Hi guys, i'm trying to morph two objects and I was wondering if anyone knows
of a tutorial that shows how to morph two objects, let's say morphing a box
into a sphere, something like that. (just to have an idea.)

Any hints?

Thanks in advance

Fidel.

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On Tue, 06 Aug 2002 19:48:48 +0100, Fidel viegas
<fid### [at] artrecognitioncouk> wrote:

>Hi guys, i'm trying to morph two objects and I was wondering if anyone knows
>of a tutorial that shows how to morph two objects, let's say morphing a box
>into a sphere, something like that. (just to have an idea.)

POV-Ray doesn't support morphing directly. In order to morph between
two objects, they have to be discretized into small finite-accuracy
entities such as triangles, polygons, NURBS etc, and in POV, objects
are mathematical entities described by equations and functions, so
morphing between them is rather hard.

For the case of morphing between a sphere and a box, you have several
options:

1) meshes or patches
2) isosurfaces
3) superellipsoids

The latter two are rather easy to do, with the third one yielding the
best result, but a) it can not represent a cube perfectly well and b)
it is limited to the shapes a superellipsoid can take. 2) is a nice
choice in general but it is more along the lines of cross-dissolving
rather than true morphing (i.e. no true warping is performed). 1) is
required for that, but it's rather hard to do.


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

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"Peter Popov" wrote:
> 2) is a nice
> choice in general but it is more along the lines of cross-dissolving
> rather than true morphing (i.e. no true warping is performed).

Couldn't this somehow be done by transforming into direction of gradient
when < threshold and -gradient when > threshold?
Would that look like morphing or just give a strange looking very slow
rendering thing?

Simon

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I have done many dozens of " morphs" between two isosurfaces, but indeed,
"cross-dissolving" (one image fades out as the other fades in) is a better
term. In most cases, you never actually see two images, just the net
"product" of the two functions, so maybe that will actually get you what you
want.

(untested)
#declare SP = function {f_sphere(x,y,z, 1) } ;
#declare RB = function {f_rounded_box(x,y,z, 0,1,1,1)} ;
#declare MRF = function {(SP(x,y,z)*clock) + (RB(x,y,z) * (1-clock))   } ;

Use that in an isosurface and you will get the idea...
D.


"Fidel viegas" <fid### [at] artrecognitioncouk> wrote in message
news:B975D89F.19F1%fid### [at] artrecognitioncouk...
> Hi guys, i'm trying to morph two objects and I was wondering if anyone
knows
> of a tutorial that shows how to morph two objects, let's say morphing a
box
> into a sphere, something like that. (just to have an idea.)
>
> Any hints?
>
> Thanks in advance
>
> Fidel.
>

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Hello guys,

Thanks for the update.
I can try the later alternative, but I think it would be easier to render
the objects separately and then use a morphing utility to morph the images.

I just thought that would be possible with povray directly. I am going to
try Dennis approach, if that doesn't work, i'll just render them separately
and use a morphing software.
 
Once again thanks for the tips.

Fidel.

in article 3d508b9f$1@news.povray.org, Dennis Miller at dhm### [at] attbicom
wrote on 7/8/02 3:51 am:

> I have done many dozens of " morphs" between two isosurfaces, but indeed,
> "cross-dissolving" (one image fades out as the other fades in) is a better
> term. In most cases, you never actually see two images, just the net
> "product" of the two functions, so maybe that will actually get you what you
> want.
> 
> (untested)
> #declare SP = function {f_sphere(x,y,z, 1) } ;
> #declare RB = function {f_rounded_box(x,y,z, 0,1,1,1)} ;
> #declare MRF = function {(SP(x,y,z)*clock) + (RB(x,y,z) * (1-clock))   } ;
> 
> Use that in an isosurface and you will get the idea...
> D.
> 
> 
> "Fidel viegas" <fid### [at] artrecognitioncouk> wrote in message
> news:B975D89F.19F1%fid### [at] artrecognitioncouk...
>> Hi guys, i'm trying to morph two objects and I was wondering if anyone
> knows
>> of a tutorial that shows how to morph two objects, let's say morphing a
> box
>> into a sphere, something like that. (just to have an idea.)
>> 
>> Any hints?
>> 
>> Thanks in advance
>> 
>> Fidel.
>> 
> 
>

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On Tue, 06 Aug 2002 19:48:48 +0100, Fidel viegas
<fid### [at] artrecognitioncouk> wrote:
> Any hints?

You can be interested in
http://news.povray.org/fiq7cughd3561tlt8kb7u14und8q6i0os5%404ax.com

ABX

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Hello ABX,

That is really wicket. How did you do that? Was all of that done on povray?
Do you have a tutorial on how to do that?

Thanks in advance

Fidel.

in article 9ao1luktnn8jmeii4n4cldg0n3ko1f0vvg@4ax.com, ABX at
abx### [at] babilonorg wrote on 7/8/02 9:59 am:

> On Tue, 06 Aug 2002 19:48:48 +0100, Fidel viegas
> <fid### [at] artrecognitioncouk> wrote:
>> Any hints?
> 
> You can be interested in
> http://news.povray.org/fiq7cughd3561tlt8kb7u14und8q6i0os5%404ax.com
> 
> ABX

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On Wed, 07 Aug 2002 12:15:03 +0100, Fidel viegas
<fid### [at] artrecognitioncouk> wrote:
> Hello ABX,

Hello Fidel,

> That is really wicket. How did you do that?

Exactly the same way as Dennis Miller wrote it in this thread. Averaging two
shape-functions with clock as wieghts and using it in isosurface. Also
material settings were averaged similiar. For shapes I used functions from my
iso_chars addition to iso_csg library.

> Was all of that done on povray?

Yes. Becouse of slowness it was rendered with 3 or 4 machines with various
radiosity settings (for tests) and therefore there is some flickering.

> Do you have a tutorial on how to do that?

No. If there is not enough informations above ask particular thing since I
have some other tasks at this moment :-(

ABX

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