ARTC 312  3D Animation                 Spring 2002              Modeling a Polygonal Head

With much thanks to Walter Behrnes

 

Set Up:

We will create a tool to control the transparency of the default (lambert1) texture.

The goal is two fold, one, to allow us to control the transparency of the model we are building so we can see the image plane, and two, to give us quick and easy access to the transparency attribute.  Then we will create two reference planes to put our drawings on.

 

Creating a Control Cube.

 

1. Make a polycube rename it Control Cube and delete its history.  Edit - Delete by Type - History
2. Nav. to Windows->/General Editors->/Channel Control
3. move all the Keyable controls to Non Keyable, close channel box.

 

       

 

4. With the cube selected, notice that there are no attributes for control_cube in the channel box.  Make sure control_cube is selected in the channel box.

5. Go to Modify->/Add Attribute
6. Name = Transparency;
    Data Type = Float;
    Numeric Attribute Properties Minimum = 0 Maximum =10 Default = 0

OK

 

 

  1. Now you should see a transparency attribute in the channel box for control_cube.

 

Now we need to connect the transparency attribute to the lambert1 shader.  To do this we need to use a set driven key that is linked to the control CUBEs Transparency attribute and the transparency of the default shaders transparency.

 

8. In the Animation Menu Set, Go to Animate->/Set Driven Key->/Set (options)

9.     Select the Control Cube Load Driver = Control Cube;

10.  Select the Lambert in the HyperShade  Load Driven = lambert1.

11.  In the Driver, select transparency, in the Driven select transparencyR,G, and B

12.  Double click the Lambert1.  Click the Transparency Black square.  Change the HSV to RGB

13.  Hit the 5 key to view your scene in shaded mode.

14.  In the Set Driven Key menu, set a key with the control_cube transparency value at 0 and the lambert1 transparencyR, G, and B values at 0; then set another with the control_cube transparency value at 10 and the lambert1 transparencyR, G, and B values at 1.  Close the Set Driven Key menu.

15.  With the transparency attribute selected in the channel box, MMB-drag in a view window.  You should see the transparency of your control cube change. 

 

Because this is the default shader, it will alter the surfaces of all models you build that use the default shader.

 

Creating the Reference Plane:

 

We will use poly planes instead of image planes because they are easier to control, resize, and translate.  We can also put them in layers.

1.     Create two polyplanes, with one subdivision in both directions.  One should be oriented on X, the other on Z. 

2.     Scale your control_cube down, and place it off to the side.

 

 

 

3.     Select the 2 planes and put them in a layer.  Name the layer something like “Reference”.   Place your images on the cubes, and scale, etc. the images until the layout makes sense.  I have used alpha channels in my images to hide the background so I can concentrate on the forms.

 

Alpha Channels in Photoshop:

 

1. Select the color you want to get rid of with the magic wand

2. Open the Channels window

3. Click the Save As Selection button in the bottom of the window

 

 

 

 

 

4.     If you view the layer as “R”, then you can see the images but you cannot alter the planes.

5.     Make a polygonal cube with 1 subdivision in height, width, and depth.  Scale to fit your head reference.  Use your control_cube to make the new cube transparent.

6.     Name your polygonal cube “head”; apply smoothing to the poly using the defaults. Select “head”, and in the modeling menu set, go to Polygons->Smooth.

7.     Repeat the Polygons->Smooth.

8.     Move to a side view, and with “head” selected, go to the animation menu set, go to Deform->Create Lattice.

9.     Form the lattice to fit the profile.  When it is satisfactory, select the head poly, and delete it’s history.

10.  Repeat for the front view.

 

 

11.  Go to Display - Polygon Component - Vertices so you can see the vertices

12.   Select Display - Custom Polygon Display Option and turn Backface Culling ON

13.  Select the vertices in the vertical center of the head, in a front view, and snap them to grid in the center of the world.

 

 

14.  In the front view in component select mode, select half the faces and delete half of the face model

Edit Polygon -> Delete Vertex

 

 

15.  With the face half selected in object mode (F8), we are going to mirror and instance it.  Center the pivot point on the model by snapping it to grid, then Go to Edit->Duplicate Options.  Reset, then enter –1 for the scale value of X, and select the geometry type “instance”.  Rename it head_instance.  This will make a symmetrical mirror of the half, but since it is an instance, we only have to model the original, and the instance will inherit the changes.  We will then, when we are pretty much done, delete the instance, and duplicate again, this time as a copy, and then Merge the edges.

 

16.    Now, working with the split polys tool on the original head model, create looping edges to describe the mouth, nose, and eyes.  Work from both the front and the side views.

 

17.  Be very careful to keep your model clean.  Use the merge vertex tool frequently to merge multiple vertices that share a location in space, especially at the center of the mouth and the eyes.  Try to keep your polygonal faces 4 sided as much as possible, as 3 sided and 5+ sided faces tend to crease and render unpredictably.  Begin with the mouth and eyes, and work in a radial fashion around those centers.  Delete edges and vertices to keep your model as clean as possible.

 

                                       

 

18.  Continually Edit - Delete by Type - History and select any vertices that are in the same spot and

19.  When you are satisfied with the model, delete the instance.  Select the vertices at the border edge, and snap them to the grid to make sure they are aligned.  Snap the pivot point to 0 0 0 if it is not already.

 

20.  With the half-face model selected, go to Polygons->Mirror Geometry->Options.  Make sure that the Merge with Original Box is selected, and the appropriate Mirror direction, probably +X, is selected.  Then Mirror the geometry.  This will create a mirrored duplicate of the half-head, and merge the two into a single polygonal mesh.  You may need to clean up any extra edges at the seam.

 

Mouth

 

21.  Select the middle vertex in the mouth and pull back into the mouth.

 

 

 

Eyes:

22.  To create the eyes, we will use a poly sphere. Create a poly sphere with the default options.  Stretch the sphere out on Y to form a sort of egg shape.  Select the sphere, and duplicate it using the default options.  Name the first sphere “eyeball”, and the second “cornea”.

 

23.  Select the vertices at the “pole” end of “eyeball”, and push them in on Y. You may need to hide the geometry you are not working on (Display - Hide - Hide Selection)

 

24.  Select “cornea”, and delete all the faces below the edge where you pushed in the vertices on “eyeball”, to form a lense.

 

     

 

25.  You could now apply a transparent Phong shader to the cornea, and texture the eyeball.

 

26.  Delete the faces in your head model where the eyes would be, and scale and place the eyeballs in the head.  You may need to add more concentric circles around the eyes to add detail and form eyelids, and extrude the edges at the opening of the eye to give thickness to the eyelids.