Unmodeling

We called this chapter "Unmodeling" because it shows some techniques that you might not think of if you're used to working with other modelers. Get ready to bend your mind!

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The Hollow Cube

1. (CLICK-L) on GeoMenus>File>New Object>Cube.

2. (SHIFT-L) on the cube, then (CLICK-R) on Select Elements.

This selects all of the faces on the body of the tetrahedron.

Enter a value of 1.

4. (SHIFT-L) on the still collected faces, then (CLICK-L) on Extrude.

Extrude the faces inward slightly, but make sure they don't overlap.

5. (CLICK-L) on GeoMenus>Object Display>Shading>Cube.

6. (SHIFT-L) on one of the large faces, then (CLICK-L) on Bridge.

7. Move the camera and (CLICK-L) on the opposite face.

Your object should look like this:

Remember, however, that we now have a winged-edge model; we can't simply bridge from side to side, but must bridge the remaining faces individually.

Your object should look like this:

9. Repeate the Bridge command for each of the remaining three faces.

Your finished object should look like this:

Now, this looks pretty good, but we still have a little cleanup to do on the inside of the cube.

10. Turn shading for the object off.

11. Zoom the camera into the inside of the cube.

Look at one of the joints.

Figure 19.6 Dissolving extra segments

13. (SHIFT-L) on the segment, then (CLICK-L) on Dissolve.

Figure 19.7 Dissolving extra segments

14. Cut the face created when the segment is dissolved as shown:

Figure 19.8 Cut the resulting face

15. (SHIFT-L) on the small triangular face.

Figure 19.9 Select the triangular face

16. (CLICK-L) on Collapse.

The triangular face collapses to a point, resulting in a clean, smooth joint:

17. Repeat the cleanup process described in steps 13 through 16 for each of the remaining joints.

Your object should look like this when completed:

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The Hollow Pyramid

1. (CLICK-L) on GeoMenus>File>New Object>Tetrahedron.

2. (SHIFT-L) on the tetrahedron, then (CLICK-R) on Select Elements.

This selects all of the faces on the body of the tetrahedron.

Enter a value of .5.

4. (SHIFT-L) on the still collected faces, then (CLICK-L) on Extrude.

Extrude the faces inward slightly, but make sure they don't overlap.

5. (CLICK-L) on GeoMenus>Object Display>Shading>Tetrahedron.

6. (SHIFT-L) on one of the large triangular faces, then (CLICK-L) on Bridge.

7. Move the camera and (CLICK-L) on a second triangular face.

Your object should look like this:

8. On the remaining two sides of the pyramid, use the Bridge operation to bridge between the two faces on each side.

Your object should look like this:

Now, this looks pretty good, but we still have a little cleanup to do on the inside of the pyramid.

9. Turn shading for the object off.

10. Zoom the camera into the inside of the pyramid.

Look at one of the joints.

Figure 19.5 Cutting the inside faces

Figure 19.6 Collapse the small triangular faces

12. Repeat this modification on the inside of each joint on the pyramid.

You should have a single vertex at the inside of each joint when you're finished:

1. (CLICK-L) on GeoMenus>File>New Object>Cube.

2. (SHIFT-L) on the front face, then (CLICK-L) on Axis Move.

Choose the Z axis from the menu that appears, and move the face back so the cube has the basic correct dimensions of a dresser:

3. Collect the segments on both sides of the front face.

Figure 19.9 Collect segments on each side of the front face

4. (SHIFT-L) on the collection, then (CLICK-M) on Cut.

This cuts the segments into thirds.

Specify an Inset Width of 1 in the dialog box that appears.

6. (SHIFT-L) on the front face, then (CLICK-L) on Extrude.

Move the front face back along the Z axis so that it's almost touching the back of the cube:

Notice that because we cut the segments on the inset face that two segments run from the front of the dresser to the back.

7. (SHIFT-L) on the inset face, then (CLICK-L) on Cut.

Cut the inset face as shown below; you'll actually have to repeat the Cut operation to make both cuts.

Now that we've cut the inside of the dresser appropriately, we can make our shelves.

8. Collect the six segments on the inside of the dresser where the shelves should be.

Figure 19.13 Collect the segments which will form the shelves

9. (SHIFT-L) on the collection, then (CLICK-L) on Bevel.

Enter a bevel width of .5, then (CLICK-L) on the Bevel button. The selected segments are replaced by faces:

10. Collect the four segments in the back corners of where the shelves should be, then (CLICK-L) on Dissolve.

Figure 19.15 Dissolve the edges shown

11. Select faces on the element sensitivity menu, then (CLICK-L) on one of the "shelf" faces.

One of the advantages of N-Geometry's winged-edge object design is that you can have some quite unusual faces. In this case, two faces wrap all the way around the inside of the object.

