Here I've tried to use my walking system to animate a spider. I've tried to
get that look and feel of a real spider. Instead of just lifting off every
second leg on the same time I've made small "waves" come down through the
legs by first lifting the front right leg, then the second left, then the
third right, then the fourth left and then the same for the other four legs.

I had to create my own inverse kinematics 3-limb macro that finds two
"knees" per leg rather than just one. The only way I could think of doing
that was by estimation, found by using a loop to "guess" the values
repeatedly until it's close enough.

I've been working a lot on my walking system, practically rewriting it from
scratch, which has paid off in the form of added flexibility. It's still
based on the same basic method as the code I posted in
povray.binaries.scene-files, yet with a somewhat different approach. I had
been thinking about this: What happens when you begin to walk twice as fast?
Do you take twice as long steps or do you just take each step in half the
time? Fact is that it's a combination, and my system takes that into account
when calculating where to put the feet.

My code analyses the walk path and takes lots of samples of various kinds
along it. Then it interpolates between the samples and find out which places
to place which feet at which times. The parsing takes a little while, so all
the data is saved to a file (in the form of double-nested arrays and other
things) and is then just included for the rest of the frames in the
animation.

Well, enough details, have a look at the result so far and let me know what
you think! :)

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

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Attachments:
Download 'spider.mpg' (193 KB)

Coooool :-)
Are you planning to release a full IK walk include? || 8-0

--

//Mahalis
camera{location<0,0.25,-2> look_at 0.5*y} #declare T=texture{pigment{crackle
scale 0.5 rotate 90 turbulence 0.75 color_map{[0 rgb 1][0.05 rgb 1][0.1
rgb<1,0.25,1>][0.25 rgbf 1][1 rgbf 1]}} finish{ambient 1}} #declare
c=difference{torus{0.5,0.1 rotate -90*x}box{<0.7,0,0.2>,<-0.7,-0.7,-0.2>}}
merge{object{c translate<0.5,0.5,0>} object{c translate<-0.5,0.5,0>}
cylinder{<1,0.5,0>,<1,0,0>,0.1} cylinder{<-1,0.5,0>,<-1,0,0>,0.1}
cylinder{0.5*y,0,0.1} texture{T}}
--


"Rune" <run### [at] mobilixnetdk> wrote in message
news:3be34edf@news.povray.org...
> Here I've tried to use my walking system to animate a spider. I've tried
to
> get that look and feel of a real spider. Instead of just lifting off every
> second leg on the same time I've made small "waves" come down through the
> legs by first lifting the front right leg, then the second left, then the
> third right, then the fourth left and then the same for the other four
legs.
>
> I had to create my own inverse kinematics 3-limb macro that finds two
> "knees" per leg rather than just one. The only way I could think of doing
> that was by estimation, found by using a loop to "guess" the values
> repeatedly until it's close enough.
>
> I've been working a lot on my walking system, practically rewriting it
from
> scratch, which has paid off in the form of added flexibility. It's still
> based on the same basic method as the code I posted in
> povray.binaries.scene-files, yet with a somewhat different approach. I had
> been thinking about this: What happens when you begin to walk twice as
fast?
> Do you take twice as long steps or do you just take each step in half the
> time? Fact is that it's a combination, and my system takes that into
account
> when calculating where to put the feet.
>
> My code analyses the walk path and takes lots of samples of various kinds
> along it. Then it interpolates between the samples and find out which
places
> to place which feet at which times. The parsing takes a little while, so
all
> the data is saved to a file (in the form of double-nested arrays and other
> things) and is then just included for the rest of the frames in the
> animation.
>
> Well, enough details, have a look at the result so far and let me know
what
> you think! :)
>
> Rune
> --
> 3D images and anims, include files, tutorials and more:
> Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
> POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
> POV-Ray Webring: http://webring.povray.co.uk
>
>
>

Post a reply to this message

Creepy!

