I have a very minimal scene with a blob that does not behave like I 
expect it.
Basically it is the first tutorial scene from 3.6.1 with two extra 
spheres added above the originals. It seems to render some artifacts 
where the top spheres connect to the bottom ones.

I am new to POV-Ray and don't know the right way to do this. But I 
expect just dropping the scene files into p.b.scene-files would not be 
the way to go so I thought I'd ask here.

Thanks for your time,
Rob

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"Rob Hoopman" <rob### [at] tunanl> wrote in message
news:3D6### [at] tunanl...
> I am new to POV-Ray and don't know the right way to do this. But I
> expect just dropping the scene files into p.b.scene-files would not be
> the way to go so I thought I'd ask here.

Have a read of Rune's blob tutorial:
http://runevision.com/3d/blobs/blobs.asp

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"Rob Hoopman" <rob### [at] tunanl> wrote in message
news:3D6### [at] tunanl...
> I have a very minimal scene with a blob that does not behave like I
> expect it.
> Basically it is the first tutorial scene from 3.6.1 with two extra
> spheres added above the originals. It seems to render some artifacts
> where the top spheres connect to the bottom ones.
>
> I am new to POV-Ray and don't know the right way to do this. But I
> expect just dropping the scene files into p.b.scene-files would not be
> the way to go so I thought I'd ask here.

A short, concise, sample of a problem scene file is fine posted as text here
in p.g.

Have you already tried sturm in the blob statement? If not then that's
something to check on. It could be a shadows on the surface normals thing,
the blob equation causing erratic changes in it. If that doesn't seem to be
it a posting of a render showing it would be good to see, at p.b.i. or at
least the blob + camera + light script so someone else besides you can
render it.

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Alan Holding wrote:
> "Rob Hoopman" <rob### [at] tunanl> wrote in message
> news:3D6### [at] tunanl...
> 
>>I am new to POV-Ray and don't know the right way to do this. But I
>>expect just dropping the scene files into p.b.scene-files would not be
>>the way to go so I thought I'd ask here.
> 
> 
> Have a read of Rune's blob tutorial:
> http://runevision.com/3d/blobs/blobs.asp
> 
> 

I did, allthough his site down at the moment, well not so much down as 
having problems connecting to the database.


Rob

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Blobs have artifacts, sometimes. This is still a problem with POV, but you
could try to move each blob component away from the others. They must not be
very close to each other.

Regards,
Hugo

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hughes b wrote:
> "Rob Hoopman" <rob### [at] tunanl> wrote in message
> news:3D6### [at] tunanl...
> 
>>I have a very minimal scene with a blob that does not behave like I
>>expect it.
>>Basically it is the first tutorial scene from 3.6.1 with two extra
>>spheres added above the originals. It seems to render some artifacts
>>where the top spheres connect to the bottom ones.
>>
>>I am new to POV-Ray and don't know the right way to do this. But I
>>expect just dropping the scene files into p.b.scene-files would not be
>>the way to go so I thought I'd ask here.
> 
> 
> A short, concise, sample of a problem scene file is fine posted as text here
> in p.g.
> 
> Have you already tried sturm in the blob statement? If not then that's
> something to check on. It could be a shadows on the surface normals thing,
> the blob equation causing erratic changes in it. If that doesn't seem to be
> it a posting of a render showing it would be good to see, at p.b.i. or at
> least the blob + camera + light script so someone else besides you can
> render it.
> 
> 

I had a look at the docs regarding the sturm keyword and don't think it 
would solve my problem. (Allthough I must say it is not exactly clear to 
what values I would have to set it. What is a "boolean float value", 
does this mean any float value that is not zero evaluates to true?)

If it helps I can also post an image to p.b.i.

Rob

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> camera {
>   angle 15
>   location <0,2,-10>
>   look_at <0,0,0>
> }

Narrow camera angles can make stuff show up wrong... try it with one like this

camera {
  location <0,0,-2.25>
  look_at <0,0,0>
}

--
Tim Attwood

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I tested your scene and fiddled with the variables (if you remove "angle"
from camera, the problem will disappear in this particular case) but
basically, it's caused by the current limitation of blobs.  The blob bugs
were not fixed in POV3.5. If you wish, you can read about them here:

http://news.povray.org/search/advanced/?s=blob&bug&b=Search&g=povray.beta-te
st&a=0&p=0


- Hugo

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n.t.

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Rob Hoopman wrote:
> Alan Holding wrote:
>> Have a read of Rune's blob tutorial:
>> http://runevision.com/3d/blobs/blobs.asp
>
> I did, allthough his site down at the moment,
> well not so much down as having problems
> connecting to the database.

What the...!??

I was not aware of that. I'll have to look into that. Problem is that I
don't have much time right now, but I'll see what I can do.

Rune
--
3D images and anims, include files, tutorials and more:
rune|vision:  http://runevision.com (updated July 12)
POV-Ray Ring: http://webring.povray.co.uk

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