Part 1: Creating Primary Surfaces
 
 
 

In this section, you will use the Square, Skin, and Align tools to create the basic shape of the shower gel bottle.

You will build the front half of the bottle, which will later be mirrored to complete the design. You will create a smooth connection between both halves by controlling the implied tangent continuity across the center line.

When you create the shoulder surface, you will blend it smoothly to the main bottle surface using tangent continuity.

Watch Part 1 of the tutorial.

Opening the tutorial file

The tutorial file has curves for building the shower gel bottle.

  1. Choose File > Open to open the File Browser.
  2. In the File Browser, locate the CourseWare directory and set it as the Current Project.
  3. Open the file called showergel.wire, located in the wire directory in the CourseWare project.

    (For information on how to open a file, see Opening the tutorial file.)

  4. A dialog box appears, asking if you want to delete all objects, shaders, views, and actions. Click Yes.
  5. If your values for construction tolerances differ from those in the showergel.wire file, you will be presented with a dialog.

  6. Click Accept New Settings to use the construction tolerances in showergel.wire.

The file is opened.

The main bottle curves are visible and placed on a layer named Curves.

Other curves are on layers that are not currently visible; you will use these later in the tutorial.

Setting the Construction Tolerances

Before you start to create your model, you will choose the construction tolerances you want to work to.

  1. Choose Preferences > Construction Options .

    The Construction Preset is set to User Defined. While this is suitable for rapid concept development, a more accurate setting will be needed for data transfer to a CAD or Rapid Prototyping system.

  2. In the option window, choose General CAD Settings.

    To see what tolerances you will be working to, open the tolerances section of the Construction Options window.

    TipFor future projects, you can choose settings that match the CAD system you will be exporting data to.
  3. Close the Construction Options window.

Creating the Main Bottle Surface

You will start by creating the main bottle shape using a Square surface.

  1. Maximize the Perspective view.

  2. Check that the Bottle layer tab is shown in yellow, indicating the new surfaces you create will be assigned to it. If not, click the layer tab to make it active.

  3. Choose Surfaces > Boundary Surfaces > Square .
  4. Double-click the icon to open the option window.

    In the Square option window, the four boundaries of the square are listed.

    For boundaries, 2 and 4 change the continuity option to Fixed. This ensures that the square surface accurately matches the curves.

    For boundaries 1 and 3, change the Continuity option to Implied Tangent. The Implied Tangent option ensures the surfaces will align smoothly across the center line.

    You are prompted to select the four boundary curves. Click the curves in the order shown.

    When the fourth curve is selected the square surface is created.

Creating the Neck Surface

  1. Adjust the view to see the curves for the neck of the bottle.

  2. Choose Surfaces > Skin and, when prompted, select the two neck curves to create the neck surface.

  3. Now that you have built the main surfaces, turn off the Curves layer, leaving only the surfaces visible on the screen.

Creating the Shoulder Surface

The shoulder surface needs to blend smoothly from the main body surface.

First, you will create the shoulder as a simple skin surface from the body to the neck. You will then create continuity between the shoulder and body, using the Align tool.

It is useful to understand how the Align tool creates the desired continuity, and you can see this by observing how the CVs and Hulls change as the Align tool is applied.

Positional Continuity

One row of CVs is aligned to the other surface. This is the default continuity when you create the skin surface.

Tangent Continuity

Two rows of CVs are aligned to the other surface.

Curvature Continuity

Three rows of CVs are aligned to the other surface.

Creating the Shoulder Surface

First, create the shoulder surface with positional continuity.

  1. Choose the Surfaces > Skin tool.
  2. When prompted, select the edges of the body and neck surfaces to create the shoulder skin surface.

Aligning the Shoulder Surface

Now, you will use the Align tool to modify the shoulder surface, making it Tangent to the body surface.

First, delete the Construction History of the shoulder skin, to allow it to be modified.

  1. With the shoulder surface still selected, choose Delete > Delete Construction History and answer Yes when prompted.

  2. With the surface still selected, turn on the CVs by clicking the Cv/Hull check box on the Control Panel. This makes it easier to see the results of the Align tool.

  3. Choose Object Edit > Align > Align 2008 . Double-click the Align icon to open the option window. Set Continuity to Tangent.

    You are prompted to select the boundary of the surface to be aligned (the input). This is the skin surface you created for the shoulder.

  4. Move the cursor to the junction of the bottle and shoulder surfaces. Click the edge of the surface and select the skin surface from the pick chooser.

    The selected edge is highlighted and labeled as “Input”.

    You are prompted to select the object to align to (the master).

  5. Click on the boundary between the two surfaces again to select the edge of the body.

    The top edge of the body surface is automatically selected.

    The CVs of the shoulder surface are modified to align the shoulder to the bottle surface with tangent continuity, as indicated by the T on the green indicator.

  6. Turn on Tangent Balance. This adjusts the hull shape of the input surface to match that of the master. (Turn on the CVs and hulls on the master to see this).

  7. Scroll to the bottom of the option window and turn off Continuity Check to remove the continuity indicator.

    Now, you will modify the character of the shoulder blend by moving and scaling the CVs and Hulls.

  8. Use the F9 hotkey to show the four modelling windows.

  9. Choose Pick > Nothing to deselect the surface.
  10. Choose Pick > Point Types > Hull .
  11. In the Back window, select the hull of the second row of CVs from the top by clicking the red hull line.

  12. Choose Transform > Non-p Scale and drag with the to create a smooth shoulder shape.
    NoteThe pivot point for the CVs defaults to the origin, so the CVs will scale correctly.

  13. In the Left window, drag with the to refine the shoulder shape.

  14. With the click the hull of the third row of CVs and drag upwards to sharpen the shoulder profile.

    Continue to adjust the vertical position of the hulls until you are happy with the design.

  15. Choose Pick > Nothing to deselect the CVs.
  16. Turn off the CVs and hulls, using the Control Panel.
  17. Use diagnostic shading to evaluate the result.

    TipSet the Continuity option to Curvature in the Align tool to adjust the third row of CVs and get an even smoother transition.

Saving your work

Now you will save the scene as a new file.

  1. Save your work in the wire directory of the Lessons project.
  2. Name your file myshowergel.wire.

    For information on creating the Lessons project, or saving your work, see Saving your work in a Windows environment or Saving your work in a Mac OS X environment.