CAP 201a - Computer Animation I

Lesson 1 - Basic Concepts and User Interface, First Model

Objectives:

This lesson introduces the student to basic concepts and the software used for the course. Objectives important to this lesson:

  1. Overview of the user interface: viewports, panels, and tools
  2. Manipulating the viewports : panning, zooming, orbiting
  3. Command panels and Graphite tools
  4. File management
  5. First modeling project
  6. Manipulating an object
Concepts:

Before we begin, understand that these notes are not a substitute for your textbook. They are provided here for several reasons:

  • to enhance the lessons in the text with more lecture material
  • to correct errors in the text
  • to provide questions that you must answer as part of your assignment

You must use these notes in conjunction with your textbook to get the intended experience from this class.

The first chapter of the Essentials text omits several concepts that previous texts presented as background for the study of animation. We will look for some of this material in the second text for this course. These concepts will include:

  • Basic Terminology
  • Production cycles
  • Image types and color depth
  • Broadcast formats and resolution

Several times the authors use a term for a button (or other control) that is different from the mouseover title that you will see in 3DS Max for that button. This may happen because Autodesk has renamed the button since the text was written, or because the authors are remembering an old name for the same control. In either case, get an idea what the control does, and use it as necessary without regard to what it might be have been called in the past. The art used on buttons changes a bit from one version to another as well, so don't expect that you will always see exactly what appears in a text, a video, or a screen capture.

The first lesson in the text is about the 3DS Max 2012 interface. Much of it is the same as previous versions, but there are a few changes we will see as the lessons proceed.

  • Like many programs, 3DS Max now has an application button instead of a File menu. It contains menu choices that you would have found on a File menu in the past.
  • Like some programs, there is now a Quick Access toolbar just to the right of the application button. Among other controls, it presents buttons to Save, Undo, and Redo.
  • Viewports are also called modeling windows by your text.
    By default, you get four viewports when you open the program, set to Top, Front, Left, and Perspective views. Note that a ViewCube tool is available in the upper right corner of each viewport. The text advises us that this tool will not appear in viewports set to display particular camera or light views.
  • The text discusses the x, y, and z axes of the viewports on page 4. It describes the x axis as left and right, the y axis as up and down, and the z axis as into and out of the screen. That description only applies to the your current relative view of the scene. What do I mean by that?
    Quick exercise 1:
    1. Open 3DS Max.
    2. Create a box in the Perspective viewport, making the proportions close to a cube. (It doesn't have to be a cube for this exercise, but it is good practice to make one.)
    3. In the tool bar, select the Move tool.
    4. Observe the red, green, and blue (RGB=XYZ) handles of the Move gizmo in each viewport.
    5. Now, select the box in each of the other viewports, one after another. Watch the handles change the directions they point in.

    The axis directions are relative to your current view, by default. (You can change this but there is usually no need to do so.) Be aware of this. Which axis points up, left, or away? It depends on your current view of the scene.
  • On page 5, the text explains that you can select a viewport by clicking it in an unpopulated area (no objects there). It also explains that doing so will deselect the currently selected object or objects. This is often a bad thing. It should be your default behavior to select a viewport by the second method described here, right-clicking it, which does not deselect the current selection set.
    The what? The "current selection set" means all the objects and/or subobjects that are currently selected. As you continue to model, you may find it useful to name and save sets of selected objects, so you can select them all again without fear of missing any.
  • The right mouse button can be clicked to open a (context sensitive) Quad Menu for most objects in a scene, as well as for the scene itself.
  • Note the instructions in the illustration on page 6 about using the the mouse wheel and middle mouse button.
    • Roll the mouse wheel to zoom in or out.
    • Drag with the middle mouse button to pan left, right, up, or down in a viewport.
    • Alt-drag the middle mouse button to arc rotate. What is that? On page 11, the authors explain it again, but they call it orbiting instead of arc rotating. Both terms mean the same thing. Orbiting treats the objects in the scene like the sun, and the camera like a tide-locked planet orbiting them as you move the mouse.
      (Astronomy lesson: a tide-locked body keeps the same face pointing toward the center of its orbit as it continues in that orbit. This is why the moon always shows the same side to Earth. In a similar way, your camera will continue to point toward the objects it orbits, rotating slowly as it traces out the arc of the orbit. Now you should understand both names for this technique.)
      You may ask why don't we just use the ViewCube. The ViewCube tool will rotate the entire scene, as opposed to moving your camera around the selected objects. Try it, and you will see a big difference.
  • In previous versions of 3DS Max, we used settings dialog boxes for operations like extruding or beveling a polygon. In this version of the program, you begin those operations the same way but instead of the dialog box that you saw in 3DS Max 2010, you now see a caddy interface, as described on page 8. Its use is similar, but it has fewer helpful labels. We will practice using this tool in the major project for this week.
  • Page 13 introduces the Graphite Modeling Tools ribbon, which you may not have used yet. It provides what some users think is easier access to the tools that appear in various command panels (Create, Modify, etc.) and menus (Quad menus, menu bar menus, etc.) elsewhere in the application. Lesson: there are usually several ways to do what you want to do in 3DS Max.

