Home > SCM Tutorials > Facial Features

Inserting Facial Features with SCM.
By Jeremy Birn

To add facial features to a head, you simply need to cut the closed round features into four quarters, and zip them into the head surface, using the same basic process described in the previous tutorial.

This figure shows the scene scm-tuteyes from your sample database. You could try constructing a model like this based only on your experience from the last tutorial, or for more practice, do the following tutorial, which uses the same basic steps and pattern.

SurfaceContinuityManager+ allows detailed eyes to be constructed without trims or blends, in a way that is still easy to animate and does not increase the polygon-count of the surface as high as a trimming approach.

1. In the Front view, draw a NURBS curve in the shape of a person's eye.

2. Make several duplicates of the curve, each scaled larger than the last, edit them as desired, and Surface>Skin them to create an eye surface. Delete the original curves. NOTE: The amount of time spent on high-quality modeling here is not important to this tutorial you will still be able to stitch together the eye whether the shape is completely realistic or not.

Skin a roughly eye-shaped surface.

3. Get a Primitive Grid, choose Cubic NURBS, with the default X and Z Cell Size of 1, and X and Z Cell Count of 10. Rotate the grid to 90 degrees in X, so that it appears around the eye in the Front view.

4. Draw>Cut the Grid repeatedly: First cut it at the locations of 3 and 7 in the U direction, then cut the three sections you have created at locations 3 and 7 in the V direction. NOTE: Be sure to check your Schematic view and delete the extra, overlapping surfaces that are left behind by each Cut operation.

5. Delete the center of the 9 grid sections, so that it leaves a square opening for the eye. Scale the eye if needed so that it does not overlap with the remaining sections of the grid.

The eye should fit in the middle of the array of cut grid surfaces.

5. Draw>Cut the eye into 4 sections, with cut-lines pointing towards the four corners of the square. Delete the overlapping parts in the schematic view.

6. The edges of the grid surface around the eye should each have 7 control points. If needed, use Edit>Add Point and/or Edit>Delete Point on the top, bottom, left, and right eye sections, to make sure that the point-count matches the 7 corresponding edge points on the grid sections they face.

NOTE: If you add or delete any points, use the function Effect>Reparamerization afterwards, and set all of the surfaces back to a uniform parameterization.

7. Turn on Show > Edge Flags. To make the edge flags more visible, turn off Show>Lines to get rid of the blue edges. When selected individually, each grid section should be red on the left, and green on the bottom. Select the top, bottom, left, and right sections of the eye, and make sure that they are also red on the left, and green on the bottom. For any sections that need the edge flags moved, use Effect>Curve Controls, and click Inverse U, Inverse V, or Swap UV, as needed to put the red on the left, green on the bottom.

8. Multi-select the top section of the eye, and the (top-center) grid section immediately above it. Select Draw>Zip Surfaces. Click first in the lower-left corner of the grid surface, and confirm that you want to select the row in U. Click in the upper-left corner of the eye section, and confirm again that you want to select the row in U. As with the last tutorial, slide the lower slider of the Zip Surfaces dialog box to bring all of the points up.

9. Repeat step 8 for the 3 other sections of the eye. Save your scene, then multi-select all 12 surfaces, and choose Deformation > SurfaceContinuityManager+.

10. With SurfaceContinuityManager+ active, you can tag and translate points in Z, for the purpose of making your flat surfaces into a three-dimensional model. SurfaceContinuityManager+ will hold the surfaces together as though they were one surface.

11. Select all of the surfaces, make sure you are back in OBJ transformation mode, and select Duplicate>Immediate. You have just made a copy of your surfaces, that will remain seamless without the effect being linked to them.

NOTE: Duplicating your models is a good way to "freeze" the results of SurfaceContinuityManager+, instead of losing continuity by deleting the effect. You can delete the original set of surfaces, and just keep the copy.

12. Translate the new models by -5 in X, and use Effect>Symmetry over the YZ plane to make a second eye. With all surfaces selected, apply SurfaceContinuityManager+ again.

For making overall changes to a multi-surface structure, proportional modeling will not extend its radius of influence over all of the surfaces. Without using proportional modeling, another tool available to sculpt this model into a more final shape is Lattice Deformation.


A branch-lattice may be useful for editing SurfaceContinuityManager+ models.

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This tutorial copyright © 1999 by Jeremy Birn.
Please do not duplicate any part fo this tutorial without written permission.