Problems with sculpted prims on Preview Grid

Hello people,

So I made a nonsensical NURB and got it ready for upload into SL. In fact, it did upload into SL, and even the next step was carried out successfully: I applied the image to a sculpted prim, and it changed shape accordingly. But then....it changed back into a sphere! Tried this a few times with new texture images, and every time the same happened: the prim changed shape, and then changed back to a sphere. Anyone got a solution for that?

Incidentally: Voice chat was on, at the Preview Grid, and without having opted for it I was in the middle of it. I didn't like it at all. How do you guys feel about it? I wonder how many people want the voice, and how many don't?

I can't really help you with your problem since I haven't had time to play with sculpties yet (but I'll be posting a guide here as soon as I have), but I did want to point one thing out, terminology wise, if I may. I'm not sure if your use of "NURB" was a typo our not, but just so no one's confused, there's no such thing as "a NURB". "NURBS" is not the plural of "NURB". NURBS is an acronym, which stands for non-uniform rational B-spline (the B is short for ether "basis" or "Bezier", depending on whom you ask). Removing the S doesn't make it singular; it cuts out the most important part of the whole thing, the spline.

Sorry if that sounds at all nitpicky, but I really don't want this forum to suffer the kind of terminology confusion that used to be so rampant on the texturing forum. Over there, people routinely used to interchange the words "layer" and "channel", which was really confusing for new people trying to learn graphics for the first time. I'd really hate for the same thing to happen here, whether it's concerning NURBS or anything else. People have enough to be confused about; wording shouldn't be one of them.

For anyone who's interested, to put "non-uniform rational B-splines" into plain simple English, it's a fancy way of saying "curves". In 3D modeling, NURBS surfaces are interpolated from curves, as opposed to polygonal surfaces, which are constructed from points and edges. For anyone coming from a 2D background, you can think of NURBS surfaces sort of like the 3D counterparts of 2D vector objects. Polygonal surfaces behave more like rasters in that they require definitive knowledge of every single point in order to exist, while NURBS surfaces are similar to vectors in that they're created dynamically by mathematical interpolations from relatively small numbers of control points.

Anyone good & confused? Well, in that case, just ignore the above paragraph and remember the following: NURBS = curvy surfaces; curvy surfaces = happy sculptie prims. That's really all you need to know.

Anyway to get back to the beginning, the right way to phrase it would be "I made a NURBS surface" or "I made a NURBS model", not "I made a NURB". There's no such thing as "a NURB".

Yes - I did actually know that. It was a sort of shorthand - a term of endearment, if you will. Don't feel like using the long version all the time. Nevertheless, you are probably right in wanting to keep terminology clear.

I had that 'snap back to a sphere' happen to me on some of the sculpt textures I uploaded, and I saw it on some other objects in the sandbox sims too. I saw this when the viewer got 'too close' to the prim. Too close varied based on which piece I was observing this on.

My guess: You'll see the sphere if the prim you're trying to produce is too complex for the viewer to render. If the texture is really messy, it'll always be a sphere. For a 'better' texture, the prim shows the sculpt shape at lower detail levels, but eventually you can cross a detail level where the resulting prim cannot be generated.

For my prim it would switch to a sphere within 1m of it, another prim I saw switched to a sphere if I got within ~20m (not sure exactly where the LOD boundaries are).

So, since you started with a 'nonsensical' design... that's probably what happened, SL didn't know how to draw that shape.

Are you on a Mac? I believe that's a known issue that they do that on Macs. I know it happens to me.

AMD, Nvidia, XP.

I just wanted to make sure that you have also seen the discussion on sculpted prims in the talk section of the wiki at: http://wiki.secondlife.com/wiki/Talk:Sculpted_Prims. If you haven't seen the wiki yet, by all means, check it out and contribute.

Good to have you aboard, Heretic! Welcome!

Thank you Ziggy, Wynx, Heretic. Wynx: No, I'm not on a Mac.
What Ziggy says makes good sense, though.