The text continues with its review of 3DS Max, reminding you that objects have parameters that vary from one object type to another, and you can change the value of each parameter to change the object. Some objects, such as editable poly objects, have subobjects, such as edges, vertices, and polygons. Some objects have a few subobjects that are unique to their object type..

The time controls at the bottom of the workspace have not changed. You probably did not use them much in previous classes, but that will change in this class.

The chapter ends with a discussion of file management. Like other design programs, 3DS Max can and should be told the name and location of a folder that will be the root folder for each project. This is because 3DS Max will create subfolders and files in that root folder as the project develops. If you do not keep your projects in separate folders, you will eventually have subfolders that contain the pieces of many projects. This will make it difficult to share work in a team, to copy or back up work, to transport work from one computer to another, and to definitively say what files are needed for a given project.

The classroom has been reconfigured for fall 2012. There are no longer any removable drives for students. You may be able to write to the C: drive of your workstation, but any files you save there will be deleted at the next reboot. This means that you must make sure your work has been copied to a removable USB drive or your student network drive before you shut down your workstation, or those files will be lost.

Best practice:

  1. Make a folder for each new project before you start the project.
  2. Click the Application button, Manage, Set Project Folder.
  3. Select the folder that will hold the subfolders and files for your project. When you create a new scene, it will go in the Scenes subfolder inside your project folder. (You don't have to make the Scenes folder. 3DS Max will make it and other required subfolders.)
  4. When you are done with your work, copy the project folder to a safe location. After a reboot, copy the project folder back into place, and set the project folder location again.

Make life easier on yourself and others: make use of the information in the text about setting project folders, and incrementally versioning your project files.

The second chapter takes you immediately into a project with 3DS Max. This is a good idea, but it leaves out all the valuable material you should think about before beginning a project. This was discussed at this point in the last version of this text. For a few paragraphs here, I will present some of these ideas, since you should consider them now, before you dig into more complicated projects.


 

The chapter turns to a modeling project: that constructs a chest of drawers model. The text also calls the chest of drawers a dresser. Call it whichever you like. I will warn you that there are some errors in the instructions for this project. Most textbooks suffer from this problem, perhaps because proofreaders do not actually use the programs that authors describe. We should expect this in any textbook.

Before you begin work in 3DS Max, you should know as much about the object you will be modeling as you can know. Reference photos, sketches, physical models, and measurements would all be sensible things to accumulate before modeling.

Quick Exercise 2: study the reference picture of a chest of drawers on page 20 for 30 seconds. I will wait here.

Back already?
Question 1:
a. How many drawer rows are in the chest?
b. How many drawers are in the chest?
c. How many knobs are on the chest and what do they look like?
d. What does the top of of the chest look like?
e. What does the back of the chest look like?

This is to show you that one look may not be enough, and one reference photo is unlikely to be enough. You will do better modeling if you have multiple references to work from, and if you continue to use your references while you are modeling. For this project, I will expect some approximation, but this is a good time to become more precise.

In all of the exercises that follow (for the rest of your life), watch for decimal points, and for negative signs. Missing either of those things when setting a value will create a huge difference in your results. Also watch for errors in the text: one is coming up.

