Reference Curves

Objective: Learn how to lay out the reference curves that will drive the channels, the gemstones and the clasp.

Offset Curve On Surface

Go to the “Curve” tab and click on the “Offset Curve On Surface” command. Select one of the top edges of the solid.

Hover over the selection options to make sure the direction is the correct one, then type 1 in the command bar and press Enter. The curve is created 1 millimeter away.

Move the Curve to a User Layer

Click on the corresponding arrow to move the curve to one of the user layers. Select that same layer as the working layer so the curves you create next are born directly in it.

Diagonal Line

Click on the “Line” command.

From the front view, type 0 to set the center as the start point.

Then draw a diagonal line that starts 2 mm from the bottom of the solid and 8 mm from the Z axis. With grid snap on, this is simply moving up three squares.

Project the Line

Use the “Project” command to project that line onto the solid. Restore all views to check the projections.

You can now delete the original line, and from the perspective view also delete the rectangle you created earlier.

Whenever you need it, use pan, zoom and rotate, followed by Zoom Extents All, to center the elements in every viewport.

Copy the Top Circle

Select the top circle and, while holding Alt, click on the gumball arrow to create a copy at 0.75 mm. Move the copy to the reference curves layer.

Mirror

Go to the “Transform” tab and use the “Mirror” command.

• Type 0 to set the center.
• Hold Shift and click on the right side of the viewport.

You now have two more reference curves.

Perpendicular Line and Inner Offsets

Return to the “Curve” tab and create a line from the top line.

Use the front view to keep it perpendicular — in the perspective view perpendicularity is much harder to control.

Then use the “Offset Curve On Surface” command again:

• Select the solid’s edge, making sure the direction points inward.

• Type 0.5 mm and press Enter.
• Repeat the process with the bottom edge.

The model fills up with reference curves, but they are exactly what makes the rest of the process easy.

Video Lesson

Next Step

With the curves in place, we’ll carve the channels using Push and Pull.