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

Fantasy Tree

Plants are another type of organic object that pop up in lots of scenes. This chapter describes a technique for creating a fantasy tree.

In this Chapter

You'll learn how to build a fantasy tree using some new techniques:

Creating a solid of rotation

Multiple Extrude (repeating the operation on multiple
collections on the same object to create a "layered" effect)

Sketching a bezier wire

Changing the sampling of a wire

Collapsing nodes to change the topology of a region

In Chapter 17, "Reinstance, Copy, & Multiply" we'll describe another technique for creating a tree with hundreds or thousands of leaves.

A Fantasy Tree

Another way to create a tree is to start with a simple solid of rotation. A solid of rotation is made by sweeping a contour wire around an arbitrary axis and generating a solid shape from the "swept" area.

In this section, we'll build a contour wire, make a solid of rotation from that wire, change sampling on the wire, then finish up our tree.

Try this:

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

Each of the parameters on this menu is described in detail in the N-Geometry Reference Guide. For now, use the default parameters.

Figure 14.1 Sketch parameters

2. (CLICK-L) on the Set Sketch Params button.

The Sketch Editor opens in the N-Geometry window. The target shape for the wire is shown in Figure 14.2:

Figure 14.2 The finished wire-refer back to this figure if necessary

3. To start the wire, move the cursor straight up the Y axis.

4. (CTRL-L) to place a control point right on the Y axis.

5. Move the cursor down and to the right, then (CTRL-L) again.

This inserts the second control point.

Figure 14.3 Adding a control point

6. Move the cursor straight down, and use (CTRL-L) to insert a third control point.

As you move the cursor down, the top segment begins to curve.

Figure 14.4 Adding another control point

7. Move the cursor back toward the Y axis, then (CLICK-L) in the position shown below:

Figure 14.5 Adding a regular node

8. Now, move the cursor straight down and (CTRL-L) to insert another control point.

Figure 14.6 Adding a regular node

9. Now, let's build the tree trunk.

(CTRL-L) to add another control point in the location shown in Figure 14.7:

Figure 14.7 Adding another control point

10. Now, (CLICK-L) to add the final node on the wire, just about even with the X axis.

Figure 14.8 Add the final node on the wire

11. (CLICK-R) after you've drawn the final node on the wire.

The following menu appears:

Figure 14.9 Ending your sketching session

12. (CLICK-L) on OK, Wire too.

This option saves the sketched wire used to create the solid of rotation.
If you decide that the solid of rotation created doesn't look quite right, you can change the shape or sampling of the wire, then rebuild the solid of rotation.

13. In the Solid of Rotation parameters, change the following parameters:

Change the Object Name to fantasy-tree.
Make sure the Sketch Axis is set to Y.
Set the number of n-Longitudes to 12.

Figure 14.10 Solid of rotation parameters

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

Your solid of rotation should appear:

Figure 14.11 Completed solid of rotation

Lowering Polygon Count for the Tree

This tree is fine if you have an unlimited number of faces for your object, but if polygon count is a consideration, you need to change the sampling of the wire:

15. (CLICK-L) on segments on the element sensitivity menu.

16. Turn on Visibility for the fantasy-tree-wire.

17. (SHIFT-L) on the control wire for the bulb portion of the tree.

Figure 14.12 Select the control wire for the bulb portion of the tree

18. (CLICK-L) on Change Sampling.

The following dialog box appears:

Figure 14.13 Sampling parameters

Set Number of Samples to 8.

This specifies the number of segments on the wire controlled by the control wire. Notice that when you change the sampling rate, the average segment length is automatically updated.

19. (CLICK-L) on the Set Sampling button.

20. Now, repeat steps 17 and 18, this time with the control wire for the trunk portion of the tree.

Specify 5 for the number of samples.

Once you've modified the sampling rate for the wire, you need to regenerate the solid of rotation.

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

22. (CLICK-R) on solid of rotation.

23. Select the control wire from which to generate the solid of rotation.

24. Complete the Solid of Rotation parameters dialog box as described in step 13.

You should now have a lower resolution version of the tree:

Figure 14.14 Lower resolution tree

Congratulations!

You've now learned some very useful new techniques for building complex shapes from other simpler shapes. Although the samples we used in this chapter were organic (plants) you could use most of the techniques described for a wide variety of tasks.

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

Another fine product from Nichimen documentation!