12. Cut the face from top front vertex to top front vertex.

Figure 19.17 Choose one of the "shelf" faces

The resulting object now looks like this:

13. Cut the face again, this time choosing the two vertices directly below those shown in Figure 19.17.

Figure 19.19 The generated shelf

14. Now, cut the face for the bottom shelf in the same way.

Your object should look like this:

Building the Drawers

15. Collect the three faces at the back of the drawer "slots."

Figure 19.21 Starting the drawers

16. (SHIFT-L) on the collection, then (CLICK-R) on Chip Off.

Figure 19.22 Naming the chipped off group of faces

Give the chipped off group of faces a name, then (CLICK-L) on Add Object. The dialog box closes and the group of 3 faces is created; (CLICK-R) on the N-Geometry window to leave the faces where they are.

Pull the faces out toward the front of the dresser, until they're flush with the front.

18. Collect the faces on the top of each drawer.

Figure 19.24 Collect the faces on top of the drawers]

19. (SHIFT-L) on the collection, then (CLICK-L) on Inset.

Specify an Inset Width of .5, then (CLICK-L) on Inset.

20. (SHIFT-L) on the collection, then (CLICK-L) on Axis Move.

Move the inset faces straight down into the drawers to hollow them out:

21. Turn on Shading for the objects (both the dresser and the drawers).

If your drawers are lined up exactly with the front of the dresser, you'll see a grey cube. However, because each drawer was created from a separate chipped off face, each is a separate object and can be modified (or animated in N-Dynamics) independently.

Move the drawer forward along the Z axis.

Move the other drawers in the same way; try shading the object to see what the final will look like:

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Roman Bath

1. (CLICK-L) on GeoMenus>File>New Object>Solid of Rotation.

Use the menu defaults and sketch a contour that looks something like the one in Figure 19.8. This contour will define the contour of a repeating column, so you might want to make it a little more ornate.

Just make sure that the top of the column is narrower than the bottom:

2. (CLICK-R) when you're finished sketching the contour and (CLICK-L) on OK.

The following dialog box appears:

3. Change the number of n-Longitudes to 4 and (CLICK-L) on Make Solid to create the column:

Figure 19.31 A basic column

4. Collect the faces on the bottom of the column, then (CLICK-L) on Merge Region.

Now, when we use the Mirror operation, the bottom of the floor will remain a single face. (Of course, we could select all the faces on the bottom of the completed room, but this will save us a few mouse clicks!)

Mirroring the Column

6. (CLICK-L) on a face at the base of the column.

Figure 19.33 Mirror around a face at the base of the column

The resulting object should look like this:

Figure 19.34 Mirrored object

7. Select the column body again, then (CLICK-L) on Mirror.

8. This time, (CLICK-L) on the longer face on the newly mirrored object.

Figure 19.35 Mirror the object around the long face

Now repeat the Mirror operation twice more so that you have sixteen columns.

Figure 19.36 Sixteen columns

Building the Roof

9. (SHIFT-L) on the face on the bottom face of the object.

Figure 19.37 Select the face on the bottom of the object

10. (CLICK-L) on Flatten>Y.

N-Geometry goes into point selection mode; (CLICK-L) on one of the points on the top of the column, and the floor is "pulled up" to the height of the ceiling.

11. (CLICK-L) on GeoMenus>Shading and pick the object from the object list that appears.

That's it! The resulting environment is a single object, with no holes, all pulled out from a geometry primitive in just a few steps.

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Round Pegs in Square Faces

1. (CLICK-L) on GeoMenus>File>New Object>Cube.

2. (SHIFT-L) on the top face, then (CLICK-L) on Inset.

Use an Inset Width of 3 in the dialog box that appears.

3. Collect the segments on the inset face:

Figure 19.41 Collect the segments on the inset face

4. (SHIFT-L) on the collection, then (CLICK-M) on Cut.

This cuts the selected segments into thirds.

Figure 19.42 Select the inset face

6. (CLICK-L) on Sphericize>This Element's Midpoint.

N-Geometry goes into point-select mode.

The point you choose in this step determines the "radius" for the sphericizing operation; choosing a corner point on the inset face will make a larger circular face than if you choose a point on the center of an edge on the inset face.

Use a value between 0 and 1 to specify the rounding factor.

The face is rounded:

The degree of roundness is also affected by the number of vertices on the element being sphericized. The sphericize operation actually moves all the vertices on the selected object an equal distance from an arbitrary specified center; if you try to sphericize the face before cutting the edges, you'd see no change, since each corner point is already equidistant from the element center (which we selected as our center).

The face can now be extruded to pull a round peg out of our square cube:

9. (CLICK-L) on GeoMenus>Object Display>Shading, then (CLICK-L) on the object from the object list that appears.

The final, shaded object should look like this:

Copyright © 1996, Nichimen Graphics Corporation. All rights reserved.