of the characters body, you can convert the 3D model to a polygonal mesh.
To Convert to a Polygonal Mesh
Go to the top menu bar, select Modify > Convert and check on the Subdiv to Polygons option box. The box is on the right of the name of the tool. A dialog window will open. Select the Tessellation Method with Uniform.
The Adaptive Method option may increase the tessellation inside the detailed area, which would create too many polygons. We will choose the Uniform Method because we want to keep down the number of polygons. Enter the following settings: Level = 1, the Division Per Face = 1, Replace Original Object = ON.
After conversion, you should have a shape made of interconnected polygons similar to the one you had before. Lets repeat the same modeling steps to add on more details for ears, nostrils and wrinkles on the polygonal mesh.
Lets model the teeth.
Select the edges on the lips polygon located inside the mouth. Go to the top menu, select, Edit Polygons > Extrude Edge. Move the newly created edges.
Because your modeling job is detailed enough, you are going to duplicate the other half of the body to create a whole character.
Modeling of the eye.
To Create the Other Half of the Character
Go to the top menu, select Edit > Duplicate Options.
In the dialog window, go to the column for the X-axis, and change the scale value = -1. Click the Duplicate button. A complete mirrored clone is created. The edges of the two halves should slightly touch each other. If this is not the case, use the move tool to adjust one half.
To Combine the Two Halves
Go to the top menu, select Polygons > Combine.
The color of the meshes changes from green and white to green, indicating that we have one surface.
The edges need to be welded together.
To Weld the Edges Together
Select the edges of each of the halves by clicking on one edge on the left half and on one edge on the right side.
Go to the top menu, select Edit Polygons > Selection > Select Contiguous Edges. Both edges will have a brown color.
The next step is merging two surfaces into one continuous surface. Go to the top menu, select Edit Polygons > Merge Multiple Edges.
Accidents on the surface of the mesh can be hard to detect. Gaps and holes can prevent some edges from being welded together.
To Detect Holes on the Surface of the Mesh
Go to the top menu and select Display > Polygon Components > Border Edges. Maya displays a thicker line around the contours of holes appearing in the mesh. In this example, the edges surrounding the mouth and the eye are obviously needed for our Cyclop character.
To Close Unwanted Holes and Gaps
Go to the top menu and select Edit Polygon > Merge Edge. Click on the first edge of the hole and on the corresponding edge on the other side. Press Enter, and repeat the same process until the surface is closed.
Lets model the eye.
Go to the top menu, select Create > Polygon Primitives > Sphere. In the dialog window, specify the number of subdivisions along the height and around the Y-axis = 10. Select Create.
Save your scene. Go to top menu, and select File > Save Scene As.
Find more turnkey tutorials that detail all the steps required to build simulations and interactions in Building Interactive Worlds in 3D: Virtual Sets and Pre-Visualization for Games, Film & the Web by Jean-Marc Gauthier: Focal Press, 2005. 422 pages with illustrations. ISBN 0-240-80622-0 ($49.95). Check back with VFXWorld frequently to read new excerpts.
Jean-Marc Gauthier teaches at New York University in the graduate studies department of Interactive Telecommunications and is the author of Interactive 3D Actors and Their Worlds (Morgan Kaufmann Publishers 2000). He is also a consultant at www.tinkering.net and an award-winning 3D artist.
