3D Modeling for Newbies Lesson 4 Two Rail Sweep in Aspire

Overview

This lesson continues exploring the Two-Rail Sweep tool in Vectric Aspire. It demonstrates how to modify an existing 3D component, create a wavy flag with controlled transitions, use multiple cross-sections along rails, and build a Viking ship hull by morphing profiles along the rails.

Steps

1. Modifying an Existing Model from the Clipart Library

1. Open a new session and insert clipart from the Component Library.
2. Draw vectors to separate part of the model, e.g. the stem from the flower.
3. Select the component and the vector, then use Cut to split it into two components.
4. Use the Measure Tool → Model Cross-Section to drag across the area you want to convert to a vector.
5. Minimize the number of nodes in the resulting vector for a cleaner result.
6. Use the Spiral Gadget to generate a spiral vector; download it from the Vectric website if not installed.
7. Position and copy the spiral vectors to create the new stem shape.
8. Select the new spiral vectors as the Rails, choose the existing cross-section as the Profile, and click Apply.

2. Making a Wavy Flag

1. Create vectors for the flag outline and wave profiles.
2. Ensure the wavy profile does not dip below the start/end nodes of the rail vectors, or holes will appear in the model.
3. Draw two rails running in the same direction, extending beyond the intended flag size.
4. Select both rails, select the wave profile, and click Apply.
5. Trim the resulting component using the flag-shaped vector:
   • Select the flag vector.
   • Hold Shift and click the component.
   • Keep or delete the unwanted parts.
6. For visual checking only, add stars and stripes as separate components. In production, use V-carving for stars and pocketing for stripes.

3. Creating a Flag with Different Wave Profiles at Top and Bottom

1. Create the first wavy profile for the top of the flag and a second profile for the bottom.
2. Delete the initial component if needed.
3. Select both rails as before.
4. Click the first profile and apply it to the start/top of the rails.
5. Click the second profile and attach it to the end/bottom of the rails.
6. The two-rail sweep will transition smoothly from one wave shape to the other.

4. Controlling Cross-Section Width / Z Height

• With Scale Cross-Section Width checked, the profile distorts where rails are farther apart: the Z height becomes taller.
• When unchecked, the profile keeps an even Z height across the rails.
• Adding extra intermediate profiles helps control distortion when morphing shapes along the rails.

5. Building the Viking Ship Hull

1. Draw two rails representing the boat from bow to stern.
2. Create multiple hull cross-section profiles: thin at the ends, thick at the center.
3. Select both rails.
4. Place the smaller/thinner profile at the beginning of the rails.
5. Place the larger profile at the center, where the hull is thickest.
6. Place another smaller profile near the tail/end.
7. Adjust starting/ending points so the profiles are aligned across from each other.
8. Click Apply.
9. Name the component to identify it as part of the boat.
10. Add mast, ropes, and flag separately using simple two-rail sweeps or closed-vector components.

Key Points / Warnings

• Use the Model Cross-Section tool carefully and choose vectors with the fewest nodes possible for best quality.
• For flags, the wave profile must not go below the start/end nodes of the rails or holes will appear in the surface.
• The Spiral Gadget may need to be downloaded separately from the Vectric website.
• Scale Cross-Section Width changes both width and Z height when rails diverge; keep it unchecked if you need a uniform Z height.
• Multiple profiles placed along the rails allow smooth transitions and reduce unwanted distortion.
• Cut/trim operations require selecting the vector, holding Shift, and selecting the component.
• Two-rail sweeps are built part-by-part; complex objects like a Viking ship are easier if you break them into separate components.