POV-Ray : Newsgroups : moray.win : Moray 'handedness' vs. POV-Ray Server Time
5 Jul 2024 09:13:51 EDT (-0400)
  Moray 'handedness' vs. POV-Ray (Message 1 to 10 of 15)  
Goto Latest 10 Messages Next 5 Messages >>>
From: Mark M  Wilson
Subject: Moray 'handedness' vs. POV-Ray
Date: 28 Aug 2001 14:44:48
Message: <3B8BE895.92D67321@ncsl.dcr.state.nc.us>
I know this is addressed in the POV-ray docs, but I just want to make
sure I'm correctly understanding:  The Z-axis in Moray goes "up and
down" vs. in Povray, where it's "toward" or "away from" the user.  But
also, the direction of rotation is different, right?  What I'm getting
at is this:  


where I *really* want it to be (at least in one of the dimensions) once
saved and exported to a *.pov file, can I just forgo having to add the
rotate statements to the .pov file?  As my example, I'm thinking for
instance of the example Bezier patch in the POV-ray manual.  If I
deliberately orient it "wrong" in Moray as an attempt to compensate for
the different orientation of the axes, will I get what I want when I
render the actual .pov file?  

Did this question make sense to anyone?

And BTW, how do you pronounce Bezier?  Is it "Beh-zee-ay,"
"Bay-zee-ay,"  or something else altogether?

Thanks,
Mark M. Wilson (a Povray and Moray newbie)


Post a reply to this message

From: Warp
Subject: Re: Moray 'handedness' vs. POV-Ray
Date: 28 Aug 2001 18:11:34
Message: <3b8c1716@news.povray.org>
You can't convert a right-handed object to a left-handed object only by
rotating it. You also need to mirror it about an axis.
  Think about your own right hand: No matter how you rotate it, it will
never be an exact copy of your left hand. You would have to mirror your
right hand in order to get your left hand.
  So you need to make a scale <-1,1,1> and a proper rotation in order to
get the same object in POV-Ray.
  (Of course the other solution is to use a right-handed camera in POV-Ray
so that its universe is identical to Moray's.)

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -


Post a reply to this message

From: Daniel Lin
Subject: Re: Moray 'handedness' vs. POV-Ray
Date: 28 Aug 2001 18:37:47
Message: <3b8c1d3b@news.povray.org>
You still haven't answered how to pronounce "Bezier."

--
Me


Post a reply to this message

From: Sander
Subject: Re: Moray 'handedness' vs. POV-Ray
Date: 29 Aug 2001 05:13:29
Message: <MPG.15f6d0afe3dc3a00989846@NEWS.POVRAY.ORG>
In article <3b8c1716@news.povray.org>, Warp says...
>   You can't convert a right-handed object to a left-handed object only by
> rotating it. You also need to mirror it about an axis.
<snip>
How does one mirror about an axis? Shouldn't that be a plane? ;)
-- 
Regards,  Sander


Post a reply to this message

From: Warp
Subject: Re: Moray 'handedness' vs. POV-Ray
Date: 29 Aug 2001 07:39:45
Message: <3b8cd481@news.povray.org>
Sander <san### [at] stolscom> wrote:
: How does one mirror about an axis? Shouldn't that be a plane? ;)

  It depends on how you think about it. You can mirror an object in the
direction of an axis, ie. one axis of the object gets inverted.
  This is what scale <-1,1,1> does basicly...

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -


Post a reply to this message

From: Mark M  Wilson
Subject: Re: Moray 'handedness' vs. POV-Ray
Date: 29 Aug 2001 09:50:45
Message: <3B8CF52D.27742BFA@ncsl.dcr.state.nc.us>
Warp wrote:
> 

>   So you need to make a scale <-1,1,1> and a proper rotation in order to
> get the same object in POV-Ray.

Never occurred to me that you could do a negative scale -- does that
help make a mirror image of a non-symmetrical obj. in a way that merely


>   (Of course the other solution is to use a right-handed camera in POV-Ray
> so that its universe is identical to Moray's.)

That sounds really interesting -- I'll have to check it out.  Is the
syntax for doing a RH camera addressed in the POVray manual?

Thanks for your input, and like Daniel said, any clue how to pronounce
Bezier, or is it one of those words you've never had occasion to say
outloud, so you're no more certain than me?  ;-)

--Mark


 
> --
> #macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
> rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
> ],13),8)-3,10>#end blob{N(array[6]{11117333955,
> 7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -


Post a reply to this message

From: Ken
Subject: Re: Moray 'handedness' vs. POV-Ray
Date: 29 Aug 2001 10:00:48
Message: <3B8CF64E.272F87BF@pacbell.net>
"Mark M. Wilson" wrote:

> Thanks for your input, and like Daniel said, any clue how to pronounce
> Bezier, or is it one of those words you've never had occasion to say
> outloud, so you're no more certain than me?  ;-)

Bez-ee-ur - like busier with an e. Works for me and I'm sticking with it.

-- 
Ken Tyler


Post a reply to this message

From: Mark M  Wilson
Subject: Re: Moray 'handedness' vs. POV-Ray
Date: 29 Aug 2001 10:04:14
Message: <3B8CF855.D8F94A5D@ncsl.dcr.state.nc.us>
Hmph, I was sure it sounded French. ;-)
-Mark

Ken wrote:
> 
> "Mark M. Wilson" wrote:
> 
> > Thanks for your input, and like Daniel said, any clue how to pronounce
> > Bezier, or is it one of those words you've never had occasion to say
> > outloud, so you're no more certain than me?  ;-)
> 
> Bez-ee-ur - like busier with an e. Works for me and I'm sticking with it.
> 
> --
> Ken Tyler


Post a reply to this message

From: Warp
Subject: Re: Moray 'handedness' vs. POV-Ray
Date: 29 Aug 2001 10:13:53
Message: <3b8cf8a0@news.povray.org>
Mark M. Wilson <mmw### [at] ncsldcrstatencus> wrote:
: Never occurred to me that you could do a negative scale -- does that
: help make a mirror image of a non-symmetrical obj. in a way that merely


  Again, think about your hands: No matter how you ROTATE your right hand,
it will never be identical to your left hand. So rotating doesn't help.
  A negative scaling just mirrors the object in the direction of the axis
(internally it doesn't differ at all from a regular positive scale).

: That sounds really interesting -- I'll have to check it out.  Is the
: syntax for doing a RH camera addressed in the POVray manual?

  What you have to do to make a right-handed camera is to, surprise surprise,
mirror the camera about an axis.
  For more details, see
http://www.students.tut.fi/~warp/povVFAQ/morayVFAQ.html#handedness

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -


Post a reply to this message

From: Ken
Subject: Re: Moray 'handedness' vs. POV-Ray
Date: 29 Aug 2001 10:18:11
Message: <3B8CFA61.B3DF64D0@pacbell.net>
"Mark M. Wilson" wrote:
> 
> Hmph, I was sure it sounded French. ;-)

When in Rome...

-- 
Ken Tyler


Post a reply to this message

Goto Latest 10 Messages Next 5 Messages >>>

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.