"Rune" <run### [at] runevisioncom> wrote:
>
> Extruding a mesh along a spline which happens to go through some points in a
> skeleton is not the same as deforming a mesh directly according to the bones
> in a skeleton.
>
> Your technique no doubt worked for your specific alien characters (that look
> like they're made of sphere_sweeps) but are you claiming it can be used as a
> general method to animate mesh characters such as your MIME Man or my AL the
> Alien character (provided they were meshes to begin with)?
>



Good question. First of all, rather than "boning", I would use the term if
we're talkig povray of "transforms".  I have shin transforms, right eye
transforms, forearm transforms, even left index finger middle digit
transforms in my system.  If you set up transforms, then you can have
"anything" you want move to the same set of transforms. I primarily think
in transforms but I can have it spit out points if I choose.


There are several levels of difficulty to the problem you describe, perhaps
it's best to consider individually:

1).  Animation of a "single long stocking"-- say going from a foot to an
ankle to a knee up to the crotch.   This I believe is quite doable using
(hoping I'm not insulting him by invoking his name  and quality macro in
assocation with my mediocre work) the Mike Williams method.  I made
(perhaps unpublished?) a simple example like this and think it's quite
"workable" with a more professional-quality construction if one were to
choose.   If you don't care exactly how smoothly Al's arms connect to his
torso, if you'd settle for mere overlapping objects, then the answer is a
flat "yes".

2). Animation of "a pair of pants" or a "sweater"-- say two independently
moving legs which smoothly join to a "hip & but" or two independently
moving arms smoothly joining to a "torso". (A more complex version would be
multiple fingers joining a hand).  This is currently over my head, although
I'm currently skeptical that it's impossible with the Mike Williams method.
I think it's just a slightly bigger coding headache and this discussion is
almost about made me want to try it.

3). Animation of a moving jaw within a mouth with an opening.  This I think
is doable, too.

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gregjohn wrote:
> "Rune" <run### [at] runevisioncom> wrote:
>>
>> Extruding a mesh along a spline which happens to go through some
>> points in a skeleton is not the same as deforming a mesh directly
>> according to the bones in a skeleton.
>>
>> Your technique no doubt worked for your specific alien characters
>> (that look like they're made of sphere_sweeps) but are you claiming
>> it can be used as a general method to animate mesh characters such
>> as your MIME Man or my AL the Alien character (provided they were
>> meshes to begin with)?
>
> Good question. First of all, rather than "boning", I would use the
> term if we're talkig povray of "transforms".

It's basically the same thing. You need one or two transforms to specify the
alignment of a bone.

> If you don't care exactly how smoothly Al's arms connect to
> his torso, if you'd settle for mere overlapping objects, then
> the answer is a flat "yes".

But I do. That's kind of the whole point with the technique.

> 2). Animation of "a pair of pants" or a "sweater"-- say two
> independently moving legs which smoothly join to a "hip & but" or two
> independently moving arms smoothly joining to a "torso".

> I think it's just a slightly bigger coding headache and
> this discussion is almost about made me want to try it.

If you mean it'd be a new coding headache every time you have a new model or
skeleton, then you're missing the point. Deforming a skeleton according to
bones is a general technique that, once coded, don't require any additional
coding no matter how different the models and skeletons are. If on the other
hand you think you *do* have a general-purpose solution, then I wish you
good luck coding it.

> 3). Animation of a moving jaw within a mouth with an opening.  This I
> think is doable, too.

Again, this should be possible using the same code as for the pants and
sweater.

