SKIN for hands?
18 messages in this thread
Hi all, I'm working with Puppeteer and Flock of Birds motion capture
to do character animation. I'd like to be able to animate characters
without using joints– using SKIN.AXP to fill in with render-time
deformations. I read the thread (and checked out the mesh) from M.G.
Batchelor, re the wishbone guy. Then I tried making hands with
multiple SKIN cylinders– one for each finger– that run together
along the palm, then meet up with the wrist SKIN. But the finger
SKINs have hard seams between them in the palm, and the connection to
the wrist is also hard-looking. Also saw the image of a female nude
in progress, made with SKIN. How were the joints hidden there? The
wishbone-man looked good, but how do you do that with an arm going
into a torso, and a neck coming out of that? It's a four-way SKIN
problem. Then animation of these slices is a whole other deformation
problem. Sorry about the length of this…
Has anyone tried hands/arms/torsos/legs/necks/etc with SKIN? Any tips?
<< I'd like to be able to animate characters without using joints–
using SKIN.AXP to fill in with render-time deformations. I read the
thread (and checked out the mesh) from M.G. Batchelor, re the
wishbone guy. Then I tried making hands with multiple SKIN cylinders
>>
<< How were the joints hidden there? >>
Sorry, I don't have a lot of time now to elaborate, plus I've posted
some info here on this subject before. The entire female mesh as well
as the little wishbone guy doesn't use cylinders…well, yes they do.
But they're vertically-squashed cylinders (EXTRUDED PLANAR SLICES).
Skin.axp only uses one set of vertices from the 3D slice object.
Anyway, the whole seamless joints thing is quite contrived & doesn't
work in all situations. It's a combination of:
1) Create a dummy skeleton for reference which will be hidden at
render-time.
2) Lay out & form your CS-Slices using the skeleton reference.
3) Lay them out & scale them in such a way as to have "inner loops"
hidden by the outer surface. This allows you to conceal breaks & very
obvious seams. Sometimes you will have slices at the exact same
point in space, with one perhaps being a smaller diameter than the
outer visibly-skinned one. It's very important as to the direction of
the "path" that Skin.axp takes when fitting the spline surface to the
lattice defined by the CS's.
4) The staging, framing, lighting, & material definitions must be
very contrived to minimize the obvious seams, cracks, flaws, etc..
For instance, making a skin material's Ambient color darker than the
Diffuse color will just accent the seam flaws due to the shading.
Avoid this, fill in with lighting, choose appropriate camera &
lighting angles. The model construction really dictates the framing &
motion to a degree in this case – in order to produce the
"misdirection".
5) Once it looks acceptable, assign CS's to the already-linked
skeleton, animate it, then hide the skeleton for rendering.
I can't begin to get in to the actual construction techniques, as it
is different for every subject. Just bear in mind that you can hide
inner loops of skin as I said. Hands are very tough if viewed
close-up.
Bill,
Thanks for the input. SKIN is great for some things, but for our needs I think
we'll have to go with Schreiber's Metareyes metaballs for the hands, and skin
for the rest of the body. I'll be uploading some images soon.
Thanks again for your help.
Eric Chadwick
Mechadeus/Mondo Media
You bet. If you're going to use Metaballs which are converted to polygons, why
not just construct the hands with the 3DS native modeler, and weld the fingers
to the palms ? Anyway, good luck with it.
BILL
Bill, The reason I'd use metaballs for the hands is meta's on-the-fly
animated surfacing, not for modeling a polygon mesh. If polygons
could be deformed actively by attaching control vertices to motion
capture receivers, then that'd be perfect. I'm guessing that the only
way to attach 3d fingers and hands to motion capture in 3dstudio is
with a skin-like animated surface, using the slices (or metaballs) as
CVs for the mocap hardware to move around. Any other suggestions out
there for this kind of problem? The hands are for a realistic human
character that will be punching the camera, so the hand comes up real
close. There will be some motion blur to hide some stuff, but
otherwise, I'd like to see a good-looking hand. To speed up a <HUGE>
human animation task for our next game title, we're using Schreiber's
Puppeteer and Ascension's Flock to do most of the animation. Hope it
works… (sweat…sweat…)
Eric Chadwick
Mechadeus/Mondo Media
Gee, I didn't realize you were using MC data for the hands, and I
hope Puppeteer works out OK. I only used the very first version, and
it was a bit frustrating at that time. I don't know anything about
how you could get motion data to R4's IK, personally – but I'm sure
there's a way. I was just referring to constructing the jointed hands
& fingers, then welding the fingers at the knuckles – to the palms,
for a totally seamless hand. You could certainly construct a
skeltonal control system for the mesh, use Deform.pxp or even perhaps
IK or Bones, but I don't know about using the MC data. Sorry. Anyway,
good luck with it !
