CAP 202 - Computer Animation II

Lesson 17 - Materials and Mapping Lab


This lesson uses materials and textures with the underwater scene from last term. Objectives important to this lesson:

  1. UVW maps and objects
  2. the UVW map gizmo
  3. Standard materials
  4. Blend materials
  5. using map channels
  6. projecting an image

The text jumps into an exercise based on lesson 9 (which we covered in CAP 201). It applies information from the last two chapters to that underwater scene.

Exercise Notes and Questions

Work through the exercises and turn in your answers to all questions below as part of the homework for this assignment.

Exercise 1: Open the author's version of the underwater scene as instructed. Ignore the yellow structures on the scene for now.
In step 7, you will find the Sand_01.jpg file in the same folder as the source file. Open it to bring it into the materials editor.

In step 11, add the UVW modifier as instructed. As you do, note the change in the appearance of the ocean floor. You should be able to see a difference between the color and texture of the ocean floor and that of the rocks, more pronounced than a moment ago.

In step 12, I could not follow the instruction at first. In 3DS Max 2009, the Real-World Map size option is on by default. Note that it is unchecked in the illustration for this step in the text. If yours is on, turn it off before trying to set the indicated values.
This step also shows a quick example of what happens when you use a map that is not designed to be tiled. Note the lines in the picture at the top of page 491, and the lack of lines, the smooth transition from one tile to another in the second picture. A map that will be tiled should flow visually from one repetition of itself to another, leaving the impression that there are no tiles.

In step 13, you are told to render the scene. After you do, turn on the Real-World Map size option and render again. This should produce a more appealing scene. Save the file with a new name, to avoid overwriting the next file you are told to open.

Cap202, lesson 17, materialsExercise 2: Whether you open the author's file or continue with your own, turn off the Real-World Map size option, if it is on.

The steps are not confusing until step 7. See the image on the right. You will now have two materials. The first one has a name, the second one does not. Because the second material has no name, 3DS Max calls it by the first available number, which is 1. So, confusingly, Material 1 is called SAND_01, and Material 2 is called Material #1. In step 7, click the Material 2 button that says Material #1.
Question 1: What is the command that leads to your being able to use two materials together?
At step 18, you begin the process of using a mask. Save incrementally at the end of this step, but continue into exercise 3 to finish this process.

Exercise 3: This exercise continues the last one, but it starts out with different tools.
In step 4, the Vertex Channel Display property was already turned on in 3DS Max 2009. If it is not active on your workstation, turn it on.

Step 6
gives you a new tool on the screen, based on a new modifier: the Vertex Paint panel.
In steps 7 and 8, choose the Paintbrush tool, and set its size as instructed.
Step 9
gives us a new term. The paintbrush is described as "a crossed circle with a perpendicular line showing the surface normal". (See the image on the right.) Think of the surface normal as the direction the slope of the surface is facing. In other words, the perpendicular line points in the direction from which an observer would see that point of the surface as flat.

In step 10, you paint on the slopes of the ocean floor. You are not expected to see the actual result until you render the scene in step 11.

A better result is obtained in step 13, when you swap the rock and sand elements of the blend.
However, I still did not see the rock elements in the render window until I went back to the UVW Mapping modifier and turned on the Real-World Map size option. In the images below, the Real-World option is turned on only for the render on the right. There is no other difference between the two scenes.

Without Real-World With Real-World
RenderWithoutReal RenderWithReal

Question 2: Try this, and note the warning you get before you are allowed to access the UVW Mapping modifier properties.

Exercise 4: Half way through. In this exercise, the first error is that you cannot do this one by continuing from the last save. You must open the author's version of the file for this exercise, or you will not have the required material available in the material editor.
We are reminded of several hot keys in this exercise.
Question 3: What did each of these hot keys do?

  • Alt-Q
  • P
  • Z
  • M

In step 10 we learn that the map for the rocks is a blend, and that a blend can only show one of the two materials at in a viewport. In the remaining steps, correct a problem with the map and the rocks by using a UVW Map with each rock.

The text turns to the Unwrap UVW modifier, which presents a 2D view of the surfaces of an object. Some theory about creating a custom map is discussed. The text advises us that we don't want to stretch or warp the map. We want, instead, to make a map that fits the polygons of the object it is for. In the next exercise you will unwrap a surface, move polygons on a map (changing what part of the map is applied to them), and size them to fit the map better.

Exercise 5: This exercise saves you some time. Load the indicated file. The changes to a few rocks are now applied to all of them.
Follow the instructions to select all the big rocks at once, apply a modifier to all of them, configure the modifier, and apply the rock material.

Exercise 6: As you will have noticed already, the author applied some lights to this scene before we began. We learn a new meaning for a word in the introduction to this exercise: caustic means several things, among them a pool of light that has passed through water. In this exercise, we will make use of some light.
Add a new material to the editor, as instructed in steps 1 through 7.
Configure the settings for the material in steps 8 through 10.
In steps 11 through 14, apply the material to each of four lights in the scene.

In steps 15 and 16 we take a trip to the Rendering menu (not the buttons) to access the Environment and Effects dialog. Turn on the Caustic effect you have added as instructed.
Render as instructed. Give it time. The render will slow down as it reaches the rocks.