POV-Ray : Newsgroups : povray.binaries.images : First image posting : Re: First image posting Server Time
17 May 2021 19:24:57 EDT (-0400)
  Re: First image posting  
From: Thomas de Groot
Date: 3 May 2021 02:48:11
Message: <608f9cab$1@news.povray.org>
Op 03/05/2021 om 08:36 schreef Thomas de Groot:
> Op 02/05/2021 om 14:11 schreef Bald Eagle:
>> Thomas de Groot <tho### [at] degrootorg> wrote:
>>
>>>> Presumably, this is what all this "mip-mapping" business is about.   
>>>> Has anyone
>>>> ever tried to emulate that process, that we know of?
>>>>
>>> Good question. It would be interesting to try indeed. RoundTuits are
>>> needed however!
>>
>> https://www.youtube.com/watch?v=0flY11lVCwY
>> He covers this briefly in the first 2 minutes.
>>
>> Just shooting from the hip here, but it sounds like a functional 
>> emulation of
>> this would be to start with a very large, high-def version of the 
>> texture and

>> filenames and
>> the texture could probably be automagically sampled at the desired 
>> resolution
>> using a polynomial function like I did in the vortex scene or using a 
>> spline
>> like Ingo is doing.
>>
> By default, a factor 2 scaling is used, I understand. That is not 
> difficult; what is (at least for me) is how to chose the right texture 
> for each render or location in the scene (for instance the background of 
> a chequered plane smoothly grading into the foreground). Well, I have an 
> idea of course, but no time to test it out presently. :-/
> 
>> Maybe there's some kind of MOA (minutes of angle) calculation that 
>> initially
>> gets done to optimally set the different image_map resolutions...?
>>
> Hmm... possibly. I have no idea at this stage however.
> 

And I immediately come back to the matter as I suddenly realise that 
this would be a crucial technique for using the same granite textures 
(forgive me my present obsession with granites) in close foreground 
views and landscape-sized backgrounds. Or wouldn't it? Is mipmapping 
only useful with image_maps? The examples I have seen so far are just 
that. Could it be applied successfully to traditional POV-Ray textures?

-- 
Thomas


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