CAP 201a - Computer Animation I
Lesson 6 - Chapter 7, Materials and Mapping (part 2)
This lesson returns to the Material Editor, using it with the Red Rocket model. Objectives important to this lesson:
- Mapping the Rocket
We will cover this chapter in two parts. This lesson will cover topics starting on page 333.
The text provides a description of the real Red Rocket toy's wheels on page 333. Note the words used on this page and the next to describe the wheels: white, smooth, shiny, reflective. Compare these to the words describing the tires: black, still shiny, rough, distorted by bumpiness, slightly matte. The hubs of the wheels have yet another texture and look: red, shiny, plastic. These are descriptions that should be handled by mapping a different material to each part of the wheels. Each wheel is only one object however, so the text recommends using Multi/Sub-Object materials.
Project Exercise 1: Selecting polygons and named selection sets
This exercise starts on page 334. It has problems, so read it, then come back here for corrections.
- Open the file specified on page 334 to start at a known point. Note the instruction to leave parts of the rocket hidden for now. Press F4 to see edges, and press F2 to see selected polygons better.
- You should only see a wheel and an axle. Select the wheel as instructed. Go to Polygon subobject mode.
- Look carefully at the illustration on page 335 of the Select Region flyout. Choose the fourth item in the flyout list, which is the Lasso selection tool. Note that the text leaves out telling which of the three kinds of polygons to select. That's because this step is for practice. Note the gray box that follows this step in the text: it informs you that the Ctrl key modifier will let you add polygons to your selection set (standard Windows feature) and the Alt key modifier will let you remove polygons from your selection set (not a standard Windows feature).
- Switch to the Select Object tool. Try using Ctrl-click and Alt-click to add and remove polygons from your selection set.
- The next technique is good. Too bad the instructions don't work.
- Change to edge selection mode.
- You can Arc Rotate to get a view like the one at the top of page 336, but you will do better just to use the Top viewport and watch the others.
- Do not select an edge as shown in figure 7.64 (the dark line in the circle). Instead, click outside the wheel to deselect any edges already selected.
- Click one of the long edges across the tread of the wheel. (See the red line in the first image below.)
- Click the Ring button. The same edge in all positions around the wheel will be selected. (As shown in the second image below.)
- Click the Grow button three times. The selection set will grow toward the axle, in each direction, with each click. (The result is shown in the third image below.)
|d. Click an edge
||e. Click Ring
||f. Click Grow 3 times
- Hold down a Ctrl key and click the icon for Polygon subobjects. (It has to be the icon, not the word in the modifier stack.) This will select the polygons defined by the currently selected edges.
- Save the selection set by clicking in the dropdown box that says Create Selection Set, typing a name, and pressing Enter. The book says to call it Wheel_Black, but this name has already been used. Call it Wheel_Tire instead. This is more accurate. The selection set I have told you to make is more accurately the tire. The Wheel_Black set that came with the file is accurate for the parts of the wheel that will be black.
- The file already has the other selection sets the exercise says to make. Save the file with a new name, being careful not to overwrite any of your other files.
Project Exercise 2: Creating a Multi Sub-Object Material
This exercise starts on page 337. It returns to the Material Editor.
- Open the Material Editor. Choose the first sample slot, as shown in the first illustration on page 338. Name the material. (This can be done before you edit a material or after you have done so.)
- Set the color value for the Diffuse color for this material as instructed. Note that the Color Selector has spinner buttons. If you want to change the value for a field that has a spinner button to zero, you can just right-click it. Click OK on the Color Selector window when you are done.
- Watch the color sample change as you modify the values for Specular Level (higher is shinier) and Glossiness (higher is a smaller highlight).
- Select the next sample slot, name it, and set its Diffuse color. Note that the text does not tell you what values to use for white. Pure white is attained by setting the red, green, and blue spinners each to 255. You may want to vary this a bit, to get a more realistic tone. Set the Specular Level and the Glossiness the same as the previous slot.
- Select the next sample slot, name it, and set the Diffuse color to black. Again, you may want to use a variant of black, instead of setting all color components to 0. Note that you are told to set the Specular Level to 50 and the Glossiness to 20.
Question 1: What is the general effect of setting the Specular Level to 50 instead of 90, and of setting the Glossiness to 20 instead of 80?
- To assign colors to selected polygons, you need to be in the polygon subobject mode. Enter that mode, then select the Wheel_Bolt selection set from the dropdown in the toolbar.
- The text tells you to use F2 to toggle between seeing the edges of selected polygons and seeing the selected polygons colored a solid red. The latter is actually useful when you want a quick overview of which polygons are selected. The former is useful when you want to see the material that you apply to the polygons.
- Open the Material Editor, and select the red material you made. You can drag and drop the material, but for a selection set it may be better to click the Assign Material to Selection button.