Rune
-- 
3D images and anims, include files, tutorials and more:
rune|vision:  http://runevision.com
POV-Ray Ring: http://webring.povray.co.uk

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"Rune" <run### [at] runevisioncom> wrote in message
news:41324cbb$1@news.povray.org...
> > 2). Animation of "a pair of pants" or a "sweater"-- say two
> > independently moving legs which smoothly join to a "hip & but" or two
> > independently moving arms smoothly joining to a "torso".
>
> > I think it's just a slightly bigger coding headache and
> > this discussion is almost about made me want to try it.
>
> If you mean it'd be a new coding headache every time you have a new model
or
> skeleton, then you're missing the point. Deforming a skeleton according to
> bones is a general technique that, once coded, don't require any
additional
> coding no matter how different the models and skeletons are. If on the
other
> hand you think you *do* have a general-purpose solution, then I wish you
> good luck coding it.
>


Consider the 'sweater' example.  I can envision a general model which works
of course for the first character you design with it. But if everything is
procedurally generated, then you can tweak skeletal points as well as the
splines that define the arm diameters as well as the spline that defines the
shape of the torso.  It shouldn't be too hard to go from robot to man to
woman to puppy dog once you've got the system.  You would however be locked
into designing the character within this system--or to put another spin on
it, blessed by having a totally procedurally generated, portable, 100%
povray, SDL-only character.  I intuitively appreciate this philosophy,
especially if it were politically incorrect with certain artsy-fartsy types.
To quote a recent winner of an IRTC Animation round, (from memory),  "Using
povray for character animation must be a complete waste of time".

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Greg M. Johnson wrote:
> It shouldn't be too hard to go from robot to man to woman to puppy
> dog once you've got the system.

Those all have four limbs, placed relatively the same way. How about bird,
dragon, three-armed alien, spider, worm?

> You would however be locked into designing the
> character within this system--or to put another spin on it, blessed
> by having a totally procedurally generated, portable, 100% povray,
> SDL-only character.

You just don't do detailed or realistic models that way. You haven't done
it, I haven't done it, nobody have yet. Meshes are the way to go for any
serious purposes (or possible bicubic patches). And I know you can do
procedural meshes, but those too are not of the detail level you can do with
a modeler. If you only need toons, you might do fine, but for serious work
it won't do.

> I intuitively appreciate this philosophy,
> especially if it were politically incorrect with certain artsy-fartsy
> types. To quote a recent winner of an IRTC Animation round, (from
> memory),  "Using povray for character animation must be a complete
> waste of time".

I've been very much a POV purist. My animation attempts with AL the Alien
proves that. Despite that I've come to the conclusion that doing character
animation *completely* within POV-Ray *is* a waste of time. That is, if
you're not satisfied with blobby toons, unsmooth joints etc.

Rune
-- 
3D images and anims, include files, tutorials and more:
rune|vision:  http://runevision.com
POV-Ray Ring: http://webring.povray.co.uk

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"Rune" <run### [at] runevisioncom> wrote:

> If you only need toons, you might do fine, but for
> serious work it won't do.
>


I take offense at the implied dichotomy between "toon" and "serious". (Not
personal, but intellectual or ideological offense).  "The Incredibles",
Pixar's next film, I predict, will earn GOBS of cash (a professional
achievement) and will represent a technical achievement on the par  of
Jar-Jar Binks or Gollum.


> Despite that I've come to the conclusion that doing character
> animation *completely* within POV-Ray *is* a waste of time. That is, if
> you're not satisfied with blobby toons, unsmooth joints etc.
>


I guess my view is that going from a serious modeller to povray is a waste
of time.  It's just another tracer.  The coolness of povray (perhaps a
rarely held opinion) is in its being freeware and allowing the script-based
generation of objects. If I were to get another program to make the
objects, it would seem to make sense to have that program take the
pictures, too.

That being said, I think it would be a great boon if someone were to make a
bending bicubic patch animatable within povray.

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>  The coolness of povray (perhaps a
> rarely held opinion) is in its being freeware and allowing the
script-based
> generation of objects.

The script based generation is nice, but from my viewpoint, nothing I have
ever seen or used beats POV-Ray for control over light.  Many times, I've
placed point sources only .001 POV unit away from an obstruction to get the
light exactly where I wanted it to come from.  Interior lighting with Poser
has been nothing but frustration, I'll normally export the scene without
lights and do the lighting in POV.  Clumsy, inefficient, but exactly what
I'm seeing in my head.  Pretty hard to beat.

Greybeard

(Who isn't going to spend a kilobuck to get what POV allows me to do.)

