(The answer to this may be in docs somewhere, but I can't find anything.)

I'm using pure radiosity to light a scene, because an area-light doesn't
look right (and learning quite a lot about radiosity in the process!).
However, I'm using Megapov 1.2.1 on a MacBook ('cos POV-Ray for Mac OS
doesn't work) and I get significantly different results compared to using
POV-Ray 3.6 for the same scene file. My understanding is that, unless you
activate the patches using the #version directive, Megapov should produce
the same output as the version of POV-Ray upon which it is based - 3.6.

If I have a large high-ambient object with no_image, no_reflection and
no_shadow, in Megapov it lights the scene nicely with radiosity. In POV-Ray
3.6, it provides no lighting at all unless I remove the no_image modifier
(inconveniently making the light source visible). Furthermore, optimal
radiosity parameters under 3.6 render differently, indeed poorly, under
Megapov (I have yet to find optimal parameters in the latter case!).

My question, therefore, is: are there differences between the radiosity
implementations, or could I be doing something else wrong?

This is playing havoc with my IRTC entry... :-

Any advice or pointers muchly anticipated!
Bill

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Bill Pragnell wrote:
> 
> If I have a large high-ambient object with no_image, no_reflection and
> no_shadow, in Megapov it lights the scene nicely with radiosity. In POV-Ray
> 3.6, it provides no lighting at all unless I remove the no_image modifier
> (inconveniently making the light source visible). 

MegaPOV splits the no_image flag (which affects both radiosity rays and 
camera rays in official POV-Ray) into no_image and no_radiosity.  This 
is not affected by the #version directive at the moment.  There is no 
way the achieve the same effect in POV-Ray 3.6.

> Furthermore, optimal
> radiosity parameters under 3.6 render differently, indeed poorly, under
> Megapov (I have yet to find optimal parameters in the latter case!).

This seems very unlikely if you are not using any patches.

Christoph

-- 
POV-Ray tutorials, include files, Landscape of the week:
http://www.imagico.de/ (Last updated 15 Oct. 2006)
MegaPOV with mechanics simulation: http://megapov.inetart.net/

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Christoph Hormann <chr### [at] gmxde> wrote:
> MegaPOV splits the no_image flag (which affects both radiosity rays and
> camera rays in official POV-Ray) into no_image and no_radiosity.  This
> is not affected by the #version directive at the moment.  There is no
> way the achieve the same effect in POV-Ray 3.6.
Ah, right. I thought it must be something along those lines.

> > Furthermore, optimal
> > radiosity parameters under 3.6 render differently, indeed poorly, under
> > Megapov (I have yet to find optimal parameters in the latter case!).
> This seems very unlikely if you are not using any patches.
I'm using different image sizes. Can that make a significant difference?

Bill

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