[N-World Contents] [Book Contents] [Prev] [Next] [Index]

Reinstance, Copy, & Multiply

This chapter describes the difference between three techniques that can be used to "duplicate" an object in N-Geometry: Reinstance, Copy, and Multiply. You'll also learn how to create various types of lattices using the Multiply command.

New Techniques in this Chapter

This chapter describes the difference between several commands that are used to "duplicate" objects in N-Geometry:

Reinstance

Copy

Multiply

Each of these techniques can be used in different contexts in N-Geometry.

Reinstanced Objects

When you reinstance an object, N-Geometry creates a new object that shares the body of the original polyhedron. Any change made to the body is shared by any reinstance that shares that body.

If you modify any instance of the body, all instances reflect that change.

If you modify objects, any reinstance can be changed independently (since changes are made to the object, not the body).

Try this:

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

A cube appears in the N-Geometry window.

Figure 17.1 A default cube

2. (CLICK-R) on Copy.

A menu of copy options appears.

3. (CLICK-L) on Reinstance>Cube.

Nothing appears to happen; however, you have reinstanced the cube. The reinstance is currently in the same position as the original.

4. (CLICK-L) on objects in the elements sensitivity menu.

5. (SHIFT-L) on the reinstanced cube, then (CLICK-L) on Axis Move>X.

Remember that the name of the selected object appears in the upper left corner of the N-Geometry window. Move the reinstanced cube along the positive X axis (to the right).

Figure 17.2 A reinstanced cube

6. (CLICK-L) on points on the element sensitivity menu.

7. then (SHIFT-L) on a corner of the original cube, then (CLICK-L) on Move.

As you move the mouse around, the vertex on the original and the corresponding vertex on the reinstanced cube move in unison (with relation to their local space).

Figure 17.3 Reinstanced objects inherit modifications performed on the original

Now try the same thing, this time choosing a vertex on the reinstanced object-the original object is updated as well. Again, this is because reinstanced objects share the same body.

: Note. Any modification that you perform on the body of a reinstanced object affects all other reinstances of that object.
: Note. Reinstancing objects takes considerably less memory than copying; you may want to consider this when working with very complex objects.

Copied Objects

When you copy an object, you create a single discrete new object in the same location as the original. The duplicate is named "Copy of Object" where "Object" is the name of the original.

Try this:

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

A cube appears in the N-Geometry window:

Figure 17.4 A cube

2. (SHIFT-L) on objects on the element sensitivity menu.

3. (SHIFT-L) on the cube, then (CLICK-L) on Copy.

Nothing appears to happen; however, you have copied the cube. The copy is currently in the same position as the original.

4. (SHIFT-L) on the cube, then (CLICK-L) on Axis Move>X.

Move the copy of the original cube along the positive X axis (to the right).

Figure 17.5 A copied cube

5. (CLICK-L) on points on the element sensitivity menu.

6. (SHIFT-L) on a corner of the copied cube, then (CLICK-L) on Move.

As you move the mouse around, the vertex on the copy moves; however, the original is unaffected:

Figure 17.6 Copied objects have completely unique bodies and bdi's

Now try the same thing, this time choosing a vertex on the original object-the copy is unaffected. This is because copied objects are completely discrete-that is, they have individual bodies, as if they were both created from scratch.

Multiplied Objects

Finally, you can create multiple copies or instances of an object, in various patterns, using the Multiply command.

Try this:

1. Create a simple object, such as a cube.

Figure 17.7 A cube

2. (CLICK-R) on Copy.

A menu of copy options appears.

3. (CLICK-L) on Multiply>Cube.

The Choose Multiple Copy Parameters dialog box appears. By specifying different parameters in the dialog box, you can create different patterns of either copied or reinstanced versions of a selected object.

8. (SHIFT-L) on a segment like the one shown in Figure 17.21, then (CLICK-L) on Dissolve.

Figure 17.21 Dissolve extra segments

The segment is dissolved, leaving one segment along the length of the merged region (the new face):

Figure 17.22 After dissolving the extra segment

9. Dissolve the similar segment on the other side of the base.

10. (CLICK-L) on one of the segments at the base, then (CLICK-M) on Axis Move>Z.

Figure 17.23 Giving the tree some depth

11. Axis Move the corresponding segment on the other side of the tree base.

When you're done, you should have a tree trunk that looks something like this:

Figure 17.24 Finished tree trunk

Creating the Bounding Object

This part is simple; think of the bounding object as a volume along whose vertices you want the multiplied copies of the object to appear.

