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CREATING EVERYDAY
OBJECTS
Tools, Techniques, and Tips
Starting Point
Go to www.wiley.com/college/chopra to assess your knowledge of creating everyday objects. Determine where you need to concentrate your effort.
What You’ll Learn in This Chapter
▲ How things are put together ▲ How to use components to make symmetrical models ▲ How to extrude around circles and along paths with Follow Me ▲ How to round off corners
After Studying This Chapter, You’ll Be Able To
▲ Create bilaterally symmetrical forms by building half of the form, creating a component, and copying and flipping the component ▲ Build radially symmetrical forms by modeling one portion of the form, making it into a component, and rotating copies of the component around a center point ▲ Design lathed forms using the SketchUp’s Follow Me tool ▲ Construct pipes, gutters, and moldings by extruding a 2D face along a 3D path ▲ Create rounded edges using fillets and the Follow Me tool
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INTRODUCTION
There’s more to life than modeling buildings. Even though SketchUp is excellent at letting you make models of built structures, you can use it to build just about anything you can think of—all it takes is time, ingenuity, and the ability to take a step back and break things down into their basic parts. SketchUp provides some fantastic tools for creating forms that aren’t in the least bit boxy, but these tools are not as obvious as Push/Pull and Rectangle, so most people never find them. This chapter is devoted to helping you discover SketchUp’s “rounder” side. In this chapter, you’ll learn about tools, techniques, and other tips for creat- ing forms that are distinctly unbuilding-like. Ideally, you will use these tools to push the limits of what you think SketchUp can do.
6.1 Modeling Symmetrically
First, take a hard look at the shape of the things you might want to model. Everything in the world (as you’ve probably realized) can be categorized as either of the following formal types:
▲ Symmetrical: Objects that exhibit bilateral symmetry are made of mir- rored halves. You are (more or less) bilaterally symmetrical, and so is your car. Another kind of symmetry is radial symmetry; objects that are radially symmetric have similar parts regularly arranged around a central point. Star- fish are good examples of this, as are umbrellas and apple pies. If you were going to build a model of something that exhibits some form of symmetry, building one part and making copies would be a smart way to do it. ▲ Asymmetrical: Some things—for example, puddles, oak trees, and many houses—aren’t symmetrical. There’s no real trick to making these things; you just have to settle in and get to work.
The fact is, a vast number of objects exhibit some kind of symmetry. This makes modeling a great deal easier, because it means you don’t often have to model things in their entirety. With SketchUp’s Components feature (described at length in Chapter 5), you can make a piece of something, copy it, flip it over (if neces- sary), and put it in position. Better yet, any changes you make to one part are automatically reflected in the others—because that’s what components do. You can take advantage of both bilateral and radial symmetry with SketchUp components. To do so, you just assemble those components as follows, depend- ing on what type of symmetry your object has:
▲ Bilateral symmetry: To make a model of something that’s bilaterally symmetrical, you just build half, make it into a component, and flip over a copy.
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▲ It’s fun. Modeling something and then watching it repeat in numerous other places is fun, and the overall effect impresses others. Somehow, peo- ple think you’re smarter if they see things appearing “out of nowhere.”
6.1.1 Building Bilaterally Symmetrical Forms Bilaterally symmetrical forms are everywhere. Most animals you can name, the majority of the furniture in your house, your vehicle—they can all be modeled by building half, creating a component, and flipping over a copy. Follow these steps to get the general idea of how to start building a bilater- ally symmetrical model in SketchUp (see Figure 6-2):
1. Make a simple box. You can do this however you want, but perhaps the easiest way is to draw a rectangle and push/pull it into 3D. 2. Draw a diagonal edge on the corner of your box. The point of this step is to mark one side of your box so that when you flip it over, you aren’t confused about which side is which. 3. Turn your box into a component. Chapter 5 has detailed information on how to do this, but here’s the condensed version: - Select everything you want to make into a component. - Choose Edit➪Make Component. - Name your component if you’d like, and then click the Create button.
Make a box Turn it into a component Move a copy over
Flip the copy Stick the two halves together
Figure 6-
Creating a bilaterally symmetrical model.
6.1 MODELING SYMMETRICALLY 163
4. Make a copy of your new component instance. The last part of Chap- ter 2 has information about moving and copying objects in SketchUp, but here’s a simple version: - Choose the Move tool. - Press Ctrl (Option on a Mac) to toggle from Move to Copy mode. You should see a little plus sign () next to your cursor. - Click your component instance. - Move your copy beside the original, and click again to drop it. Make sure that you move in either the red or the green direction; doing so makes things easier in the next step. 5. Flip the copy over. To do this, right-click the copy and choose Flip Along from the context menu. If you moved your copy in the red
direction in the previous step, choose Flip Along➪Component’s Red.