Project Exercise 1: Top of the dresser

  1. In step 1, the text says to begin a new scene with File, New, New All. Be aware that you can also start a new scene with File, Reset. This may not seem like a sensible command to start your scene over, but that's what it does.
  2. In step 2, the text says that your Perspective viewport should be set to Smooth + Highlights by default. In the sidebar on page 21, it explains that Smooth mode is called Realistic when 3DS Max is installed with the default Nitrous driver set. This is what I see on my computer, and what you may see on yours as well.
    Toggle the Edged Faces view for the Perspective Viewport as instructed. This will give you a better view of the object and sub-objects in this project. Open the Create panel, Geometry heading, and select Box.
  3. In step 3, tell the program you are going to make a box. Do not draw it in the scene. You will use a different method in the next step.
  4. Make sure you use the Keyboard Entry rollout, not the Parameters rollout. They are similar, but there is no Create button on the Parameters rollout, which is used in this step to create your preconfigured box at the default location in the scene.
    Question 2: Where is the default location in this scene?
  5. Use the Modify panel to set the height segments of the box to 6. Remember to always use the Modify panel, not the Create panel, to change an object.
  6. Open the Graphite ribbonThe instruction in this step is incomplete. To use the Graphite Modeling tools, if the ribbon is not already displayed, first open the tool bar by clicking the button with a down arrow to the right of the words "Object Paint". Select the Graphite Modeling Tools tab on this new tool bar. The text tells you to click the Polygon Modeling tab, which is at the bottom of the Graphite Modeling Tools tab, on the left end.
    Find the Convert to Poly button on this tab and click it. (And wonder why someone thought this was easier than using the Quad menu for the object to do the same thing.)
  7. Polygon subobject buttonLook at the subobject selection buttons that are now live in the top row of the Graphite Modeling tools tab. They are identical in shape to the same buttons that have appeared in the Modify panel, but they are different colors. Click the one for Polygon mode, which is the icon of a square. The text says you could also press 4 on the keyboard to go to the Polygon sub-object mode. This did not work for me, but I was not disappointed. I think it is easier to use the visual cues in front of us than it is to remember hot keys like this.
  8. After you have done this, click the polygon on top of the box, as instructed. This is most easily done in the Top viewport.
    The next several steps will work a lot better if you adjust your Front viewport so that it presents a view similar to the illustration on page 24. You want to be able to see each bevel as it is applied, and as you modify it before locking it in.
  9. Step 8 is incorrect. Drop down for Bevel settingsThe arrow for settings is not below the Bevel button in the Graphite tools, it is to the right of that button. (The authors probably wrote that about an older version of the program.) Click it, then click the Bevel Settings option that appears like a drop down menu item. The Bevel settings caddy will appear. You could have clicked the Bevel settings button that is on the Modify panel, and the same caddy would have appeared.
    I will warn you that if you have ever used Bevel settings on any object on this computer, the tool will automatically apply the last value used in it on the current model. This is a disconcerting event if you are not expecting it. (This odd behavior is true for Extrude, Inset, and other such settings as well.) Don't worry if this occurs, just continue with the instructions.
  10. The book says to enter the Height and Outline Amount values given.
    Since there are no labels on the fields in the caddy, which is which? Plus sign button on Bevel caddyThe names of the Height and Outline input fields will show when you mouse over those fields, replacing the word "Bevel" in the dark field at the top of the caddy. The field you hover over replaces the word "Bevel" with the current value it holds: Group, Local Normal, or By Polygon. Change the values as indicated, then click the Plus sign button, which stands for Apply and Continue. That will apply the action, but keep the caddy open. It may also apply the same bevel a second time. If it does, you will modify that bevel before approving it in the next step.
  11. Enter the Height and Outline Amount values given. Click Apply and Continue, which applies the action, but keeps the caddy open.
  12. Step 11 contains an incorrect value. The Outline value should be set to -0.3, not -0.03. You can see in Figure 2.9 that this is the value the authors actually used, if you have a magnifying glass handy. The value given for Height is correct. Since this is the last bevel layer, set the values and click OK (the check mark button) to accept the value and close the caddy. Your work should look a lot like the illustration on page 25. Zoom and pan as needed to check it.

    If anything goes wrong Undo is your friend, but it sometimes gives you unpredictable results. When in doubt, save more often.

    Save your project before you begin the next portion of it. (Yes, really. Do it now.)

  13. In step 12, the authors tell you to switch to the Edge subobject mode. You can click the icon for edges in either the Graphite panel or the Modify panel. The authors tell you to select the two edges indicated by red lines on page 26. They assume you will remember to hold down a control key when clicking the second of two objects you want to select. (This is a standard Windows technique.)
  14. Loop button on Graphite ribbonIf you have selected the two edges indicated in the last step, find the Loop button on either the Graphite panel's Modify Selection tab, or on the Modify Panel's Selection rollout. Click that button once. The Loop command extends your current selection by adding all connected edges that form a loop around the model to your selection set.
  15. Find the Edges tab in the Graphite panel. (On my computer it is the fifth section from the left end of the Graphite ribbon.) Find the Chamfer tool, click its drop down arrow, then select the Chamfer Settings option. This should open the Chamfer caddy.
  16. Explore the Chamfer caddy, and enter the values given in the text. There is only one set of values this time, so click OK (the check mark) when the values are correct.
  17. Save again, incrementally, before continuing with the next exercise in this project.