Looks good, with so many legs it's hard to watch if one slips up.
Perhaps you did that on purpose ;)

-tgq

"Rune" <run### [at] mobilixnetdk> wrote in message
news:3be34edf@news.povray.org...
> Here I've tried to use my walking system to animate a spider. I've tried
to
> get that look and feel of a real spider. Instead of just lifting off every
> second leg on the same time I've made small "waves" come down through the
> legs by first lifting the front right leg, then the second left, then the
> third right, then the fourth left and then the same for the other four
legs.
>
> I had to create my own inverse kinematics 3-limb macro that finds two
> "knees" per leg rather than just one. The only way I could think of doing
> that was by estimation, found by using a loop to "guess" the values
> repeatedly until it's close enough.
>
> I've been working a lot on my walking system, practically rewriting it
from
> scratch, which has paid off in the form of added flexibility. It's still
> based on the same basic method as the code I posted in
> povray.binaries.scene-files, yet with a somewhat different approach. I had
> been thinking about this: What happens when you begin to walk twice as
fast?
> Do you take twice as long steps or do you just take each step in half the
> time? Fact is that it's a combination, and my system takes that into
account
> when calculating where to put the feet.
>
> My code analyses the walk path and takes lots of samples of various kinds
> along it. Then it interpolates between the samples and find out which
places
> to place which feet at which times. The parsing takes a little while, so
all
> the data is saved to a file (in the form of double-nested arrays and other
> things) and is then just included for the rest of the frames in the
> animation.
>
> Well, enough details, have a look at the result so far and let me know
what
> you think! :)
>
> Rune
> --
> 3D images and anims, include files, tutorials and more:
> Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
> POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
> POV-Ray Webring: http://webring.povray.co.uk
>
>
>

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"Trevor Quayle" wrote:
> Creepy!

Good. :)

> Looks good, with so many legs it's hard to watch
> if one slips up. Perhaps you did that on purpose ;)

No, they don't slip up... I made this one to demonstrate to others as well
as to myself that the method works fine for things with many legs such as
spiders or bugs. :)

I'll post things with fewer legs at some other time, with more advanced
walk/run cycles.

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

Post a reply to this message

"Mahalis" wrote:
> Coooool :-)

Thank you! :)

> Are you planning to release a full IK walk include? || 8-0

No. There'd be too many problems with that at the moment...

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

Post a reply to this message

Very nice! The only thing I would comment is that it looks a bit "hoppy",
like the body bobs up and down, instead of rotating or whatever it is that
it does. I'm very impressed with all these things you manage to get POV to
do. I wish I knew more about math and such...

Post a reply to this message

That's very very realistic. It actually gave me that creepy feeling I get
when I look at big spiders and stuff like that.

- Slime
[ http://www.slimeland.com/ ]
[ http://www.slimeland.com/images/ ]

"Rune" <run### [at] mobilixnetdk> wrote in message
news:3be34edf@news.povray.org...
> Here I've tried to use my walking system to animate a spider. I've tried
to
> get that look and feel of a real spider. Instead of just lifting off every
> second leg on the same time I've made small "waves" come down through the
> legs by first lifting the front right leg, then the second left, then the
> third right, then the fourth left and then the same for the other four
legs.
>
> I had to create my own inverse kinematics 3-limb macro that finds two
> "knees" per leg rather than just one. The only way I could think of doing
> that was by estimation, found by using a loop to "guess" the values
> repeatedly until it's close enough.
>
> I've been working a lot on my walking system, practically rewriting it
from
> scratch, which has paid off in the form of added flexibility. It's still
> based on the same basic method as the code I posted in
> povray.binaries.scene-files, yet with a somewhat different approach. I had
> been thinking about this: What happens when you begin to walk twice as
fast?
> Do you take twice as long steps or do you just take each step in half the
> time? Fact is that it's a combination, and my system takes that into
account
> when calculating where to put the feet.
>
> My code analyses the walk path and takes lots of samples of various kinds
> along it. Then it interpolates between the samples and find out which
places
> to place which feet at which times. The parsing takes a little while, so
all
> the data is saved to a file (in the form of double-nested arrays and other
> things) and is then just included for the rest of the frames in the
> animation.
>
> Well, enough details, have a look at the result so far and let me know
what
> you think! :)
>
> Rune
> --
> 3D images and anims, include files, tutorials and more:
> Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
> POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
> POV-Ray Webring: http://webring.povray.co.uk
>
>
>

