Me again,
just little changes in the formulas, I delete all pi and the torus is 
better.

#declare F1= function(u,v) 
{sin(u)*(7.0+cos((u/3.0)-(2.0*v))+2.0*cos((u/3.0)+(v))) };
#declare F2= function(u,v) 
{cos(u)*(7.0+cos((u/3.0)-(2.0*v))+2.0*cos((u/3.0)+(v))) };
#declare F3= function(u,v) { sin((u/3.0)-(2.0*v))+2.0*sin((u/3.0)+(v)) };


Lionel.
-- 
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---

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hi Alain,

On 13/03/2014 00:21, Alain wrote:
> You should go straight to version 3.7. That way, you won't need to
> UNlearn some of those "ropes"...

hmm, are you saying that the syntax for /existing/ SDL statements has
changed from 3.6 to 3.7?

> It's somewhat faster, can take advantage of all cores on modern
> computer, have several bug fixes, introduce some new features like
> subsurface light transport and high dynamic range images as source
> and output option.
> It also have some improvements for focal blur and antialiasing.
> The irid code is totaly redone as it was broken in version 3.6 ...

I might (for now) miss out on bug fixes and new features, but that's ok
for a learner; wrt multiple cores - I run Povray on a VM which is
limited to 'see' 1 cpu and 1G RAM.

Post a reply to this message

hi Lionel,

On 13/03/2014 11:46, FractRacer wrote:
> I have modified Ingo's file like this:

On 13/03/2014 11:46, FractRacer wrote:
> just little changes in the formulas, I delete all pi and the torus is
> better.

merci bien, Lionel.  I'll probably keep that file modification.

Post a reply to this message

> hi Alain,
>
> On 13/03/2014 00:21, Alain wrote:
>> You should go straight to version 3.7. That way, you won't need to
>> UNlearn some of those "ropes"...
>
> hmm, are you saying that the syntax for /existing/ SDL statements has
> changed from 3.6 to 3.7?

Some feature work in a slightly different way.
Some features have some alternative or optional syntax, like back side 
illumination that is invoked be using 2 parameters for the diffuse value.
There are some bug fixes.
There are several workarounds that are no longer needed, of may actualy 
cause some problems.
There are HUGE changes with radiosity.
Focal blur have been revamped and now work along with regular 
antialiasing. It's also significatively faster.
The paremeters for irid work differently: They are now more closely 
related to actual physical properties.
If you try to render some newer scenes that use new features that you 
can find on the forums, it may abort with some error if you are still 
using version 3.6.

>
>> It's somewhat faster, can take advantage of all cores on modern
>> computer, have several bug fixes, introduce some new features like
>> subsurface light transport and high dynamic range images as source
>> and output option.
>> It also have some improvements for focal blur and antialiasing.
>> The irid code is totaly redone as it was broken in version 3.6 ...
>
> I might (for now) miss out on bug fixes and new features, but that's ok
> for a learner; wrt multiple cores - I run Povray on a VM which is
> limited to 'see' 1 cpu and 1G RAM.
>

Version 3.6 NOT OK for a learner :( At least, it's no longer OK.

The learning curve is the same for both versions. Even if your VM 
environment only expose a single CPU/core, there is no reason to stick 
with version 3.6. Version 3.7 is the current OFFICIAL release.



Alain

Post a reply to this message

>> hi Alain,
>>
>> On 13/03/2014 00:21, Alain wrote:
>>> You should go straight to version 3.7. That way, you won't need to
>>> UNlearn some of those "ropes"...
>>
>> hmm, are you saying that the syntax for /existing/ SDL statements has
>> changed from 3.6 to 3.7?
>
> Some feature work in a slightly different way.
> Some features have some alternative or optional syntax, like back side
> illumination that is invoked be using 2 parameters for the diffuse value.
> There are some bug fixes.
> There are several workarounds that are no longer needed, of may actualy
> cause some problems.
> There are HUGE changes with radiosity.
> Focal blur have been revamped and now work along with regular
> antialiasing. It's also significatively faster.
> The paremeters for irid work differently: They are now more closely
> related to actual physical properties.
> If you try to render some newer scenes that use new features that you
> can find on the forums, it may abort with some error if you are still
> using version 3.6.
>
>>
>>> It's somewhat faster, can take advantage of all cores on modern
>>> computer, have several bug fixes, introduce some new features like
>>> subsurface light transport and high dynamic range images as source
>>> and output option.
>>> It also have some improvements for focal blur and antialiasing.
>>> The irid code is totaly redone as it was broken in version 3.6 ...
>>
>> I might (for now) miss out on bug fixes and new features, but that's ok
>> for a learner; wrt multiple cores - I run Povray on a VM which is
>> limited to 'see' 1 cpu and 1G RAM.
>>
>
> Version 3.6 NOT OK for a learner :( At least, it's no longer OK.
>
> The learning curve is the same for both versions. Even if your VM
> environment only expose a single CPU/core, there is no reason to stick
> with version 3.6. Version 3.7 is the current OFFICIAL release.
>
>
>
> Alain

By the way, my antiquated computer have only a single CPU, and after I 
upgraded to version 3.7 there is NO idea of ever turning back. It works 
SO much beter!


Alain

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hi Lionel and Alain,

to follow up, the scene below uses the parametric directly.

Alain's bounding box guess was pretty close (I've added a
frame to show it), I had expected a much smaller object.

----------<snip>----------

// umbilic torus

#version 3.6;

#include "colors.inc"
#include "shapes.inc"

light_source { <100,100,-100> color White }

camera {
  location <0,0,-30>
  look_at <1,-1,0>
}


#declare oUmbilic = parametric {
  function {sin(u)*(7+cos((u/3)-(2*v))+2*cos((u/3)+v))},
  function {cos(u)*(7+cos((u/3)-(2*v))+2*cos((u/3)+v))},
  function {sin((u/3)-(2*v))+2*sin((u/3)+v)}
  <0,0>,<2*pi,2*pi>
  contained_by { box { <-10,-10,-3>, <10,10,3> } }
  accuracy .0001
  precompute 15 x,y,z
}


union {

  object { oUmbilic pigment { Blue } }

  object {
    Wire_Box_Union(<-10.1,-10.1,-3.1>,<10.1,10.1,3.1>,.05)
    pigment { Red }
  }

  rotate -z*15
  rotate x*30
  rotate y*clock*360
}

----------<snip>----------

thank you both.

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