Instructions for using primitive 3-D Modeling tool

Basic Tutorial

Starting the tool

1: Go into the directory in which the tool is located

2: Double click the executable labeled "TheProject.exe"

3 Windows should pop up:

1) An MS DOS prompt

2) A window labeled "Model Draw Window"

3) A window labeled "Jon's GLUI", with various controls on it

Drawing Points

First, here's the two ways to draw points:

1: Simply click the mouse on the draw window

Try clicking a few times at random on the window, a shape like this should appear:

The only way to specify the z-coordinate when using the mouse

is to use the '8' and '2' keys to change it – 8 changes the axis so the point is further away, 2 so it is closer.

2: Use the GLUI window to specify points:

In the GLUI X/Y/Z control boxes, enter the points 1.0, 1.0, -1.0

Notice how yellow lines and a red line have appeared in the draw window.

The Yellow lines in the center are the X and Y axis lines, and the one in the upper right is the Z axis line. They show the magnitude of how far in each direction the point will draw. The red line shows the exact point on the window the point will appear.

Now click the 'Draw Point' button - this will draw from the previously designated point to the point indicated by the red line.

Now, erase the points you just drew. The easiest way to do this is to just right click in the draw window. You will see the line you just drew with the GLUI controls disappear. The other way to erase a point is to click the 'erase point' button in the GLUI window.

Using either of these methods, erase all the points from the screen

Also, set the X/Y/Z coordinates in the GLUI window to 0

Now lets go over the different types of polygons you can use:

Triangles:

Click the 'Triangles' button on the GLUI window

As you might expect, this draws triangles, connecting the first point to the second, the second to the third, and the third to the first. After 3 points have been drawn, a new triangle is automatically started.

Triangle Strips:

Click the 'Triangle Strip' button just below the 'Triangles' button

These are a bit more complicated. Each new point creates a connection

from the newly clicked point and the previous two clicked points, and will

not begin a new polygon until either the 'n' key or the 'Start new polygon' button is pressed.

Experiment with drawing/erasing points with the triangle strip until you get the idea. Then, hit the 'n' key to start a new one, and experiment with that. When you are ready, continue to Quads.

Quads:

This command just draws four points in first-second, second-third, third-fourth, fourth-first order, much like triangles. Also like triangles, a new polygon is automatically started after four points have been drawn.

Quad Strips:

The most complicated of the polygons are quad strips. They are drawn as

follows:

first-second first-third

second-fourth

third-fourth

Also, unless enough points have been drawn, not all the points show (four

must be drawn for the first strip, and two for each strip after that).

Like triangle strips, 'n' or the new polygon button must be pressed for a new polygon to start.

Experiment until you are comfortable with quad strips.

Drawing a Cube

First, erase any points on the screen.

Now click the Quads button, as it is the easiest way to draw a cube

Enter in the following points into the X/Y/Z boxes, hitting the draw point after each set:

-1/-1/-1

-1/1/-1

1/1/-1

1/-1/-1

-1/-1/1

-1/1/1

1/1/1

1/-1/1

-1/-1/-1

-1/1/-1

-1/1/1

-1/-1/1

1/-1/-1

1/1/-1

1/1/1

1/-1/1

-1/1/-1

1/1/-1

1/1/1

-1/1/1

1/-1/-1

-1/-1/-1

-1/-1/1

1/-1/1

Saving Your Work

Whew, now that we've done all that, it’s a good time to save our work.

Type "box" into the file name text box, and press the "Save Current Model" button.

Just to demonstrate loading, press the quit button and reload the program.

Now, type "box" into the file name text box, and press the "load model from file" button. You should now be looking at your previously created cube:

Changing the Viewpoint

Now, lets look at it from a different angle. Click the "Draw/View Mode" checkbox.

This will alter the image to a better viewing point. However note that drawing with the mouse will be difficult, as the points you click will no longer be the point drawn on the screen.

You will also note a small sphere has appeared above the box. This is the light source for the scene, and affects coloring of the box (which we will add later).

To move the box around, just click and drag the transformation controls, which will change the boxes location on the screen. The rotation with rotate the cube.

Experiment with these controls a little while, then reset the translation, and move the rotation so you are looking at the cube from a diagonal position:

Now lets make is so you can see more than just the outline of the cube:

Click the wireframe checkbox. This checkbox switches between being able to only see the outline of the polygons, and having solid polygons:

Colors and Texture Mapping

Now lets play with polygon color:

Change the "Change current polygon" spinner until the nearest side is outlined in purple (it should be 1)

If the outline is difficult to see, increase the "polygon outline visibility" spinner, which will increase the thickness of the outline

Now spin the RGB spinners around, and see the polygon change color

Now click the "make polygon emissive" box. The color will change. This is because the light source (the little sphere) no longer affect the polygon color.

Now uncheck the "make polygon emissive" box, and move the sphere around by using the light controls. The color should change slightly as you move it around, allowing you to see the color when the light is at different angles.

The last thing for the basic tutorial is the texture mapping.

Select another of the visible polygons the same way you selecting this one.

Now spin the "texture number" spinner to either 0 or 1 (the only textures we currently have). The polygon with now change according the applied texture.

Finally, change the current polygon to the one with the color change, and give it a texture. Notice how the color of the texture changes along with the color of the polygon.

This concludes the basic tutorial; feel free to continue experimenting with more complex shapes.