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

13. (CLICK-R) on Sphere.

Change the following parameters on the menu that appears:

enter 8 for n-Latitudes
enter 8 for n-Longitudes

Figure 17.25 Sphere parameters

14. (CLICK-L) on the Make Sphere button.

This creates a sphere divided eight times horizontally and vertically:

Figure 17.26 Sphere

15. (SHIFT-L) on the Sphere, then (CLICK-L) on Move.

Move the sphere so that it's centered around the end of one of the branches.

Figure 17.27 Moved sphere

In this case, the sphere defines the basic area in which leaves will be multiplied. You can scale modify the topology of the object if you want to create a more irregular shape for the distribution of the leaves, or change the number of points on the bounding object.

Creating the Object to be Multiplied

Now we need to create the leaf. Use GeoMenus>File>New Object>Lamina, make a leaf-shaped lamina. Don't worry about the scale of the leaf; we'll modify that appropriately when we return to the N-Geometry window.

Figure 17.28 Create a leaf-shaped lamina

If you use any bezier wires (curved segments) in creating the lamina, the following menu appears:

Figure 17.29 Bezier samples for generated lamina

Use the default number of segments (11) and (CLICK-L) on Make Lamina.

Figure 17.30 The generated leaf

16. If you need to, (SHIFT-L) on the leaf, then (CLICK-L) on Scale to scale it to the appropriate size:

Figure 17.31 Scaled leaf

17. (SHIFT-L) on the leaf, then (CLICK-R) on Position>Origin.

This puts the leaf at the global center.

Figure 17.32 Repositioned leaf

You're now ready to make your lattice.

Making the Lattice

18. (CLICK-R) on GeoMenus>Copy.

19. (CLICK-L) on Multiply.

Enter the following parameters:

(CLICK-L) on Object to Multiply and select the leaf object.
Set Duplicate How to Reinstance-Copy
(CLICK-L) on Arrangement Mode and select Per Point.
(CLICK-L) on Points Source and select the sphere object.
Set Align? to Random
Set Randomize to No

After you've selected these parameters, (CLICK-L) on the Make Multiple Copies button.
Reinstanced copies of leaves appear at each point on the sphere, with their normals aligned randomly:

Figure 17.33 Reinstanced leaf

The reinstanced leaves are structured under a top level object. If your objects were called "leaf" and "sphere," the generated top level object is called "leafs on sphere."

20. Make the sphere invisible.

21. Turn Shading on for both the new lattice and the trunk.

Figure 17.34 Shaded tree

You can create new bounding objects, using normal or magnet moves to create free-form shapes. Just remember that an object is generated at each point along the bounding object.

Figure 17.35 New bounding object, and generated lattice

Aligning Objects on Points of the Bounding Object

In the example above, used a random alignment of leaves on the points of the bounding object; there are several options for aligning the multiplied object on the bounding object:

Figure 17.36 Alignment options (No, Normals, Random, Radial)

Using Randomize with Per Point

You can use the Randomize feature of the Multiply command to distribute the reinstanced or copied objects around the points of the bounding object.

Combining Subobjects

If you are working with a game platform, and you want to make all the subobjects into one single top level object:

22. Collect all the leaves (or objects) that you want to combine.

You might, for example, make all the objects in the scene invisible except for those you want to combine, then use the 3D lasso to collect the objects.

: Note. Objects created with the Multiply command are added to the scene with their sensitivity turned off (gray). You must make an object sensitive to select it through the N-Geometry window. Refer to the N-Geometry Reference Guide for directions on toggling the sensitivity of an object.

23. (SHIFT-L) on the collection, then (CLICK-L) on combine.

24. Give the new object a name when prompted, then (CLICK-L) on the Rename button.

: Note. If you combine many subobjects into a single top-level object, then delete the subobjects, you should see better response when moving the camera in the N-Geometry window. This is because there are fewer objects for N-Geometry to keep track of during the move.

Save your Work

Make sure to use the GeoMenus>File>Save operation to save your work.

Congratulations!

You've now learned:

the difference between reinstancing and copying objects

how to create normal and randomized lattices (including leaves on a tree!) using N-Geometry's Multiply command

[N-World Contents] [Book Contents] [Prev] [Next] [Index]

Another fine product from Nichimen documentation!

Reinstance, Copy, & Multiply

Multiplied Objects

Making a Linear Lattice of Objects