Extrude Along Path AND Revolve with Rail

[Waldo]

I would like to extrude a profile along a path and also rotate that profile about a rail as it extrudes. The path is a 3D curve. The profile begins perpendicular to the path at one end and stays perpendicular to the path, but yet revolves around an axis at the same time. Kind of like mixing the commands Extrude Along a Path and Revolve with Rail. Is this possible???

[taoist]

Can you show an image of what you are talking about?

Are you talking about twisting the rail along its length like wringing out a towel?

Also,

would you post or put in your signature what version VW you are using and on what platform.

It will help to answer.

taoist

[Benson Shaw]

Hi, Waldo - Lofts could do this. Is your path same object as the rail, so the profile is revolving around the path as it extrudes? Or is the rail a different object?

If path and rail are same, then one way is to make the EAP, use the split tool to section it in several places on normal planes, extract & compose the section curves, rotate each as necessary, then loft them in sequence.

Another way is to orient several instances of your profile in 3 space and loft them in sequence. Profile can have a 3d locus or crosslines to indicate rotation center . Duplicate Along Path might be a start to place your profile instances along the path. Then rotate each one in its plane. This means establishing a working plane at each profile.

Try this first with a simple 3d profile on a straight path (say the z axis). Raise and rotate each of the profiles then use the Loft Surface tool in Loft No Rail mode. Click each one in sequence, then click the green checkmark or press return.

There may be some other ways, too. Maybe a bi rail loft? Kinda depends on your shapes and required rotation.

HTH

-B

[Kaare Baekgaard]

If the profile has distinct corners, you may also consider this: Create the path to be extruded along. Use that path to create a helix spiral with start & finish radius to match a corner. Duplicate and enter a rotation value + adjust radii to match an oposite distinct corner. Ungroup both helix spirals to turn them into nurbs curves. Place the profile perpendicular to the helixes at one end. Then extrude along both paths.

[Waldo]

Attached drawing describing what I am trying to do.

[Benson Shaw]

Here is my take with one way point on the middle plane to make a loft.

VW2011 and VW2008

Rotated all objects in top/plan to make plane of path horizontal - easier for me to visualize.

Duplicated Design Layer 1 and worked on Layer 2

Top/plan>drew a rectangle>Center on end of path>Convert to NURBS

Duplicate Along Path to make 5 dupes of the rectangle. These give working planes

Converted profile to NURBS curve

Duplicated and aligned to mid plane, oriented on plane (lots of mucking about)

Same for end plane

Loft Surface the 3 profiles in No Rail Mode.

Additional profiles on intermediate planes might constrain the loft better.

Post back if not working for you.

-B

[Waldo]

Benson, thanks much for the idea of using the Loft command. I spent all day on this yesterday (hopefully the boss isn't too upset). I ended up doing something very similar to what you suggested in your last post. I am new to 3D in Vectorworks, so I am having to learn as I go.

Thanks to all for the suggestions.

I am glad this Vectorworks Community Board is in existence.

A