- Switch to the Wheel_White selection set, change to the white material in the Material Editor, and apply the material to the selected polygons.
- Switch to either the Wheel_Black selection set or the Wheel_Tire selection set. Apply the black material to it.
- Save incrementally. Notice something in the Material Editor: When you used it before, the material that was applied to the currently selected object had white triangles in the corners of its slot. All three materials have this at this time. This is because you have been selecting subobjects to apply the materials to. Each of these materials has been applied to portions of the same object, so the all show white corners when you have any of the subobjects in the wheel selected.
Project Exercise 3: Loading the MSO Material
This exercise starts on page 339. Continue working with the file you saved at the end of the exercise above.
- Open the Material Editor and select the next unused sample slot.
- Find and click the eyedropper button next to the material name field. Click anywhere on the wheel as instructed.
- Your screen may be different from the illustration at the bottom of page 339. You should see a Multi/Sub-Object Basic Parameters rollout, but it may have more materials in it than the example in the book. Mine has the three named materials, as well as three randomly numbered materials, indicating that there are at least three parts of the wheel that I have not applied a named material to at this time.
Name the MSO material as instructed and save the file again.
Project Exercise 4: Fine tuning the materials
The text continues with some modifications to the materials, using more resources from the student disk. After some discussion, the exercise begins on page 341. Continue with the file you saved in the previous exercise.
- Open the Material Editor. The text says to select the Wheel Bolt material. The author has forgotten that he told us to name it the Red Bolt material. Select that one.
- Open the Maps rollout and find the line for Reflection.
- Click the Map button for Reflection that currently says None.
- Click Bitmap in the list that appears, and click OK.
- Navigate to the Images folder for this project, and find the Rocket_Refmap_Blur.jpg file. Select it and click Open.
- Do a Quick Render of the Perspective viewport.
Let me make an observation here: in version 2010, the software no longer has a Quick Render function. The button that previously did the Quick Render function is called Render Production. It actually performs the function of the Render button in the Render Setup dialog box. This is handy if that is what you want, but it is unfortunate if you actually wanted to render the current state of the current viewport as one frame.
To perform what we used to call a Quick Render, you will need to:
Back to the lesson. The author has added a material that fakes a reflection of a scene in the surface of the bolt. You will see in the render window that the material is too reflective, just like the pool ball made earlier in the term.
- Open the Render Setup dialog
- Select Single to render one frame
- Deselect the checkbox for Files, if it has already been selected, otherwise you will overwrite any animation file you have already made, and not render to the screen.
- Click Render.
Not very quick any more, is it? Maybe I should tell you to "render one frame to check your work". Note that you will also have to change it back again to actually render to a file.
- Go back to the Maps rollout by clicking the Go to Parent button in the Material Editor's horizontal toolbar. Change the Reflection Amount value to 30. Render again to see the difference.
- The text says to carry out these step with the other two named materials, but to experiment with the value of Reflection Amount.
Question 2: What values look best to you for Reflection Amount, for each of the three materials?
- Save incrementally.
Project Exercise 5: Applying a bump map (and a surprise)
The text mentioned that the surface of the tire portion of the wheel should look rougher that the white and red portions. Adding a bump map will do that. This exercise begins on page 342.
- Continue with the scene file from the previous exercise. Open the Material Editor and select the black material. Open the Materials rollout.
- Find the Bump line, and click the Map button for it. (It should say None at this time.) This time, click Noise, then click OK.
- On the Parameters screen that appears, find the Size field and change the value to 0.02. After you have made this setting, click the Go to Parent button.
- Change the Bump Amount value to 60.
- Render the viewport again, and enjoy your work.
- Save incrementally, and read the instruction at the bottom of page 363.
The author offers two alternatives: repeat adding materials to the other three wheels in the scene, or clone this wheel 3 times, then move and rotate the copies into the space occupied by the other three wheels, finally deleting the wheels without materials.
(It should be clear to you now that objects in 3DS Max can intersect, and that they can even occupy the same space. You can change objects so that other objects cannot penetrate them, but that is another lesson.)
It would be a good idea to follow the second suggestion, using the Layer Manager to make objects visible as you need them.
- Make three copies of the wheel. Note their names, and move them to the side for now.
- Make one of the other original wheels visible. Note its name. Move/rotate one of the copies into exactly the same space occupied by the original you are replacing.
- Use the Select from Scene dialog box to select the wheel that is being replaced and delete it.
- Repeat steps b and c for each of the other two wheels.
- Save incrementally and show me a render of the scene.
Project Exercise 6: Fin base material
We will move ahead to page 345 in the text. The author brings up the point that a map image will not always fit the object you want it to fit. There is inadequate explanation of what you are doing in this chapter. For a more informative discussion of the subject, follow this link to a tutorial on the UVW Unwrap modifier. For those who don't want to follow the link, I will do what I can here.