Post a reply to this message

"Rune" <run### [at] mobilixnetdk> wrote in message
news:3be34edf@news.povray.org...
> Here I've tried to use my walking system to animate a spider. I've tried to
> get that look and feel of a real spider. Instead of just lifting off every
> second leg on the same time I've made small "waves" come down through the
> legs by first lifting the front right leg, then the second left, then the
> third right, then the fourth left and then the same for the other four legs.
>
> I had to create my own inverse kinematics 3-limb macro that finds two
> "knees" per leg rather than just one. The only way I could think of doing
> that was by estimation, found by using a loop to "guess" the values
> repeatedly until it's close enough.
>
> I've been working a lot on my walking system, practically rewriting it from
> scratch, which has paid off in the form of added flexibility. It's still
> based on the same basic method as the code I posted in
> povray.binaries.scene-files, yet with a somewhat different approach. I had
> been thinking about this: What happens when you begin to walk twice as fast?
> Do you take twice as long steps or do you just take each step in half the
> time? Fact is that it's a combination, and my system takes that into account
> when calculating where to put the feet.
>
> My code analyses the walk path and takes lots of samples of various kinds
> along it. Then it interpolates between the samples and find out which places
> to place which feet at which times. The parsing takes a little while, so all
> the data is saved to a file (in the form of double-nested arrays and other
> things) and is then just included for the rest of the frames in the
> animation.
>

Wow!

- Nekar


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
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in news:3be34edf@news.povray.org Rune wrote:

> Here I've tried to use my walking system to animate a spider.

This look very good Rune. There is something a bit unnatural in it, 
can't put my finger on it though. Maybe it's the unsmooth body movement 
Tony mentioned.

Ingo

-- 
Photography: http://members.home.nl/ingoogni/
Pov-Ray    : http://members.home.nl/seed7/

Post a reply to this message

I think that spiders do not hop their bodies up and down when they walk,
but the body advance smoothly like a spaceship while the legs do their
work.
  Try making it so that the body doesn't move up and down at all to see how
it looks like.

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

Post a reply to this message

Brilliant! Looks very realistic in its movements.

I made a spider around 3-4 years ago with the intention of animating
it. Hadn't heard of IK then. I gave up when the headaches started.
Could not avoid foot slippage on all legs. Had realised that, in
general, the larger the spider in real-life - the smoother the body
moved. Also had trouble trying to turn the beast - legs kept fouling
each other.

Alf

Post a reply to this message

"Tony[B]" wrote:
> Very nice!

Thanks! :)

> The only thing I would comment is that it looks a bit
> "hoppy", like the body bobs up and down

I noticed that too but only in the final render and I didn't want to
rerender then.

> I'm very impressed with all these things you manage
> to get POV to do. I wish I knew more about math and such...

I don't use advanced math, only things like solving linear equations and
such (ok, also a bit trigonometry occasionally). The tricky part is to have
the creativity to come up with the right techniques I guess.

One of the things I've learned that I've had the most use of in many
different projects is to take a lot of samples, store them in arrays, and
then interpolate linearly between them. It's extremely powerful. A typical
use is to move a point with constant speed along a spline even though the
spline doesn't have constant speed.

But anyway, so far all my animations have been merely tests. I admire those
who come beyond that...

