Flexible Paths: why only certain shapes?

hey folks. im new to building (that is, beginning to build more complex items) and was just wondering why the flexible path option is only available to certain shapes? it seems cylidners (and variations thereof) are the only ones that can flex. why is this?

i dont see why a cube or sphere shouldnt flex? i guess the reason is that im just tired of every flex object having to have either a pointy end, or a flat, cropped end. Smooth tips would be great.

is there something im missing? are there scripts to override this? or is this just an issue of "Too bad, thats the way it is and theres nothing you can do about it?"


thanks in advance!




>- Y

Cylinders, cubes, pyramids, and prisms can flex.

I'm a bit happy spheres can't flex, otherwise we'd be seeing more prim boobs on ladies (and misguided immature men of course) than hair. ;D

It's to do with the way the prims are generated. The flexible types, the cube, cylinder and prism, can be thought of as made by moving some shape (square, circle, triangle) along a straight line. Making the prim flexible means that straight line can become floppy. Spheres are something of a special case, and tori, tubes and rings are all made by moving the circle, square or triangle along a circular path. This is I assume a bit more involved to work out how it should flex, which is presumably why they haven't been done yet.

Cubes can flex.

But as to the reason, note the name of the option: Flexible Path

Boxes, Cylinders and Prisms are generated by extruding a 2D shape (square, circle [sorta] and triangle, respectively) along a straight path.

Tubes, Torii and Prisms are created by extruding those same shapes around a circular path. So a Torus is essentially just a cylinder wrapped around so that it's end faces touch. Spheres are similarly created, by extruding a half-circle shape around a circular path. If a Torus had a 0.5 B Profile Cut, and if a Y Hole Size of 1.0 were permitted, it would be virtually identical to a sphere, except that the normals of the verts meeting at the "poles" probably wouldn't unify, so it would look "pointy."

But anyhow, Flexible Path just permits the normally straight extrusion path to bend, according to the specified parameters and how the prim is moved around. So if something like this were done with a Tube, Torus, Prism or Sphere, how would you expect it to "flex"? Would, for example, the beginning of the path be fixed, allowing the other end to dangle freely? Well, that's essentially what we already have with the existing flex prim types, though it might permit you to specify a bit more "curl" to them, but they'd still have a flat end.

I've wondered if a feasible "flex" option for the circular extrusion types might be to divide the prim's verts into "zones" along the X axis (axis of revolution), and flex that axis, rather than the extrusion path, leaving the local -X end fixed (to be consistent with the straight-extruders' fixed local -Z end). That's probably an unintelligible description, so I'll try something a little more concrete:

Imagine a sphere, which has "latitude" and "longitude" lines. The "pole" running through the sphere is permitted to flex. The individual latitude planes remain perpendicular to the pole wherever they intersect it, and the longitudes between stretch to keep the latitudes connected. (see attachment)

But that's probably a horrendously CPU-intensive operation.

yes, that was exactly what i was thinking. however, i wasnt aware of the basic geometry with which SL creates its objects. i was thinking the exact thing: a sphere whose axis served as the path along which the rest of the object would follow and flex, the "north" end of the pole being the root, and the "south" pole being the flexing end.

oh well, maybe someday this will be possible as SL & technology increase. at least someone understood what i was getting at.

thanks for everyone's input!

: )

Actually, this wouldn't be all that difficult if spheres were created by extruding a circle along the "pole" and progressively scaling the circular cross section, instead of sweeping a half-circle around the pole. However, then a few options would behave differently. Dimple (if present) would probably leave flat ends instead of a conic section, twist would deform any path cuts along the pole (then again, twist as it is now is kinda strange anyway for pretty much anything but completely inverting the shell), and hollow wouldn't leave a constant-thickness "shell", but would thin to 0 at the poles.