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Re: Movements dino's could have made (was: Re: Deinonychus claws; lo



Jarno Peschier wrote:
> > I suppose that no one has ever thought to make casts of the bones of
> > dinosaurs and reassemble them,then move them around to see what
> > movements these creatures could and could not have made.
> 
> Why make casts and try ot move them around if you can digitize the
> bones and do all the "playing with possible movements" on a powerful
> 3D modelling computer...?

because bones in real life may show tiny details that the 3d model might
not, that would allow the 3d model to do movements that upon closer
examination of the actual bone, might have evidence that it simply
couldn't do some motions allowed by the software. There might be
evidence of a flange that might have been too stiff to allow such a
movement, or a tiny remnant of cartiligenous attachment that shows as a
stain on the bone and wouldn't show up at all on the model.

Modelling in computer is dependant of first having ALL the information
collected off of the actual bone.  That's a lot of information!
Not all such information is inherent in animation packages but must be
inferred by the anatomist.

Dr. Kevin Padian has sone reconstruction work with pterosaur skeletons.
Since most pterosaur bones are preserved in a highly flattened state, he
studied the best preserved specimins of each bone of the animal
(Pteranodon, I think) and created a real-time scultporal master bone
model, and then attached them roughly in an armature to examine their
articulation.

However, some paleontologists (and students such as John Hutchinson of
Berkeley-Hi John!) are studying the problem as software becomes more
responsive to the demands made on it by paleontologists.  Most medical
articulation software is written with much assumed by human standards
already by the software as there is so much already known about human
motion, but to find something that is just as powerful, but allows you
to input ALL data is harder to find, and it's also harder to find a
paleontologist that knows that much about such a fairly new medium.  

It takes about 4 months just to get a handle on some of the basic
animation packages used by film companies such as SoftImage or Alias or
Wavefront, and that's NOT even mentioning collecting and inputting
comparitive anatomy data that would also be necessary.  Nor musclular
force formulae, gravity formulae, bone strength formulae, etc, etc
etc.....

The animation packages used by special effect film companies can allow
you to wierd things like take the rear leg of a Triceratops and touch
the back of the head with it, sometimes by passing THROUGH the animal
itself, depending on what the animator or programmer involved tells the
program to watch out for this.  You can have problems show up like
having the animal walk out of it's own skin.  All sorts of things become
complicated in the non-specific animation packages like those used in
movies.  The medical software is more accurate to the forces the
paleontologist wants to work with.

lastly, paleontologists rarely have any money to pay for such a nice
computer set up and they have to usually borrow time on a university
computer used by medical or veterinary students, so time on the machines
is rare and precious! (time to learn the package, time to input the
data, time to do the computations necessary, time to do the rendering,
and then have room to store all this information.)

That's why it probably hasn't been done all that often up to now.

-- 
           Betty Cunningham  
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