Ruby script to rotate a shape using a arc

[wsellers89]

Sorry to ask such an elementary question, and I hope that this is the right forum. I am working my way through ruby scripting and wanted to rotate a simple surface such as a rectangle to form half a cylinder. It is extremely important that the edges of the cylinder match up with the x-axis, so I used an arc going from 0 to 90 degrees. When the script rotates the rectangle it does something strange in that it appears to over rotate (look near the origin). The script is as follows:

# Access the Entities object
model = Sketchup.active_model
ents = model.entities

# Create the 2-D shape
curve = ents.add_curve [5, 0, 0], [15, 0, 0],
[15, 0, 10], [5, 0, 10], [5, 0, 0]
curve_face = ents.add_face curve

# Create the arc path
path = ents.add_arc [0, 0, 0], [0, 0, 1], [1, 0, 0], 5, 0.0, 180.degrees

# Create the figure
curve_face.followme path

and I will attach an image of what resulted. I do know that if I draw a rectangle on the x-axis and intersect with the rotated object it does line up, but why the strange behavior? Am I missing something simple?

Sincerely,
Bill

---

[TIG]

Followme needs careful configuration to make a proper form...
Why not make the face arc + two radii and pushpull it?

[wsellers89]

Dear TIG,

Because what I was ultimately heading toward was the ability to take a complicated profile (Versus a rectangle) and rotate it exactly 180 degrees. The profile could be something like a cross section of a rocket launcher or a cross section of a jet engine, which wouldn't work well with the Push/Pull.

[TIG]

Followme for such fixed rotations like this will often fail and the resulting form won't be 'square' as desired - however, see my ExtrudeEdgesByLathe tool [in Extrusion Tools zip] - It takes the profile from a face etc and sweeps it properly through a given [picked or typed in] angle: it's probably too complex for your needs... BUT it can give you lots of clues for making a proper 45/90/180/270/360/etc swept form...

[wsellers89]

Wow! Thanks for the help and the education regarding what it takes to make it rotate a precise number of degrees. It was way past my skill level!

Thank you again.

Sincerely,
Bill