Thanks… we'll need the luck…
We're using MC data through Puppeteer to completely animate the characters,
then I hope to use IK for tweaking.
The real problem lies in animating seamless joints without the use of
morphs– we can't attatch morphs to motion capture, and I haven't
found(or heard)of a way to get MC info to deform polygons smoothly.
Maybe this shareware BONES ipas will evolve into an AXP?
Thanks Bill for posting your wishbone stick figure… it was a real
eye-opener.
Eric Chadwick
Mechadeus/Mondo Media
You're welcome. Sounds like your best bet might be to check with Dave at
Digimation regarding THEIR bones routine. I have not used or tested it myself,
but if an object can have several skeletal braches (or any), you might could
construe some way to feed the MC data to the spline skeleton – which would
(should) deform the mesh polygons smoothly. Since an un-sliced mesh can not be
deformed locally in the keyframer, this sounds like the closest possibility.
Unless you can manage to use the wishbone guy's techniques and other
misdirection at the knuckles with skeletonally-driven Skin slices.
BILL
Bill,
Sounds great. BTW, I'm kind of new to compuserve, and I'd like to upload some
sample animations and stills from our upcoming game The Daedalus Encounter.
What file formats do you think would be best for forum members? I'd like to
show the anims in 24-bit if possible.
Eric
PMJI, but use JPEG. This way, the images will still be true-color, but also a
manageable download size. I've seen a couple images from your DE game in
mags, and they look terrific! I'd sure like to get a look at them 'en
moniter'.
Dave
If you want to upload 24-bit, try .jpg. other than that, there is the old
standby GIF for 8 bit.
They will look better in JPEG, but if they are only going to be 640x480x256 in
the game, then upload in that resolution. I want to see how they will look in
the game, not how they will look in 16million colors.
Judy
A few JPEGs are coming soon. Actually, the animations are all 24-bit,
320×240. Most of the time, we'll be doubling them to fullscreen, but
processor power and the color depth depend of course on the machine.
The JPEGs will be un-video-compressed, unlike the anims, which we'd
like to have run at 15 frames per second in Windows. Hopefully it'll
look a lot better on 3DO, without so much compression. It's a real
drag to see those hard-earned details turn to mush… but hey, we're
talking Windows here.
Eric,
<< I'd like to upload some sample animations and stills from our
upcoming game The Daedalus Encounter. What file formats do you think
would be best for forum members? I'd like to show the anims in 24-bit
if possible. >>
Sorry, I was off-line for a day. I agree with everyone else, for
stills upload JPEG. For 24-bit flics, I don't know….never created
any other than 8-bit. Maybe someone else can jump in on this. Look
foward to seeing them.
Regards,
BILL
Eric Mondo,
>> attach 3d fingers and hands to motion capture in 3dstudio is with a
skin-like animated surface, using the slices (or metaballs) as CVs for the
mocap hardware to move around. Any other suggestions out there for this kind of
problem? <<
If you have r4 and if you can capture the xyz co-ords of the mocap
hardware into a file (preferably ascii or better still, in .vue file
format) it would be quite easy to write a script to parse the info
and assign it to dummy objects – a .vue file would require no further
interpretation. Each dummy would represent a joint. These dummies
would then be used as IK follow objects for your character. Not
terribly hard I don't think, some coding/scripting required, don't
try this at home <g>.
Howdy Martin!
I think what you're describing is what Schreiber's software already does. It
links directly to the MC hardware, and uses an IK-like skeleton to animate the
mesh.
Our problem lies in animating seamless joints without the use of morphs– we
can't attatch morphs to motion capture, and I haven't found(or heard)of a way
to get MC info to deform polygons smoothly, except the SKIN or METABALL ipas.
Maybe this shareware BONES ipas will evolve into an AXP?
Eric Chadwick
Mechadeus/Mondo Media