How do I make an Octagon

Hi,

Is it possible to make an octagon with one prim? What I am trying to make is an object thats 6m tall & 8m wide. The top & bottom needs to be flat and there should be 8 sides.

Thanks.

Unfortunately, no. IMO you should be able to just turn off smoothing on cylinders and specify the number of sides to accomplish this, but you can't. (If you approach a cylinder from a distance and see it rendering at a lower level of detail, you might notice that SL is doing this under the hood anyway.) Instead you have to build it out of multiple flat sided prims. If you search this forum for "octagon", I'm pretty sure you'll find instructions for making one with the fewest prims possible. I bet Chosen Few knows how to do it, so you might search on his name too.

Heh, thanks for the vote of confidence, Cadroe.

There are three possibilities for you, Iwanna. The simplest thing to do is to use 3 prims, configured like this:



If you really only want to use one prim, and you don't need the octagon to have any depth to it, then you might want to consider using a texture to fake it. Put an opaque octagon on a transparent background, and apply the image to the top of a cube. Then put a fully transparent texture on all the other sides (or to be more efficient, use the same octagon texture and offset it on the sides so that just the transparent part shows). End result, you'll have what appears to be an octagon, even though it's really a cube.

The third option, is you could make your octagon in a third party 3D modeling program and import it as a sculpted prim. If you're not familiar with sculpties, see http://wiki.secondlife.com/wiki/Sculpted_Prims for details. It's conceivable you could sculpt a one-prim octagon (although I've never tried), but there is a catch. Sctulpties only have 32x32 vertices, max, and an octagon has a lot of corners. When people view it from close up, all 16 corners could be nice and sharp, but from further away, it could start to look like a blob pretty quickly, as the LOD culling on sculpties is pretty severe.


Those are three options to play with. Me, I'd probably just use the first one and call it a day, but if you really, really need to use just one prim, try the others.

I can think of making it in three prims:

* Line up three cube prims
* Resize the outside two to <3.414,0.25,1>
* Resize the centre one to <3.414,1.414,0.25>
* Rotate outside two so positive z face is pointing away from centre prim (i.e. rotate them by +90 and -90 around the y-axis)
* Give outside two a taper of 0.4142
* Link them up and scale them to suit.

Edit: too slow.

Not really too slow, you added a nice carrot salad made out of the quare root of 2.
Very tasteful!

I have a full perms octagon made like Chosen's available as a freebie in my shop, along with some other cool shapes. Feel free to stop by Zebulon 175,75,27. Be warned it is a mature sim.

You can make an Octagon with a scupt prim.

You can see examples and download a program here http://kanae.net/secondlife/