Project Exercise 2: Drawers

The next section models drawers onto the chest. These drawers are not meant to open, so we will just model the appearance of a set of closed drawers. Assume that no actor is intended to open the drawers in the game or video you are making this dresser for. That is a valid reason to skip the level of detail that would be needed for an actual prop as opposed to a piece of stage dressing. (A prop is something an actor uses. Stage dressing is something that just appears in a scene.)

  1. Before you start the next sequence, you will probably want to select the Front viewport, then pan and zoom as necessary to clearly view the entire front of the dresser. Note: if you try to zoom with the mouse wheel and you can only get too close or too far away, hold down an Alt key while rolling the mouse wheel for finer control over the zoom.
    If the dresser is still selected, you can switch to Polygon subobject mode by clicking the correct icon on either the Graphite panel or the Selection rollout of the Modify panel. Do so, then use Ctrl-click to select all six polygons on the front of the dresser. Another way would be to marquee select those polygons at once.
    The instruction in the text at the end of this step in irrelevant.
  2. Chest at end of exercise 2Use the Inset Settings caddy as instructed to inset the six polygons as a group. This will decrease the height of the top and bottom polygons, and decrease the width of all of them. It will appear that a new border of polygons has surrounded the original ones. Ignore the authors' suggestion to load their version of the scene at this time.
  3. Open the Bevel Settings caddy as instructed. Step 3 seems to think that the drawers will look more natural if they are set back into the chest slightly. This is why the Bevel Height value used is a negative number (into the object): -0.5. Set the Bevel as instructed but click the OK button (check mark) when you are done, not the Plus sign.
    Continue with another Inset operation, but you will like it better if you set the Amount value to 0.2 instead of 0.6.
  4. Step 4 tells us that you are going split the top drawer into two drawers. This matches the reference. Press F2, so that the selected polygons are shown as red outlines instead of solid red. (Wireframe instead of shaded.) Doing this will let you see and work with edges a little better. Change to Edge subobject mode, then select the top edge and bottom edge of the top drawer. The next step creates an new edge that bridges the two selected.
  5. On the Graphite panel, find the Loops tab, and open the Settings option for Connect. (This set of tools is not visible unless you are in Edge mode.) When I did this, the default settings for the Connect tool were already set to 1 Segment, 0 Pinch, and 0 Slide. Use these settings and click OK. You will see a new edge connecting the two selected edges, at their midpoints.
  6. The authors tell you to select two polygons. Did you realize that you need to switch to Polygon subobject mode first? If you do this in the Front viewport, you may not think you have selected anything, unless you also press F2 to go back to shaded mode. Apply an Inset to the two new polygons (they were one), as instructed. Make the Inset Amount 0.25, and this time, make sure to select By Polygon for the Inset Type value.
  7. Repeat the instructions in step 6, this time for each of the remaining drawers in the chest.
  8. In step 3, you extruded all the drawers into the chest. This was really for the supporting wood around the drawers. Now, select all of the drawer polygons on the front of the chest. Click the Settings button for Extrude. Make the Extrusion Amount 0.7, and make the Extrusion Type By Polygon. This will move each of the drawers in the project a little bit out from the front of the chest.
  9. Save incrementally.

Project Exercise 3: Bottom details

  1. In step 1, the authors tell you to select the polygon on the bottom of the box. They do not tell you how to get a view like the one shown on page 35. For this step, you just need to see the bottom of the chest. You could change any viewport to a Bottom view, or you could just use the Viewcube, Pan, and Zoom controls to get a nice view. Do this whichever way makes sense to you and select the polygon on the bottom of the chest.
  2. Use the Settings for the Extrude button on the Polygon tab of the Graphite panel to Extrude to a Height of 2.5 and click OK. As the text notes, a new section is added to the box.
  3. The polygon you just extruded should be the only one selected. If not, select only that one. Open the Settings caddy for the Inset tool. Set the Amount to .6 as instructed and click the Check Mark (OK). The polygon will appear to shrink.
  4. Click the Settings button for the Extrude button again. Set the Height value to -2.0, which will cause the polygon to move toward the top of the chest.

