POV-Ray : Newsgroups : povray.advanced-users : About the slope pattern Server Time
29 Apr 2024 14:48:06 EDT (-0400)
  About the slope pattern (Message 1 to 3 of 3)  
From: Thomas de Groot
Subject: About the slope pattern
Date: 10 May 2015 10:11:36
Message: <554f6718$1@news.povray.org>
You may have followed the discussion in p.newusers (can't i rotate a 
pigment?).

My question here is: is the described issue with the rotation of a slope 
pattern a bug (my initial thought) or is it not?

Personally, I really don't know.

-- 
Thomas


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From: Le Forgeron
Subject: Re: About the slope pattern
Date: 10 May 2015 11:41:06
Message: <554f7c12$1@news.povray.org>
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Le 10/05/2015 16:11, Thomas de Groot a écrit :
> You may have followed the discussion in p.newusers (can't i rotate
> a pigment?).
> 
> My question here is: is the described issue with the rotation of a
> slope pattern a bug (my initial thought) or is it not?
> 
> Personally, I really don't know.
> 
History, it's all about history.

And overcharging a pattern (there is "<direction vector>" and
"point_at <position vector>" )

In megapov, it was "aoi" pattern (and it was already special too: with
or without a point, the behavior was different)

And to summarise the answer: there is no right answer.

Some might want to reorient the pattern once transformed, and some
might want to keep it as it is; It would need a kind of
"reset_children" option (a warp that appeared in megapov 0.6, now gone)

So far, if you want to rotate the slope pattern, you need to apply the
transformation to the parameters of the slope pattern... but shearing
transformation will never apply as expected (as the value is due to
the normal of the object, so shearing the object also change the normal)

Reorienting the slope direction or point might be easy, but the
control of low & high altitude, as well as low and high slope make
such update very difficult to perform automatically.

Did I say it was an overcharged pattern ? with a direction, the
altitude is another extension of it too!
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From: Thomas de Groot
Subject: Re: About the slope pattern
Date: 11 May 2015 02:58:40
Message: <55505320@news.povray.org>
Thanks for that! I suspected as much and you have confirmed my thoughts. 
Using the slope pattern, we need to be smart and creative. A little 
intellectual challenge. Did I tell you that I love this pattern?

:-)

-- 
Thomas


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