Choose Flip Along➪Component’s Green if you moved in the green
direction.
6. Put the two halves together. Using the Move tool (this time without Copy toggled on), pick up your copy from the corner and move it over, dropping it on the corresponding corner of the original. Take a look at the last image in Figure 6-2 to see what this looks like. Doing this precisely is important if you want your model to look right.
Now you’re set up to start building objects with bilateral symmetry! If you’d like, you can carry out a quick test to make sure things went smoothly (see Figure 6-3). To do so, follow these steps:
1. With the Select tool, double-click one of the halves of your model to edit it. 2. Draw a circle on the top surface and push/pull it into a cylinder.
If the same thing happens on the other side, you’re good to go. If the same thing doesn’t happen on the other side, it’s possible that one of the following situations holds true:
▲ You’re not really editing one of your component instances. If you aren’t, you’re drawing on top of your component instead of in it. You’ll know you’re in Component Edit mode if the rest of your model looks grayed out. ▲ You never made a component in the first place. If your halves don’t have blue boxes around them when you select them, they’re not compo- nent instances. Start a new file and try again, paying particular attention to step 3 in the preceding list.
6.1 MODELING SYMMETRICALLY 165
Make a polygon Define a wedge Erase the rest
Figure 6-
Draw a polygon to start, draw two edges to create a wedge, and erase the rest of your polygon.
6.1.2 Building Radially-Symmetrical Forms
It’s just as easy to model objects that exhibit radial symmetry as it is to model those with bilateral symmetry; all you need to do is start out slightly differently. The only thing you must decide before you start is how many “wedges”—or how many identical parts—your object is made of. To set yourself up to model something with radial symmetry, you start by modeling one wedge, then you make it into a component, and then you rotate copies around the center. Follow these steps to get the hang of it:
1. Draw a polygon with as many sides as the number of segments you need for the object you’re modeling. Here’s the easiest way to draw a polygon in SketchUp, as shown in Figure 6-4: - Choose Tools➪Polygon to select the Polygon tool. - Click once to establish the center (consider doing this on the axis ori- gin), move your cursor, and then click again to establish the radius. Don’t worry about being accurate right now. - Before you do anything else, type in the number of sides you’d like your polygon to have and press Enter.
or unhide them altogether. Just show your hidden geometry, select the
edges you want to unhide, and choose Edit➪Unhide➪Selected.
Distracting edges Use Eraser to hide
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2. Draw edges from the center of your polygon to two adjacent vertices (endpoints) on the perimeter, creating a wedge. To find the center of a polygon (or a circle), hover your cursor over the outline for a couple of seconds and move the cursor toward the middle; a center inference point should appear. **3. Erase the rest of your polygon, leaving only the wedge.
- Turn your wedge into a component.** Check out step 3 in the previ- ous section for instructions on how to do this, or read the first part of Chapter 5. 5. Make copies of your wedge component instance with the Rotate tool (see Figure 6-5). Just like with the Move tool, you can use the Rotate tool to make copies. You can even make an array (a series of copies that are equally spaced apart) than one copy at a time). Here’s how to do it:
- Select the edges and face of your wedge.
- Choose Tools➪Rotate to select the Rotate tool.
Make more copies
Click to define center of rotation Click to start rotating
Press Ctrl (Option on Mac) to rotate copy
Figure 6-
Use the Rotate tool to make copies of your wedge component instance.
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6.2 Extruding Shapes with Follow Me
Follow Me is an excellent example of a powerful SketchUp tool with an under- whelming name. The problem that faced the software designers when they were trying to determine what to call this feature was this: It does what other 3D mod- eling programs dedicate two or three other tools to doing. Thus, the designers chose an unconventional name because Follow Me is a wholly unconventional tool. In the following sections, you’ll learn how to use Follow Me to create a number of different types of shapes. Examples of these shapes are shown in Figure 6-6 and are as follows:
▲ Bottles, spindles, and spheres: These are all examples of lathed forms, or 3D forms created by spinning a 2D shape around a central axis. These can be created by spinning a 2D profile (shape) around a central axis to create a 3D model.
- When building a symmetrical object, it is quicker to work with ________.
- Putting two halves together ________ is important for your model to look right.
- What is the easiest way to make a simple box?
