fur with shells and fins

[Tadao2289]

can someone explain to me how shells and fins work?? is it just a bunch of planes with an alpha texture? i really dont get it :(

[Buzzy]

Fins are usually used for long "Hairy" hair where you don't need alot of dimensionality
Shells are used for short "Furry" hair because it gives it a more full, 3d look

[Beartastic]

Good diagrams!

Also, fins are generally positioned wholly by hand; shells have the base shapes positioned by hand but then the extra layers can be handled by the vertex shader, which makes the whole thing much faster because you're not pushing as many verts through.

[Buzzy]

which makes the whole thing much faster because you're not pushing as many verts through.

Not entirely true. The savings would be minimal. Even if the verts are added by the vertex shader, it still has to draw them. So it will still have the same number of verts and pixels to draw.

[Beartastic]

Sorry, what I should have said is 'it's not as bad as it looks, all those polys." If you're fill-rate bound you're still going to be, but you save a decent slab of time (especially for characters) by doing the shell after you've done the skinning and other transforms.

But I'll defer to you because I'm nowhere near a lead tech yet :)

[Buzzy]

Yes, very good point. By modelling the shells yourself, you'd have to deal with them in the model which would be a huge pain. And actually, the skinning of all those extra verts would eat into render time.