"Chris Huff" wrote:
> "Rune" 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.

The shape of the falloff curve is irrelevant.

As long as 2 function remains the same *relative to each other*
the intersection points remains the same. The code below proves it.

The first row shows blobs where both the threshold and the strengths
increase with the same amount from left to right. The blob remain the same.

The second row shows blobs with increasing threshold, and the third row
shows blobs with decreasing strength. You can see that the two rows look
exactly the same.

light_source {<1,2,-3>*10, color 1}
#default {pigment {color rgb 1}}
#declare X = 1;
#declare Y = 7;
#while (X<Y)
   blob {
      threshold 1*X
      sphere {x, 1.5, 2*X rotate 000*z}
      sphere {x, 1.5, 2*X rotate 120*z}
      sphere {x, 1.5, 2*X rotate 240*z}
      scale 0.2
      translate <(X/Y)*6-3,+1.5,5>
   }
   blob {
      threshold 1*X
      sphere {x, 1.5, 8 rotate 000*z}
      sphere {x, 1.5, 8 rotate 120*z}
      sphere {x, 1.5, 8 rotate 240*z}
      scale 0.2
      translate <(X/Y)*6-3,0,5>
   }
   blob {
      threshold 1
      sphere {x, 1.5, 8/X rotate 000*z}
      sphere {x, 1.5, 8/X rotate 120*z}
      sphere {x, 1.5, 8/X rotate 240*z}
      scale 0.2
      translate <(X/Y)*6-3,-1.5,5>
   }
   #declare X = X+1;
#end

Greetings,

Rune
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In article <3961f972@news.povray.org>, "Rune" <run### [at] inamecom> 
wrote:

> The shape of the falloff curve is irrelevant.
> 
> As long as 2 function remains the same *relative to each other*
> the intersection points remains the same. The code below proves it.

You are right, I was thinking of changing radius, not strength. If you 
render these three blobs you will see what I meant.
blob {
    sphere {< 0, 0.5, 0>, 0.75, strength 1}
    sphere {< 0,-0.5, 0>, 0.75, strength 1}
    threshold 0.25
    texture {
        pigment {color Red}
    }
    translate <-2, 1, 0>
}
blob {
    sphere {< 0, 0.5, 0>, 1, strength 1}
    sphere {< 0,-0.5, 0>, 1, strength 1}
    threshold 0.5
    texture {
        pigment {color Red}
    }
    translate < 0, 1, 0>
}
blob {
    sphere {< 0, 0.5, 0>, 1.5, strength 1}
    sphere {< 0,-0.5, 0>, 1.5, strength 1}
    threshold 0.75
    texture {
        pigment {color Red}
    }
    translate < 2, 1, 0>
}

-- 
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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"Chris Huff" wrote:
> "Rune" wrote:
>
> > The shape of the falloff curve is irrelevant.
>
> You are right, I was thinking of changing radius, not strength.

Yes, radius and strength are two very different things! :-)

BTW, where can I find an example scene that uses your blob pattern?
I can't get it to work.

Greetings,

Rune
--
Updated June 12: http://rsj.mobilixnet.dk
3D images, include files, stereograms, tutorials,
The POV Desktop Theme, The POV-Ray Logo Contest,
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In article <3962116b@news.povray.org>, "Rune" <run### [at] inamecom> 
wrote:

> BTW, where can I find an example scene that uses your blob pattern?
> I can't get it to work.

There are some included with the other sample scenes: bloblattice.pov and
blobpattern.pov. Also, I forgot to allow the "strength" token, so don't 
use "strength". The strength value just immediately follows the radius. 
This will be fixed in the next release of MegaPOVPlus.

-- 
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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"Chris Huff" wrote:
> "Rune" wrote:
>
> > BTW, where can I find an example scene that uses your blob
> > pattern? I can't get it to work.
>
> Also, I forgot to allow the "strength" token, so don't use
> "strength". The strength value just immediately follows the radius.

Um, then it is useless for the my purpose.

> This will be fixed in the next release of MegaPOVPlus.

I try to keep the programs I use down to a minimum, so I only use official
POV-Ray and MegaPov. I don't even know if there's a Windows version of
MegaPOVPlus yet?

Greetings,

Rune
--
Updated June 12: http://rsj.mobilixnet.dk
3D images, include files, stereograms, tutorials,
The POV Desktop Theme, The POV-Ray Logo Contest,
music, 350+ raytracing jokes, and much more!

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In article <396251a9@news.povray.org>, "Rune" <run### [at] inamecom> 
wrote:

> Um, then it is useless for the my purpose.

How does that make it useless? It is just a syntax issue...a keyword 
which is optional in the blob object isn't accepted at all in the blob 
pattern.


> > This will be fixed in the next release of MegaPOVPlus.
> 
> I try to keep the programs I use down to a minimum, so I only use official
> POV-Ray and MegaPov. I don't even know if there's a Windows version of
> MegaPOVPlus yet?

There is one available on my web site, but it is an older one. I haven't 
released the next version, including the blob pattern fixes, yet.

-- 
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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"Chris Huff" wrote:
> "Rune" wrote:
>
> > Um, then it is useless for the my purpose.
>
> How does that make it useless? It is just a syntax issue...
> a keyword which is optional in the blob object isn't accepted
> at all in the blob pattern.

Sorry, I misunderstood you. I never used the strength keyword anyway.
It'll probably do fine then, if just I could get it to work.

> > I don't even know if there's a Windows version of MegaPOVPlus yet?
>
> There is one available on my web site, but it is an older one. I haven't
> released the next version, including the blob pattern fixes, yet.

But the blob pattern is also included in regular MegaPov, and I found the
files you mentioned, so my problem is solved for now. :-)

Greetings,

Rune
--
Updated June 12: http://rsj.mobilixnet.dk
3D images, include files, stereograms, tutorials,
The POV Desktop Theme, The POV-Ray Logo Contest,
music, 350+ raytracing jokes, and much more!

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