Creating a Mug

Lee A Butler

Army Research Laboratory

Survivability/Lethality Analysis Directorate



    Aberdeen Proving Ground

    MD

    21005-5068

  

Eric W Edwards

SURVICE Engineering Company



    4695 Millennium Drive

    Belcamp

    MD

    21017-1505

  

Betty J Schueler

Quantum Research International, Inc.



    2014 Tollgate Rd, Suite 203

    Bel Air

    MD

    21014

  

Robert G Parker

Army Research Laboratory

Survivability/Lethality Analysis Directorate



    Aberdeen Proving Ground

    MD

    21005-5068

  

John R Anderson

Army Research Laboratory

Survivability/Lethality Analysis Directorate



    Aberdeen Proving Ground

    MD

    21005-5068

  

Approved for public release; distribution is unlimited


In this lesson, you will:

In this lesson, you will be continuing your work creating real-life objects-in this case, the basic body shape of a coffee mug. In the next lesson, you will refine the body so that it is more realistic.

1. Creating a New Database

Create a new database and call it mug.g. Go back to the File menu and select Preferences, then Units, and then inches. This will create your body using inches. (Note: You could also do this by typing units in at the Command Window prompt.)

2. Creating the Outside Cylinder Using the In Command

To begin making the body, you will need to create an outside right circular cylinder. At the MGED prompt, type: in bodyout.s rcc

The diagram of this command is as follows:

inbodyout.srcc
Make a shapeCall it bodyout.sThe shape type is right circular cylinder

MGED will ask you the following questions about the cylinder you want to make. Type in the values given in bold. Make sure you leave spaces between variable values. Enter X, Y, Z of vertex: 0 0 0[Enter] Enter X, Y, Z of height (H) vector: 0 0 3.5[Enter] Enter radius: 1.75[Enter]

Note that the streamlined way to do this would be to type: in bodyout.s rcc 0 0 0 0 0 3.5 1.75[Enter]

The diagram of this command is as follows:

inbodyout.srcc0 0 00 0 3.51.75
Make a shapeCall it bodyout.sThe shape type is right circular cylinderThe x, y, and z of vertex is 0 0 0The x, y, and z of the height vector is 0 0 3.5The radius is 1.75

A shape of a cylinder, in wireframe form, will appear in the Graphics Window.

3. Creating the Inside Cylinder

Using this same method, type in the information for the inside right circular cylinder. This cylinder will be used to hollow out the outside cylinder. Whenever you are creating a hole in the surface of an object, make sure the shape creating the hole protrudes through the surface. This will ensure that you don't inadvertently leave a thin film of material where the two surfaces meet. in bodyin.s rcc 0 0 0.25 0 0 3.5 1.5[Enter]

The diagram of this command is:

inbodyin.srcc0 0 0.250 0 3.51.5
Make a shapeCall it bodyin.sThe shape type is right circular cylinderThe x, y, and z of vertex is 0, 0, and 0.25The x, y, and z of the height vector is 0, 0, and 3.5The radius is 1.5

A second cylinder, inside the first cylinder, should now appear in the Graphics Window.

4. Creating the Handle

Now you will want to enter some information about the body's handle. The shape type for the handle is an elliptical torus. At the Command Window prompt, type: in handle.s eto 0 2.5 1.75 1 0 0[Enter]

The diagram of this command is:

inhandle.seto0 2.5 1.751 0 0
Make a shapeName it handle.sThe shape type is elliptical torusThe x, y, and z of the vertex is 0, 2.5, and 1.75The x, y, and z of the normal vector is 1, 0, and 0

The program will ask you to enter more values for the elliptical torus you are creating. Type in the values shown in bold. Enter radius of revolution, r: 1.45[Enter] Enter X, Y, Z, of vector C: 0.6 0 0[Enter] Enter elliptical semi-minor axis, d: 0.2[Enter]

A doughnut shape should appear on the right-hand side of the body. If you look carefully, you can see that about one-third of the elliptical torus intersects the body.

5. Creating the Bodyout.s-Bodyin.s Combination

The next step is to combine the two cylinders into the body of the mug. To do this, type: comb body.c u bodyout.s - bodyin.s[Enter]

You have told the program to make the combination body.c out of the union of bodyout.s minus bodyin.s.

combbody.cubodyout.s-bodyin.s
Make a combinationCall it body.cCreate a union ofbodyout.s cylinderand subtractbodyin.s cylinder

6. Creating the Handle.s - Bodyout.s Combination

To combine the handle with the outside cylinder, type: comb handle.c u handle.s - bodyout.s[Enter]

combhandle.cuhandle.s-bodyout.s
Make a combinationCall it handle.cCreate a union ofthe handle.s torusand subtractthe bodyout.s cylinder

7. Creating the Region Mug.r

The last step, of this part of making the mug is to make a region out of your combinations. Type: r mug.r u body.c u handle.c[Enter]

rmug.rubody.cuhandle.c
Make a region of shapes of the same material and colorCall it mug.rCreate a union ofthe body.c combinationand merge it withthe handle.c combination

If you did this correctly, the program should say something similar to:



   Defaulting item number to 1002



   Creating region id=1001, air=0, GIFTmaterial=1, los=100

      

Wireframe Mug

You should now have the region mug.r that is a combination of shapes containing the same material and color. You could assign color and material at this point, but you will want to do some more work on this design to make it more realistic. So, for now, review the lessons of this chapter. When you are ready to work again, you can continue refining your design in the next lesson.

8. Review

In this lesson you:

  • Created an outside cylinder using the in command.

  • Created an inside cylinder for hollowing out the larger shape cylinder.

  • Created a handle for your mug.

  • Created a combination to produce the body of your mug.

  • Created a combination to join the handle to the body.

  • Created a region of combined shapes with the same material and color.