    This is a good place to pause and save again. Remember to save your file with a new, incremental name, so you have more than one place to go when you need to go back in time.

    The text starts a new set of steps on page 37 to carve away sections of the extruded material, so the model will look more like the chest detail on page 20. To do this, you will need to be able to rotate the model in space, and you will need to be able to select and deselect separate polygons in the model.

  5. Adjust the Front viewport so that you can see the new section of the chest from that angle (straight on). Select the Create panel, Shapes tab, Rectangle button.
  6. The text says to create a rectangle with a Length of 3 and a Width of 26. Do it the easy way.
    1. First, draw a rectangle that is about the right size in the Front viewport. (Why the Front viewport? So that length and width get their meanings from that viewport.)
    2. Second, switch to the Modify panel and set the Length to 3 and the Width to 26.
    3. Third, select the Move tool. Note two useful things: the move gizmo is centered on the rectangle, and the chest is (should be?) centered in the scene.
    4. Fourth, adjust the Move gizmo horizontally so that the y-arrow is lined up with the black Y axis line marking the center of the scene, which is also the center of the chest. (I will show you an easy way to do this in class.)
    5. Adjust the vertical position of the rectangle by eye, so that there will be an appropriate border in the bottom board when we use the rectangle for a cut out template.
  7. In the Modifier list, right click the rectangle object, and convert it to an Editable Spline, which the authors do not explain for five more pages. A spline is a modifiable line that has vertices and segments for subobjects. Select Vertex subobject mode.
    Question 3: There are at least two ways to select Vertex subobject mode at this point. Explain two ways to do this.
  8. Select both vertices at the top of the rectangle. Find the Geometry rollout on the Modify panel, then drag that panel up until you can see and click the Fillet button. (What's a fillet? It's a rounded corner. Typically, it's a rounded interior corner.)
  9. The text says to drag a vertex to create a fillet whose value is 0.9. You could use the value entry box to the right of the Fillet button instead, if you want it to be exact.
  10. The text says to select the rectangle shape. You can't just click it, because you are in subobject mode. Look at the Modifier list. You should see the object at the root of its subobject types list. Click the object in that list. (It is now called Editable Spline.)

    Click the drop down arrow for the Modifier list. Find and add the Extrude modifier.
    Set the amount value for the Extrude modifier to about 30. It does not have to be this large. It only has to be big enough to stick out in front and in back of the chest when placed under it.
    Move the object so that is sticks out as indicated on page 40. Be careful not to move it off the center of the chest. Mine is shown as the yellow object in the image below.
  11. Step 11 says to repeat the process above to make a cutout template for the sides of the chest. Do so, and wind up with a second filleted, extruded rectangle whose top surface is in line with the first one, but oriented so that it sticks out from under the right and left sides of the chest. Mine is the blue object in the image below.

    Cutout forms placed under chest

The image above looks a little funny but it is right. The cutout templates extend below the surface of the floor, but the chest does not. Obviously, the templates did not need to be that "tall", but it will not hurt. If you only made them tall enough to reach the floor, you might make a mistake and make them too short, leaving a funny polygon between the legs of the chest. Making them a little tall is a better practice, unless there is a danger of cutting into something below them.

The text pauses to introduce the reason you made the two extruded forms and placed them under the chest. You are told to use a ProBoolean operation to subtract the forms from the chest, cutting away the parts of the chest that match the forms. This is your last chance to move them before beginning this operation, so check their placement in as many views as necessary before continuing.

The instructions for the procedure in the text are good, but on my computer, the final step did not work. If this is the case in class, we will explore using the Boolean operation instead of the Proboolean operation. The biggest difference between them seems to be that you are allowed to select a series of objects to subtract in a Proboolean operation, but you can only select one object to subtract in a Boolean operation. This would require you to do the Boolean operation twice in this example, once for each extruded form.

After performing the necessary operation from pages 41 and 42, save again. There is only one exercise left, but it seems to have been broken into three. More new skills.

Project Exercise 4: Creating knobs

Page 167 shows a reference image of a knob that is like the ones you want to put on the model. The text introduces you to several skills needed to create such a knob.