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Rune wrote:

> I've been very much a POV purist. My animation attempts with AL the Alien
> proves that. Despite that I've come to the conclusion that doing character
> animation *completely* within POV-Ray *is* a waste of time. That is, if
> you're not satisfied with blobby toons, unsmooth joints etc.

Organic shapes of any kind are far, far, easier to do with a modeler
than with hand-written SDL.

Case in point:  The green aliens in my April 2004 entry would have taken
weeks to create using hand-edited SDL code.  Using the modeler I've
developed, I generated the model in only a couple hours.  This enabled
me to move on to other portions of the work.

It's true that the aliens ride floating carts which are done in SDL,
but SDL *is* good for some things.

SDL can procedurally generate a small subset of organic shapes, such as
trees.  The petrified trees that appear in most of my Rusty animations
were generated this way, but I *never* let the camera get close enough
to reveal how little detail they have; the limbs and trunks are eight-
sided prisms, with smoothed normals, and there are only three different
trees (each being copied many hundreds of times).

It's also true that all the time Greg has spent trying to get a decent
human from SDL has probably resulted in development of some useful
scripting techniques.  Whether this is worth the immense amound of time
invested is another matter.

I'm reminded of some of Howard Day's stuff.  Instead of doing procedural
textures, he simply rendered an silhouette of the model, used a paint
program on the resulting image, and then made the image into an
image_map and applied it to the model.  He'd probably still be getting
some of the textures right if he'd stuck with SDL, but instead he was
able to devote more time to the ticky parts of the work.

Regards,
John

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gregjohn wrote:

> "Rune" <run### [at] runevisioncom> wrote:
> 
>>If you only need toons, you might do fine, but for
>>serious work it won't do.
> 
> I take offense at the implied dichotomy between "toon" and "serious". (Not
> personal, but intellectual or ideological offense).  "The Incredibles",
> Pixar's next film, I predict, will earn GOBS of cash (a professional
> achievement) and will represent a technical achievement on the par  of
> Jar-Jar Binks or Gollum.

One issue that is important is the ability to get the *exact* effect you
want with the minimal expenditure of time.  SDL can do everything, but
the investment of lifespan is too long for some effects.

>>Despite that I've come to the conclusion that doing character
>>animation *completely* within POV-Ray *is* a waste of time. That is, if
>>you're not satisfied with blobby toons, unsmooth joints etc.
> 
> I guess my view is that going from a serious modeller to povray is a waste
> of time.  It's just another tracer.  The coolness of povray (perhaps a
> rarely held opinion) is in its being freeware and allowing the script-based
> generation of objects.

Another beneift of POV-Ray is that I can use the SDL to make alignments
of objects far more precisely than any modeler can allow for the same
amount of lifespan invested.

Regards,
John

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> I'm not sure I have the required skills, but I'd like to write a program in
> Java that can import a boned mesh in some format, move the bones around,
> deform the mesh according to the moved bones and then export the mesh as a
> mesh2 for example.
> 
> Are there any widely used formats for boned meshes?
> 
> It should contain the mesh (typically a character in some standard pose),
> the bones in the same standard pose, and data about which vertices are
> affected by which bones.
> 
> However, in order to deform the mesh correctly, I'd probably also have to
> know the algorithm used for the deforming. Even with that available I might
> not have the skills, but I can always hope.
> 
> I think I have to base it all on a pre-existing format for boned meshes,
> because how else would people be able to actually create those boned meshes?
> I certainly don't have the skills to create a graphical mesh and boning
> modeler/editor.
> 
> Any ideas?
> 
> Rune
You may have a look at this
http://projects.blender.org/projects/makeh

I havn't look further whet it is exactly but I thought it might be usefull.

--
Clipper

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"GreyBeard" <r.b### [at] sbcglobalnet> wrote in message
news:4132b2a2$1@news.povray.org...
>
> The script based generation is nice, but from my viewpoint, nothing I have
> ever seen or used beats POV-Ray for control over light.  Many times, I've
> placed point sources only .001 POV unit away
>


I'm sure my computer lingese is lacking. I guess this is in a way a benefit
of "scripting."

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