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

Post a reply to this message

"Slime" wrote:
> That's very very realistic. It actually gave me that
> creepy feeling I get when I look at big spiders and
> stuff like that.

Excellent! That's what I was hoping. ;)

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

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"Nekar Xenos" wrote:
> Wow!

Thanks! :)

BTW, you don't need to quote my entire message just to say that...

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

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"ingo" wrote:
> This look very good Rune.

Thanks!

> There is something a bit unnatural in it, can't put my
> finger on it though. Maybe it's the unsmooth body movement
> Tony mentioned.

I think so...

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

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"Warp" wrote:
>   I think that spiders do not hop their bodies up and
> down when they walk, but the body advance smoothly like
> a spaceship while the legs do their work.

Yes, I agree.

Actually the hopping was not intentional, but caused by the fact that the
body position is based on an average of all the feet positions. I'll try to
change that.

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

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"Alf Peake" wrote:
> Brilliant! Looks very realistic in its movements.

Thanks! :)

> I made a spider around 3-4 years ago with the
> intention of animating it.

Maybe you could send me the model and if I like it I could use it for the
animation? :)

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

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Very impressive - now if you could convert your pending IK inc (grin) to a
bones system - deforming meshes and all that :))


--
Rick

Kitty5 WebDesign - http://Kitty5.com
POV-Ray News & Resources - http://Povray.co.uk
TEL : +44 (01270) 501101 - FAX : +44 (01270) 251105 - ICQ : 15776037

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Or maybe it's the fact that spiders don't tend to walk in a circle like that
unless the're drunk.. :-)

--

//Mahalis
camera{location<0,0.25,-2> look_at 0.5*y} #declare T=texture{pigment{crackle
scale 0.5 rotate 90 turbulence 0.75 color_map{[0 rgb 1][0.05 rgb 1][0.1
rgb<1,0.25,1>][0.25 rgbf 1][1 rgbf 1]}} finish{ambient 1}} #declare
c=difference{torus{0.5,0.1 rotate -90*x}box{<0.7,0,0.2>,<-0.7,-0.7,-0.2>}}
merge{object{c translate<0.5,0.5,0>} object{c translate<-0.5,0.5,0>}
cylinder{<1,0.5,0>,<1,0,0>,0.1} cylinder{<-1,0.5,0>,<-1,0,0>,0.1}
cylinder{0.5*y,0,0.1} texture{T}}
--


"Rune" <run### [at] mobilixnetdk> wrote in message
news:3be3e7ce@news.povray.org...
> "ingo" wrote:
> > This look very good Rune.
>
> Thanks!
>
> > There is something a bit unnatural in it, can't put my
> > finger on it though. Maybe it's the unsmooth body movement
> > Tony mentioned.
>
> I think so...
>
> Rune
> --
> 3D images and anims, include files, tutorials and more:
> Rune's World:    http://rsj.mobilixnet.dk (updated June 26)
> POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
> POV-Ray Webring: http://webring.povray.co.uk
>
>

Post a reply to this message

"Rune" <run### [at] mobilixnetdk> wrote in message
news:3be3e967@news.povray.org...
[snip]
> Maybe you could send me the model and if I like it I could use it
for the
> animation? :)


I don't have a decent source handy right now, its very modified and
messy. A mix of Pov 2.1, 3 and 3.1. I uploaded a clean source to
Compuserve around 97/98 so should have that archived around here
somewhere. I'll let you know if I find it.

These are some pics, the first may be a dead link now.
http://ourworld.compuserve.com/homepages/Alf_Peake/SPIDER.JPG
http://www.peake42.freeserve.co.uk/pix1/web2.jpg

Each leg has 4 segments, and each knee is a section of a torus divided
with a short cylinder inserted. Each knee was in a single plane and
could cover around 160 deg. An infinite number of solutions for each
shoulder / foot location :( I used "90 deg phase" between legs on one
side and 180 deg difference between sides.

Alf

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