- If the rest of your model other than what you are working on is grayed out, you are in ________________ mode.
S E L F - C H E C K
Figure 6-
Follow Me lets you create all kinds of different shapes.
JWNJ004_ch06_159-186.inddJWNJ004_ch06_159-186.indd 168168 7/19/077/19/07 5:16:35 PM5:16:35 PM
▲ Pipes, gutters, and moldings: If you look closely, all three of these things are basically created by extruding a 2D face along a 3D path; the result is a complex 3D form. ▲ Fillets and other cut-away profiles : A fillet is a thin strip of material. In SketchUp, you can cut fillets and other shapes away from the edges of forms to create rounded edges. This can also be accomplished using Fol- low Me.
6.2.1 Using Follow Me
At its core, Follow Me lets you create forms that are extrusions. It’s a bit like Push/Pull, except that it doesn’t just work in one direction. You tell Follow Me to follow a path, and it extrudes a face all along that path. This means that you need three things to use Follow Me:
▲ A path: In SketchUp, you can use any edge, or series of edges, as a path. All you have to do is make sure that they’re drawn before you use Follow Me. ▲ A face: Just like with Push/Pull, Follow Me needs a face to extrude. You can use any face in your model, but it needs to be created before you start using Follow Me. ▲ Undo: Imagining what a 2D face will look like as a 3D shape isn’t easy—it usually takes several tries to get a Follow Me operation right. That’s what Undo is for, after all.
Follow these steps to use Follow Me; refer to Figure 6-7 to see how the steps work:
1. Draw a face to use as an extrusion profile. In this example, we’re cre- ating a pipe, so our extrusion profile is a circular face.
Select the whole path Click the face with Follow Me
Figure 6-
Using Follow Me to create a simple extruded shape.
6.2 EXTRUDING SHAPES WITH FOLLOW ME 169
Now your axis of rotation is a line right through the center of your circle.
- Click anywhere on the edge of your circle, and then move your mouse over a little bit.
- Type in 90 and press Enter. **3. Make sure that one of your circles is selected.
- With the Follow Me tool, click the circle that’s not selected once (see Figure 6-9).** Now you have a sphere. The Follow Me tool “lathed” your circular face around the path you selected—the other circle.
Note, however, that if you really need a sphere, the easiest way to get one is in the Components dialog box. The Shapes library that comes installed with SketchUp has a selection of spheres (and cones and other things) you can choose from. Under normal circumstances, you only have to model half a profile to use Follow Me to make it three-dimensional. Figure 6-10 shows a few different examples of 3D objects.
Click and hold down mouse button Drag here
Figure 6-
Using the Rotate tool to make a rotated copy of a circle.
Figure 6-
Clicking one circle with Follow Me while the other one is selected produces a sphere.
Select one circle Click the other with Follow Me
6.2 EXTRUDING SHAPES WITH FOLLOW ME 171
172 CREATING EVERYDAY OBJECTS
6.2.3 Creating Extruded Shapes Like Gutters and Handrails Much of the time, you’ll want to use Follow Me to create geometry (edges and faces) that’s attached to another part of your model. An example of this might be modeling a gutter that runs all the way around the roof of a house. In this case, you’re likely to already have the path along which you want to extrude a profile (the edge of the roof ). When you’re using Follow Me to extrude a face along a path that consists of edges that already exist as part of your model, there are two things you should always do:
▲ Before using Follow Me, make the rest of your model a separate group. Follow Me can sometimes mess things up, so you want to be able to keep the geometry that it creates separate, just in case. ▲ Make a copy of your extrusion path outside your group. There’s a consequence to working with Follow Me on top of a group: The edge (or edges) you want to use as an extrusion path will no longer be available, because you can’t use Follow Me with a path that’s in a separate group or component. What to do? You need to make a copy of the path outside the group, and then use the copy to do the Follow Me operation. Here’s the best way to make a copy of the path:
- With the Select tool, double-click your group to edit it.
- Select the path you want to use for Follow Me.
Figure 6-
A few examples of lathed objects created with Follow Me.