  1. Step 1 reminds you to place the knobs on the drawers. To that end, you are told to start in the Left viewport, where you can draw an outline for a knob.
    Actually, you could start in any viewport, since you are going to have to move the knob anyway.
    If you look carefully at the picture on page 44, you will see that you only have to draw half of the knob. The half drawing will be rotated with the Lathe modifier to generate a 3D shape from your 2D drawing.
  2. On the Create panel, choose Shapes, Line. (You will draw a spline outline for the knob.) Note that the authors want you to set the Drag Type for your line as Bezier. This is a kind of control point for a line that lets you affect how the line curves into and out of that point. Much prettier than hard angles.
  3. Back in the viewport, you will click along an imagined line, similar to the pattern on page 45. It may be easier to pan and zoom first, to give yourself enough room to work. Also, remember that you can maximize the current viewport by pressing Alt-W. (It does not really matter if you draw the knob attached to the drawer, since you can move and rotate it once it has been created.)
  4. Step 4 tells you that you can either:
    • make the spline a closed figure (as shown on page 45) by clicking your first point again, or
    • you can leave the spline as an open figure by making your last click anywhere short of the first point, and right-clicking to end the spline creation
    The authors tell you that you can edit the curve of your spline, but they do not tell you how. As I mentioned above, bezier points are used to affect the way the line curves. You should save, then experiment with this idea, using vertex subobjects.
  5. In the modifier stack for the project, find the object for your line, and open it as instructed on page 45. Note the sub-objects listed: vertex, segment, and spline.

For some reason, the authors continue the exercise here with a new series of numbered steps. This seems unnecessary. Assume that step 1 below follows step 5 just above, to stay in line with the exercise so far.

  1. Choose the vertex sub-object. Click the Select and Move tool, and use it to move a vertex in a direction that will make the line more like the reference image.
  2. When the line is acceptable, select the line object again. Then, add the Lathe modifier by the method described on page 46. The text is convinced that you can adjust the resulting shape of the lathed line by clicking Max or Min button on the Align section of the Parameters rollout. You may find that it is more useful to click the axis buttons under the Direction section to control which axis the Lathe rotates the line around.
  3. Use the Weld Core option to remove the extra vertices that were caused by Lathe rotation. (Trust me, they are in center of the knob.)

The text does not discuss using the Scale tool in detail, but it is very likely that you will need to use both the Scale and Rotate tools to make the knob match the dresser and to place it on a drawer properly.

Let me make an observation about the Scale tool. Like several tool icons on the tool bar, the Scale tool has a flyout (click the small triangle in its lower right corner) to switch between its operational modes. In this case there are three modes. We could refer to the three modes as Uniform Scale, Non-uniform Scale, and Uniform Volume.

The third choice is valuable for "classic" animation, such as squashing and stretching a bouncing ball that must maintain its volume throughout its deformations. The other two are no longer very different.

  • You can scale an object in one direction (non-uniform) by dragging one handle of the scale gizmo.
  • You can scale an object in two directions (non-uniform, unless it is two dimensional) by dragging a bar on the gizmo that connects two axes.
  • You can scale an object in all directions (uniform) by dragging the central core of the gizmo.
  • These facts seem to be true regardless of whether the uniform or non-uniform mode is active.

The tool did not work this way in previous versions of the program: it used to make a difference which mode was active. Now, it does not seem to matter. When you are fixing the knob, you may want to use both kinds of scaling: uniform scaling to size it, and non-uniform scaling to shape it.

Finally, the last pages in this part of the chapter. The text realizes that you must make copies of your knob, so instructions are on page 47 and 48. 3DS Max can do three kinds of copying, but the generic term it uses is not "copy", it's "clone".

  1. Use the Move and Rotate tools as needed to place the knob on one of the top drawers. (If the knob is too big, scale and move it again.) Size, shape, rotate, and move the knob into a position that matches the reference art.
  2. With the one and only knob selected, start the clone procedure by clicking the menu option Edit, Clone. (This is not the only way to start a clone operation, by the way.) There are three choices in the clone dialog box that produce different results:
    • copy - copies of an object are independent of each other and independent of the original object
    • instance - instances are linked objects; changing one instance will affect all other linked instances, including the original
    • reference - reference objects link down: you can change the base object (the original one) and affect all the references, while you cannot change a reference itself

    This time, the text says to make instance clones.
  3. Position the new instance in the correct place on the other top drawer.
  4. Follow the directions to make the rest of the knobs. I will show you a better way in class.

Save your project again and show me the sequence of saves on your computer.