Animating Fish Fins - Which Method?

[christian-docksey]

Hello everyone!

I'm at a stae where I've modelled some fish (mainly fishtank - decorative fish) and I'm stuck at finding a way to get that sway effect on the fins. When fish are still, they still lap the side fins and there is a bending and swaying movement on many of the other fins.... especially the tail fin. I've tried using sotbodies, Hair (dynamic curve) and cloth but none give me useable results. Maybe doing somethin wrong, but if someone could tell me a proven technique (say as in Nemo ... , or as in the comercials of Gil and Oscar by Flatboy productions....posted here by Admin), then I could concentrate on it. I have little time to solve the problem.

Thanks very much in advance...

[failure]

A couple of intelligently positioned sine deformers with dropoffs would do the trick. You can combine them with spline ik joint chains for more articulate movement if needed.

[christian-docksey]

Hmmm yeah ... I tried that to start with.... and I just tried it again, but it affects the whole mesh (The fin is a separate object to the body of the fish). The dropoff affects along the the sine wave direction (which I have placed horizontallyclose to the fin edge), but I can't dropoff the effect towards the base of the fin. I don't see there is a way to paint the weights of the deformer which would be ideal! I tried deselecting the base vertices of the fin with the set membership tool, but then the vertices just above those have the full effect, which is too abrupt. If I could get a smooth transition of the sine deformer effect from top to bottom, that would do it....but how?

Thanks a lot!!

[failure]

You can dropoff the effect toward whatever you want, just position the deformer manipulator.

If you want to control weighting assign deformer to the curve that controls spline ik chain and paint the joint weights.

[christian-docksey]

QUOTE(failure @ 12/28/05, 11:20 AM)
You can dropoff the effect toward whatever you want, just position the deformer manipulator.

If you want to control weighting assign deformer to the curve that controls spline ik chain and paint the joint weights.
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Thanks failure for your reply..... But on the first part of your answer, I can't see how you can make the dropoff go in a different direction.... I must be missing something, but there are no x,y,z options for that at all..... also, in the connection editor I don't see how I could connect in one axis only... ... When I move or scale the sine, I don't see any effect on the deformation (unless it is along the long axis of the handle, but that is along the length of the fin... which I don't have trouble with). I need to smooth the effect from the top tip of, say, the Dorsal fin, towards the lower edge of the fin which should appear stuck to the body (they are separate objects).

I know that you know how to do it.., but I can't get to follow your explanation. If you could go into a bit more detail , it would be great.... I really appreciate your effort ...

Thank you very much

[failure]

here is a very simple example. Sine with dropoff is just positioned in a way that it doesn't affect the base.

If fins are too complex for this you can use low-res nurbs surface or lattice to drive the hires mesh and deform that with a sine. Now excluding some control points from sine deformer set would work ok since, because of the large distance, deformation will blend nicely between two control points of the driving geo.

There are of course dozens of other ways to do it. Depends on actual model, needed detail and realism etc...

[failure]

Ok and here is na example with dense mesh driven by deformed lattice. Note that now you can position the sine any way you want because deformer set exclusion will keep base of the fin in place.

[christian-docksey]

QUOTE(failure @ 12/28/05, 05:55 PM)
Ok and here is na example with dense mesh driven by deformed lattice. Note that now you can position the sine any way you want because deformer set exclusion will keep base of the fin in place.
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Great failure.... you couldn't have done better! I see how you rotate the handle to get what you want. Well, obviously one is forced to have the waves travelling in a particular direction to be able to control the falloff. For the direction I wanted, the falloff doesn't give the results wanted..... So in the end I'm using your method....waves aren't ideal for what's needed but I can get on with the project instead of being stuck so long with the same problem.

Thank you so much or the examples ... I find that without the lattice it's working fine for me. You saved my life with this!!

Happy New Year
Cheers