> This should be possible by using it as a blob pattern in a pigment
> isosurface function, and displacing the isosurface.

I hadn't thought of that. Good idea. Well, of course, you created it, so it
was obvious to you, I'm sure. :)

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"Chris Huff" wrote:
> "Tony[B]" wrote:
>
> > And I feel that we should be seeing some true displacement,
> > not just fake normals.
>
> This should be possible by using it as a blob pattern in a
> pigment isosurface function, and displacing the isosurface.

That originally was my plan, but it turned out not to work very well.

The problem is that the blob has blob elements of greatly varying strengths.
So some parts of the blob is greatly affected by displacement, while other
parts are almost not affected at all.

Another problem is that not all parts of the fish should be affected equally
much. The back fin, the teeth and the pupils should not be displaced very
much, while larger chunks of clay should get big bumps. That is almost
impossible to achieve.

So to sum up: The model is displaced unevenly in uncontrollable ways, but I
need it to be displaced unevenly in a controllable way. I don't think that's
possible.

Rune
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In article <3a9e7e79@news.povray.org>, "Rune" <run### [at] inamecom> 
wrote:

> So to sum up: The model is displaced unevenly in uncontrollable ways, 
> but I need it to be displaced unevenly in a controllable way. I don't 
> think that's possible.

It *is* possible to have displacement be independant of gradient...just 
displace the coordinates you give to the blob function, instead of 
adding to/subtracting from the function. Use 3 displacement functions 
with outputs from -1 to 1, each one offset a bit so it doesn't 
synchronize with the others, and add their results to the blob function 
coordinates, multiplying by another function controlling the strength of 
the displacement.

function {
    BlobFunc(
        DispFuncX(x, y, z)*StrengthFunc(x, y, z) + x,
        DispFuncY(x, y, z)*StrengthFunc(x, y, z) + y,
        DispFuncZ(x, y, z)*StrengthFunc(x, y, z) + z
    )
}

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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In article <3a9d4d14@news.povray.org>, "Rune" <run### [at] inamecom> 
wrote:

> Oh I see - I thought lighting and lightning were spelled the same way, but
> they're not!
> 
> Lightning lighting lightning lighting lightning lighting.
> 
> I feel enlightninged now!

Ahem, "enlightened". Being "enlightninged" sounds rather painful, and 
potentially fatal.

"lighting": illumination. Position, brightness, color, etc. of lights in 
a scene.

"lightening": making lighter in color, increasing the amount of light.

"lightning": atmospheric discharges of high-voltage static electricity. 
Lightning has a lightening effect on the lighting of a scene, but is 
otherwise unrelated.

BTW, textures.inc also got this wrong, with the Lightening1 and 
Lightening2 textures, so don't feel too bad. It's called "English". ;-)

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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"Chris Huff" wrote:
> "Rune" wrote:
>
> > Oh I see - I thought lighting and lightning were spelled
> > the same way, but they're not!
> >
> > Lightning lighting lightning lighting lightning lighting.
> >
> > I feel enlightninged now!
>
> Ahem, "enlightened". Being "enlightninged" sounds rather
> painful, and potentially fatal.

I know, I know! The last line was a joke! :)

Rune
--
\ Include files, tutorials, 3D images, raytracing jokes,
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\ all be found at http://rsj.mobilixnet.dk (updated January 28)
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"Chris Huff" wrote:
> It *is* possible to have displacement be independant of
> gradient... just displace the coordinates you give to the
> blob function, instead of adding to/subtracting from the
> function.

Aha, I didn't know that.

> Use 3 displacement functions with outputs from -1 to 1,
> each one offset a bit so it doesn't synchronize with the
> others

It sounds to me like a displacement pattern value will displace the surface
in a specific direction rather than displacing it in the direction of the
surface normal (or vnormalized gradient vector). That makes me think that it
is not useful for displacing a surface by a specific and detailed 3D solid
pattern. Is that correct? Maybe there's another method for handling this?

Rune
--
\ Include files, tutorials, 3D images, raytracing jokes,
/ The POV Desktop Theme, and The POV-Ray Logo Contest can
\ all be found at http://rsj.mobilixnet.dk (updated January 28)
/ Also visit http://www.povrayusers.org

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In article <3a9ecbf4@news.povray.org>, "Rune" <run### [at] inamecom> 
wrote:

> It sounds to me like a displacement pattern value will displace the 
> surface in a specific direction rather than displacing it in the 
> direction of the surface normal (or vnormalized gradient vector). 
> That makes me think that it is not useful for displacing a surface by 
> a specific and detailed 3D solid pattern. Is that correct? Maybe 
> there's another method for handling this?

Correct, it works more like the first type of displace warp (which 
actually may be a more efficient way of doing it...), pushing the 
surface in a direction depending only on it's position.
I'm not sure what you mean by "displacing a surface by a specific and 
detailed 3D solid pattern", could you explain what you want?

Maybe another type of displace warp, using the gradient to determine the 
direction of displacement, and another pattern to define the amount of 
displacement. Also, the ability to use a spline as a "float_map" instead 
of a pigment.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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Chris Huff wrote:
> 
> Maybe another type of displace warp, using the gradient to determine the
> direction of displacement, and another pattern to define the amount of
> displacement. 

I think that could approximately be done by using a pigment_map
construction or a function pigment combining both patterns, not totally
sure about it though.

> Also, the ability to use a spline as a "float_map" instead
> of a pigment.

Could you explain more detailed?

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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In article <3A9F5FAB.EC816B6E@gmx.de>, Christoph Hormann 
<chr### [at] gmxde> wrote:

> I think that could approximately be done by using a pigment_map
> construction or a function pigment combining both patterns, not totally
> sure about it though.

I don't think so...well, you could do it all by hand, but it would be 
extremely tedious, even using the blob_pigment feature. A modification 
of the displace warp would be faster and tremendously easier.


> > Also, the ability to use a spline as a "float_map" instead
> > of a pigment.
> 
> Could you explain more detailed?

The displace warp uses the gradient of the grayscale value of the color 
of a pigment to determine the direction and amount of warping to do. 
Instead of taking a pigment (pattern + color_map), it will be able to 
take a pattern and spline, and get the float value directly instead of 
converting colors to floats. In other words, using a spline {} as a 
"float_map {}", mapping float values to pattern values.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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Chris Huff wrote:
> 
> The displace warp uses the gradient of the grayscale value of the color
> of a pigment to determine the direction and amount of warping to do.
> Instead of taking a pigment (pattern + color_map), it will be able to
> take a pattern and spline, and get the float value directly instead of
> converting colors to floats. In other words, using a spline {} as a
> "float_map {}", mapping float values to pattern values.
> 

Wouldn't a spline wavetype for patterns do that?

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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