Please refer to the message entitled "car ad" in p.b.i.

I've been playing around with blobs to model a car and I am having a
little problem with making them coincide properly.  The nose of the car
is a succession of smaller cylindrical blob objects and no amount of
playing with the radius or strength of the individual oblects will do
away with the "Michelin man" appearance.  If you look at the reflection
of the mountain, you'll see what I mean.

Any ideas?  More blobs?  Bigger radii?  Stronger values?

Howard?

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Francois Labreque | Rimmer: "Let's go to red alert!"
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"Francois Labreque" <fla### [at] attglobalnet> wrote in message
news:395EAFC2.B8626649@attglobal.net...
|
| Any ideas?  More blobs?  Bigger radii?  Stronger values?

More blobs.  Didn't want to hear that I bet.  I've never seen perfectly linked
components when I try to make something out of a blob object.  It's something
to do with the math at the intersecting areas I guess.
You can try to increase strength and/or lower the threshold, but it isn't
likely you'll get absolutely smooth connection points with a mere half dozen
components, in my opinion anyway.

Bob

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On Sat, 01 Jul 2000 22:58:10 -0400, Francois Labreque
<fla### [at] attglobalnet> wrote:

>I've been playing around with blobs to model a car and I am having a
>little problem with making them coincide properly.  The nose of the car
>is a succession of smaller cylindrical blob objects and no amount of
>playing with the radius or strength of the individual oblects will do
>away with the "Michelin man" appearance.  If you look at the reflection
>of the mountain, you'll see what I mean.
>
>Any ideas?  More blobs?  Bigger radii?  Stronger values?

Less blobs, larger radius, smaller strength, greater threshold. That's
how I solved the problem when it arose yesterday during the creation
of the twisted torus thingy. Basically, the lower the threshold and
the greater the strength, the less likely are the components to 'blob'
together and the more liable they are to jagging. Vice versa, when
they are of smaller strength (therefore requiring a larger radius to
compensate for that) and the threshold is higher, more components'
contributions are needed to overcome the threshold, causing them to
blob together.

I hope I made this clear enough, it's a little past 7 am and I am not
used to getting up so early so please forgive any oddities.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] usanet
TAG      e-mail : pet### [at] tagpovrayorg

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Bob Hughes wrote:
> 
> "Francois Labreque" <fla### [at] attglobalnet> wrote in message
> news:395EAFC2.B8626649@attglobal.net...
> |
> | Any ideas?  More blobs?  Bigger radii?  Stronger values?
> 
> More blobs.

"@#/$%?&*!"

> Didn't want to hear that I bet.

No.  But I was expecting it.

-- 
Francois Labreque |   //\\    Wear an ASCII ribbon!
     flabreq      |  ||  ||   
        @         |   \\//    Support the campain
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Peter Popov wrote:
> 
> >Any ideas?  More blobs?  Bigger radii?  Stronger values?
> 
> Less blobs, larger radius, smaller strength, greater threshold. That's
> how I solved the problem when it arose yesterday during the creation
> of the twisted torus thingy. Basically, the lower the threshold and
> the greater the strength, the less likely are the components to 'blob'
> together and the more liable they are to jagging. Vice versa, when
> they are of smaller strength (therefore requiring a larger radius to
> compensate for that) and the threshold is higher, more components'
> contributions are needed to overcome the threshold, causing them to
> blob together.

Makes sense.  I'll give it a try.

> 
> I hope I made this clear enough, it's a little past 7 am and I am not
> used to getting up so early so please forgive any oddities.

That's alright.  I, too, was up at the crack of dawn (so to speak!). 
Jacques Villeneuve finally has a racecar!  Yay!


> 
> Peter Popov ICQ : 15002700
> Personal e-mail : pet### [at] usanet
> TAG      e-mail : pet### [at] tagpovrayorg

-- 
Francois Labreque |   //\\    Wear an ASCII ribbon!
     flabreq      |  ||  ||   
        @         |   \\//    Support the campain
  attglobal.net        \\     against HTML e-mail!
                      //\\

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It varies so much from instance to instance it is difficult to keep track of
how blob components interact.  As Peter was suggesting using larger radius,
smaller strength, and larger threshold can smooth them out it also takes close
proximity too or else you still get the "interaction zone crease".  So you
would need more components I believe, not fewer.

Bob

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"Bob Hughes" wrote:
> It varies so much from instance to instance it is difficult
> to keep track of how blob components interact.  As Peter was
> suggesting using larger radius, smaller strength, and larger
> threshold can smooth them out

Isn't lowering the strength of all components basically the same as
increasing the threshold? I think multiplying the strengths of all the
components with 2 give the same result as dividing the threshold with 2. Is
that correct?

Greetings,

Rune
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"Rune" <run### [at] inamecom> wrote in message
news:3960e81e@news.povray.org...
|
| Isn't lowering the strength of all components basically the same as
| increasing the threshold? I think multiplying the strengths of all the
| components with 2 give the same result as dividing the threshold with 2. Is
| that correct?

You are probably correct about that.  As long as the threshold and strength
remain in sync the blob is the same at any(?) value.  A 'threshold' at
one-forth of a control value is the same as 'strength' at 4 times the control
value when threshold is set back again and vice versa.

Bob

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In article <3960e81e@news.povray.org>, "Rune" <run### [at] inamecom> 
wrote:

> Isn't lowering the strength of all components basically the same as
> increasing the threshold? I think multiplying the strengths of all the
> components with 2 give the same result as dividing the threshold with 2. 
> Is that correct?

Not quite. The falloff curve is kind of S-shaped, it isn't linear, so 
the way the components blob together and the distance of the surface 
from their centers will change.

-- 
Christopher James Huff - Personal e-mail: chr### [at] maccom
TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
Personal Web page: http://homepage.mac.com/chrishuff/
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there's a great beginner tutorial out there.  i think it is by jeff
lee.  one of the things he shows is how blobs of different radii can
have the same appearant radius, but still interact quite differently.  i
believe this is the exact thing this thread has been talking about.

Chris Huff wrote:
> 
> In article <3960e81e@news.povray.org>, "Rune" <run### [at] inamecom>
> wrote:
> 
> > Isn't lowering the strength of all components basically the same as
> > increasing the threshold? I think multiplying the strengths of all the
> > components with 2 give the same result as dividing the threshold with 2.
> > Is that correct?
> 
> Not quite. The falloff curve is kind of S-shaped, it isn't linear, so
> the way the components blob together and the distance of the surface
> from their centers will change.
> 
> --
> Christopher James Huff - Personal e-mail: chr### [at] maccom
> TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
> Personal Web page: http://homepage.mac.com/chrishuff/
> TAG Web page: http://tag.povray.org/

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