How to build this?

I saw a swan can change the shape of its neck while swimming and looks like the real one. How to achieve it? Create a new prim while delete an old one, then create the old one and delete the new one? Or use LSL script? Or .. ? Thanks.

simple way is to have all possible prims always there and just make all prims invisible, except the prims for one "frame".

trickier way is to know how to shape and reposition prims of a linkset for a smooth movement transition, but that is usually not worth the efford as long as you have the prims free for the quick and simple way.

right klick the object to see all prims marked, including invisible ones.

animated sculpty map.

for more info on animating sculpt maps see:

http://wiki.secondlife.com/wiki/PRIM_TYPE_SCULPT

It's also been pointed out (and I've seen it myself) that there is a significant delay in frames between sculpt maps. So far I've been able to animate 4 sculpt maps using the examples given. Otherwise it sticks at Sculpt Type Sphere.

Hunter, If you include prims with sculptmaps testures on their faces (one per face for maximum texture/prim ratio) you won't get that ballooning going on. There no reason you sould be limited to 4 per anmation, I'm certainly not.

So are you saying Prims as in 'Objects' included in contents per face with a sculpt map on said face of Object?

Also where and how does this tie into frames. I've seen video of streamed sculpt maps on an object that morphed (animated)using http referenced sculpt maps from a server.

As far as the discussion on the wiki though the delay had not been resolved ( or I missed an update link).

I'll have a go at your suggestion though. I think sculpt map animation would be keen in the sense of efficiency of having multiple linked/textured/scripted objects = prim heavy with alpha call scripts VS. One prim with several sculptmaps for said prim to morph into = still, one object changed every so many seconds.

no, not in the contents, an inworld prim on which the sculptmaps are used as surface textures. This forces the veiwer to DL the maps locally where it can be utilized on demand of the script in your animated sculpt(which is a different prim with it's own surface texture). The ballooning is mearly the hiccup between the spped of the script and the speed of DLng the new sculptmap. If all the maps are continuously in the same veiwing frame as the sculpty, then there will be no latency hiccup and the animations will be smooth(once they've actually downloaded).