Creating the Blend Surface

The label surface is recessed back from the main bottle surface. The gap between the two surfaces will be bridged by a Birail surface, which will give the label area its character.

To create the Birail, you will use the two trimmed edges as Rails, and create two new curves for the Generation curves.

Watch Part 4 of the tutorial.

Opening the tutorial file (optional)

If you successfully completed Part 3, proceed to the next step: Creating the Generation Curves below.

If you were not successful in part 3, open the file called showergel_part4.wire, located in the wire directory of the CourseWare project. This file contains the completed model from Part 3.

Creating the Generation Curves

Previously, you used the Align tool to create tangent continuity between two surfaces. Now, you will use the Align tool to create a tangent relationship between a curve and the edge of a surface.

To keep the Birail surface smooth and taut, you will use a curve with only 3 CVs to define the character of the blend. Two CVs will control tangent continuity to the label surface, and the third will control positional continuity to the body surface.

1. Zoom in to the area at the top of the label.
2. Choose Curves > New Curves > New Edit Point Curve .

3. Double-click to open the option window. In the Curve Degree section choose 2. This will create a single-span curve with only 3 CV points.

   

4. Use ( + (Windows) or + (Mac) keys together) and click the edge of the body surface. Then, without releasing the mouse button, drag to the bottom of the edge until the blue cross turns to a yellow one, confirming that you have accurately reached the corner of the surface.

   

   

   The first edit point of the new curve is placed.

5. Use again and click the edge of the label surface, then without releasing the mouse button, drag to the top of the edge.

   

   

   NoteThe Birail tool requires that all boundaries are accurately aligned, so it is important that the curve is snapped accurately to the corner.
6. Choose the Object Edit > Align > Align tool. Double-click the icon to open the option window.

   In the Continuity section, choose Tangent.

   

7. You are prompted to select the object to align (input). Click the curve, near the label surface.

   

8. You are prompted to select the object to align to.

   Click the vertical edge of the label surface, near the curve.

   

   The curve is adjusted to be tangent to the surface.

9. Adjust the view so you can see the lower part of the label surface.

   

10. Create another Degree 2 edit point curve across the gap, using curve snap to place the curve edit points exactly at the corner of the surfaces.

    

11. Use Object Edit > Align > Align again to align the curve to the label surface.

    

12. Zoom out to see the whole label area.

Building a Birail Surface with Continuity

1. Choose the Surfaces > Swept Surfaces > Rail Surface tool. Double-click the icon to open the option window.
2. Check that the options are set for 2 generation curves and 2 rail curves. Adjust the Continuity settings to:

   gen 1	Implied Tangent
   gen 2	Implied Tangent
   rail 1	Tangent
   rail 2	Position

   

3. Because the Rails will be the trimmed edges of surfaces, choosing the Rebld option on the two rails will improve the quality of the surface.

   

4. You are prompted to select the curves in order. Choose the curves and edges as shown.

   

   The Birail surface is created.

   

5. Choose Pick > Nothing to de-select the surface.
6. Choose Pick > Object , then pick and assign the two curves you created to the Curves layer.
7. Use diagnostic shading to evaluate the result.

   

Completing the Model with Round Surfaces

To complete the model, you will soften all the sharp edges with Round surfaces.

1. Remove the diagnostic shading from the model.

   

2. Zoom in to the neck area.
3. Choose the Surfaces > Round tool. Click the edge between the neck and the shoulder surfaces.

   

4. The default radius value is shown, and highlighted in white.

5. Type in a new radius value of 1. Then, press (Windows) or (Mac).

   

6. Click the Build button. A round fillet is created.
7. Choose Pick > Nothing to remove the round indicators.

   

8. Adjust the view to look at the edge of the label panel.
9. Use the Surfaces > Round tool again to create a fillet along the sharp edge of the label birail surface.

   

10. Choose Pick > Nothing to remove the round indicators.

    

11. Adjust the view to look at the base of the bottle.
12. Use the Surfaces > Round tool again to create a fillet.

    As there are two edges at the base, click first on main bottle surface edge.

    

    Type in a Radius value of 10. Then, click the edge created by the finger grip surface and the base. The round surface will then be built along both edges.

    

13. Click the Build button to create the round surface.

    

14. Choose Pick > Nothing to remove the round indicators.

    

15. Make sure that all the new surfaces are assigned to the Bottle layer.

    

16. Adjust the view and use the diagnostic shading to evaluate the rounds.

Save your work

1. Save your work in the wire directory of the Lessons project.
2. Name your file myshowergel4.wire.