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Drawing Your Profile in Place Consider that you have a model of a house. You want to use Follow Me to add a gutter that goes all the way around the perimeter of the roof. You decide to draw the profile in place (right on the roof itself ), because the edges of the roof are drawn parallel to the colored drawing axes. This means that you’ll have an easier time using the Line tool to draw “in midair.” The trick to drawing an extrusion profile that isn’t on the ground is to start by drawing a rectangular face. You then draw the profile on the face and erase the rest of the rectangle. Figure 6-11 shows how you would draw the profile of a gutter directly on the corner of a roof; the steps that follow explain the same things in words:
1. Zoom in on what you’re doing. Get close, and fill your modeling win- dow with the subject at hand. 2. Using the Line tool, draw a rectangle whose face is perpendicular to the edge you want to use for Follow Me. This involves paying careful attention to SketchUp’s inference engine; watch the colors to make sure that you’re drawing in the right direction. 3. Use the Line tool (and SketchUp’s other drawing tools) to draw your profile directly on the rectangle you just created. The important thing here is to make sure that your extrusion profile is a single face; if it’s not, Follow Me won’t work the way you want it to. 4. Erase the rest of your rectangle, leaving only the profile.
Drawing Your Profile Somewhere Else The awful thing about handrails is that they’re almost always at funny angles, and thus not parallel to a colored axis. In such cases, it’s not convenient to draw your extrusion profile in place. Here, it’s best to draw the profile on the ground and move it into position afterwards. Here’s the trick: Draw a “tail”—a short edge—perpendicular to your extrusion profile. You can use this tail to help you line up your profile with the edge you
338 faces 116 faces 52 faces
want to use as an extrusion path for Follow Me. The following steps, and Figure 6-12, describe how you would draw and position a profile for a handrail:
**1. Draw your extrusion profile flat on the ground.
- Draw a short edge perpendicular to the face you just drew.** This “tail” should come from the point where you want your profile to attach to the extrusion path.
Watch the color inferences
Draw a rectangle Draw your profile on the rectangle
Erase the rest Use Follow Me
This part of roof
Figure 6-
Drawing an extrusion profile in place by starting with a rectangle.
6.2 EXTRUDING SHAPES WITH FOLLOW ME 175
5. With the Rotate tool, rotate your profile into position. Here’s where you need to use a bit of skill. See the nearby sidebar, “Wrapping Your Head Around the Rotate Tool,” for guidance. The Rotate tool is easy to use when you get the hang of it. 6. Explode the group you created in step 3, and delete your tail. To explode a group, right-click it and choose Explode from the context menu.
WRAPPING YOUR HEAD AROUND THE ROTATE TOOL
In the last version of SketchUp, the software’s designers introduced a feature that allows you to establish your axis of rotation (the invisible line around which you’re rotating) while you’re using the Rotate tool. This makes it many times easier to rotate things. By default, the Rotate tool “sticks” itself to whatever plane you happen to be hovering over—that’s why it changes color as you move its big, round cursor all over your screen. When it’s blue, its axis of rotation is the blue axis; the same goes for red and green. When it’s black, its axis of rotation doesn’t line up with any of the colored drawing axes. If you want to show SketchUp the axis of rotation you want to use while you’re using the Rotate tool, you can. In this case, using Rotate goes from being a three-step operation to a five-step one (refer to the following figure for a visual explanation):
1. Click once to establish your center of rotation, but don’t let go —keep your finger on your mouse button. 2. Drag your cursor around (still holding the mouse button down) until your axis of rotation is where you want it. As you drag, you’ll notice your Rotate cursor changing orientation; the line from the center of the cursor to your mouse is the axis of rotation. 3. Release your mouse button to set your axis of rotation. 4. Click (but don’t drag) the point at which you want to “pick up” what- ever you’re rotating. 5. Click again to drop the thing you’re rotating where you want it. Whew! It takes practice, but it’s worth it. The efficiency you gain by being able to rotate things in free space is huge. Here are two more things you should also know about Rotate, while we’re on the subject: ▲ Type in a rotate angle during or after you rotate something. Check out the section about modeling with accuracy in Chapter 2 for more information on using the Value Control Box (VCB) to be precise while you’re modeling. ▲ Press Ctrl (Option on a Mac) to make a copy. This works just like it does in the Move tool, which you can also read about in Chapter 2.
6.2 EXTRUDING SHAPES WITH FOLLOW ME 177
178 CREATING EVERYDAY OBJECTS
6.2.4 Subtracting From a Model with Follow Me What if you want to model a bar of soap? Or a sofa cushion? Or any object that doesn’t have a sharp edge? The best way to round off edges in SketchUp is to use Follow Me. In addition to using this tool to add to your model, you can also use it to subtract from your model. Here’s how it works: If you draw an extrusion profile on the end face of a longish form, you can use Follow Me to “remove” a strip of material along
Click to rotate
Click to finish rotating
Click Drag to locate axis of rotation
Release mouse to define axis