Maps are colors, patterns, or other coverings that we put on the surfaces of objects. In this lesson, we will look briefly at tools to use the UVW coordinate system on maps.
In general, U, V, and W are just the three letters that come before X, Y, and Z in the English alphabet (and others). So what? Well, the letters correspond to an artificial coordinate set. If X, Y, and Z are the Cartesian coordinates of a 3D object, U, V, and W are the coordinates we would use to measure the surface of that object if we peeled the surface off and laid it out flat, like skinning an animal to make leather. As you might imagine, a flattened pattern for a complex object will have a very unusual appearance. As such, we will use some special tools in 3DS Max to manipulate maps for 3D objects.
3DS Max uses the UVW Map modifier to apply maps to objects more precisely. There are several map types that apply to classic object shapes:
- planar - for flat surfaces
- cylindrical - for cylinders, with or without flat ends. If the cylinder has flat ends, we can use the Cap option to apply a planar map to the ends.
- spherical - meant for spheres (ball-shaped objects). This one has a imitation we can overcome: the edges of a map will form a seam on one side of the sphere, and at the poles (points where the top edge meets itself, and where the bottom edge meets itself)
- box - a classic six-sided figure, that may or may not be a cube
This exercise begins on page 346.
- Open the file specified in this step. Save it with your name incorporated in the filename.
- Open the Material Editor. Select a sample slot, and set the Diffuse color for this slot to whatever shade of white you used for the wheels.
- Name the material as instructed. Drag and drop the material from the sample slot onto the fin.
- Se the Specular Level and the Glossiness for the material as instructed. Watch the fin change as you change each setting. (The text warns you that the material will look gray in a render window at this point, due to the lighting in the scene. It would have been nice to have mentioned it for the wheels. Lighting comes up in chapter 10.)
- Follow the instructions to add the same reflection map that you added to the wheels.
- Change the Reflection Amount to 35.
- Do a Quick Render to view the work so far. Modify the Reflection Amount, if you want to, then save incrementally. Continue to the next exercise.
Project Exercise 7: Adding the decal
This exercise begins on page 347.
- If it is closed, open the Material Editor. Select the Fin_Decal Material.
- Go to the Maps rollout, and click the map button for Diffuse Color. Click Bitmap, and OK. Navigate to the file specified in the text. (It does not match figure 7.79.) Select it and click Open.
- The map will not appear in a viewport until you click the Show Map in Viewport button. Do so, and note that it looks a lot like figure 7.81. Not very good, yet.
- The Coordinates rollout should be at the top of the rollouts section in Material Editor at this point. Look for the Angle column (the last one on the right).
- Find the W field in this column, and change the value to 90. If you use the spinner, you can watch it rotate as you increase the value.
- Change the values in the Tiling column as instructed. This changes the size of the decal. Then remove the checkmarks from the Tile column.
- Change the Offset values as instructed. This changes the placement of the decal on the fin. Almost there, but the text explains that the fin was originally a six sided box, so the map is being applied to the remains of all six sides. This takes us to the next exercise.
Project Exercise 8: Using a UVW modifier
This exercise begins on page 350.
- Change the coordinate values to the settings in the text. These are the original values, except for the Tile checkmarks.
- Close the Material Editor. In any viewport, select the fin, the open the Modifier List, and add a UVW Map modifier to it. Note that the Modifier Stack labels the modifier as UVW Mapping.
- Verify that you see the orange frame around the fin.
- Find the Alignment section of the modifier's parameters, and click the Bitmap Fit button.
- Navigate to the decal file again, select it, and click Open.
Adjusting the UVW Map Gizmo
- Click the plus sign for the UVW Mapping object in the Modifier stack. Select the Gizmo subobject.
- There is no instruction in this step.
- Click the Rotate tool, and ignore the rest of this instruction in the text: it makes no sense. Select the Left viewport, and rotate the decal until it looks like it is at the right angle. (Something like figure 7.87.)
- Select the Uniform Scale tool, and adjust the size of the decal so it fits on the fin, matching the images on page 352.
- Render the viewport you are working in, to see the progress.
Correcting the projection
- The text informs you that the decal looks fine on the left side of the fin, but the letters (and the image) appear reversed on the right side. Look in the Parameters rollout of the UVW Mapping modifier. Find the Mapping radio buttons, and change the mapping type from Planar to Box. (Planar would have worked well if this were a flag.)
- This takes us back to having the decal show on six faces of the fin. The fin is no longer meant to have six sides, so the author has a trick to make it work out.
- In the Mapping section of the Parameters rollout, find the Height parameter, and change its value to 0.01. (It is not allowed to be 0, so you make it a small value.)
- The value used makes the unwanted sides of the box very thin, so they won't be noticed.
The rest of the chapter repeats work you have seen already. It is good practice, but we should move on to another topic.