POV-Ray : Newsgroups : povray.general : Trace()? Server Time
7 Aug 2024 11:19:36 EDT (-0400)
  Trace()? (Message 21 to 30 of 31)  
<<< Previous 10 Messages Goto Latest 10 Messages Next 1 Messages >>>
From: Jon A  Cruz
Subject: Re: Trace()?
Date: 15 Nov 2001 11:49:23
Message: <3BF3F1A7.D25648DA@geocities.com>
Nekar Xenos wrote:

> I'd love to get to conversation level with ancient Greek but I don't know anyone
> else that speaks the language...

Ask around of the staff at some Protestant churches in your area. At least here in
the states that is a language usually learned in seminary.

--
Jon A. Cruz
http://www.geocities.com/joncruz/action.html


Post a reply to this message

From: Jon A  Cruz
Subject: Re: Trace()?
Date: 15 Nov 2001 11:50:47
Message: <3BF3F1FB.5C9F9FB7@geocities.com>
Arthur Flint wrote:

> Bill DeWitt scribis news:3bf277ca$1@news.povray.org:
>
> >     If we had one history or origin or if it were made instead of
> >     grown, it
> > would not be so confusing.
> >
>
> Try a "made" language then. Several exist. Anything from Klingon to
> Atlantian. There are several clubs that for the "speaking" population to
> get together at/with and have fun.

You forgot to mention the languages that Tolkien made. His history for them
is quite interesting also.


--
Jon A. Cruz
http://www.geocities.com/joncruz/action.html


Post a reply to this message

From: Bill DeWitt
Subject: Re: Trace()?
Date: 15 Nov 2001 11:58:22
Message: <3bf3f42e$1@news.povray.org>
"Arthur Flint" <mra### [at] chesapeakenet> wrote :
>
> My favorite is Esperanto.

    That's on my list. I hear it is fairly simple to learn if you are a
Latin-based native speaker.


Post a reply to this message

From: Arthur Flint
Subject: Re: Trace()?
Date: 15 Nov 2001 20:44:25
Message: <Xns915AD2F00B9FCmrartchesapeakenet@204.213.191.226>
Bill DeWitt scribis news:3bf3f42e$1@news.povray.org:

> 
> "Arthur Flint" <mra### [at] chesapeakenet> wrote :
>>
>> My favorite is Esperanto.
> 
>     That's on my list. I hear it is fairly simple to learn if you are a
> Latin-based native speaker.
> 
Here is a translation (of sorts) of your comment.
Tio estas je mia listo. Mi audas ke Esperanto estas falica por lerni,se vi 
estas Latinderivite indig^ena parolulo.

The language uses an accusitive case for the recipent of the action. So in 
one instance " a male dog" could be spelled "hundo" and in another, 
"hundon". Means you have to listen verry carefully to how things are said 
to catch the meaning.

-- 
G^is poste, Arto.
(until later, Art)


Post a reply to this message

From: Bill DeWitt
Subject: Re: Trace()?
Date: 15 Nov 2001 22:52:49
Message: <3bf48d91$1@news.povray.org>
"Arthur Flint" <mra### [at] chesapeakenet> wrote in message
news:Xns### [at] 204213191226...
> Bill DeWitt scribis news:3bf3f42e$1@news.povray.org:
>
> >
> > "Arthur Flint" <mra### [at] chesapeakenet> wrote :
> >>
> >> My favorite is Esperanto.
> >
> >     That's on my list. I hear it is fairly simple to learn if you are a
> > Latin-based native speaker.
> >
> Here is a translation (of sorts) of your comment.
> Tio estas je mia listo. Mi audas ke Esperanto estas falica por lerni,se vi
> estas Latinderivite indig^ena parolulo.

    Well, they gotta fix that ^ business... Other than that, as is true of
french italian and spanish, you can pick out root words and get most of the
meaning.

> --
> G^is poste, Arto.
> (until later, Art)


Post a reply to this message

From: Peter Popov
Subject: Re: Trace()?
Date: 16 Nov 2001 00:36:18
Message: <i899vtgbsahg9ct49iq0asrahjphpmo8na@4ax.com>
On 15 Nov 2001 20:44:25 -0500, Arthur Flint <mra### [at] chesapeakenet>
wrote:

>Tio estas je mia listo. Mi audas ke Esperanto estas falica por lerni,se vi 
>estas Latinderivite indig^ena parolulo.

A strange mixture of Spanish-, Italian-, Romanian- and Latin-like
ingredients. All Roman languages. BTW should "Latinderivite" really be
a single word?


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg


Post a reply to this message

From: Arthur Flint
Subject: Re: Trace()?
Date: 16 Nov 2001 03:59:47
Message: <Xns915B289E4AA1Amrartchesapeakenet@204.213.191.226>
Peter Popov scribis news:i899vtgbsahg9ct49iq0asrahjphpmo8na@4ax.com:
> A strange mixture of Spanish-, Italian-, Romanian- and Latin-like
> ingredients. 
All true, with some German and Greek roots in there too.

>All Roman languages. BTW should "Latinderivite" really be a single word?
It could well be as we wern't all too sure how to construct that one. Some 
words are constructed by concatanation.
i.e. Mang^o "food" + c^ambro "room" = mang^oc^ambro "dinning room"

-- 
Gis posta, Arto.


Post a reply to this message

From: Arthur Flint
Subject: Re: Trace()?
Date: 16 Nov 2001 04:04:35
Message: <Xns915B296E9A1C3mrartchesapeakenet@204.213.191.226>
Bill DeWitt scribis news:3bf48d91$1@news.povray.org:
>     Well, they gotta fix that ^ business... Other than that, as is true
>     of french italian and spanish, you can pick out root words and get     
>     most of the meaning.
> 
It might look better if you could see the characters in proper format.
The "^" should be over the character that it comes after. Until all the 
world lives with unicode, that is the best I could do. There is c^, g^, h^, 
s^, and a u with a small symbole over it.



-- 
Gis posta, Arto.


Post a reply to this message

From: Bill DeWitt
Subject: Re: Trace()?
Date: 16 Nov 2001 08:04:29
Message: <3bf50edd@news.povray.org>
Follow-up set

"Arthur Flint" <mra### [at] chesapeakenet> wrote in message
news:Xns### [at] 204213191226...
> Bill DeWitt scribis news:3bf48d91$1@news.povray.org:
> >     Well, they gotta fix that ^ business... Other than that, as is true
> >     of french italian and spanish, you can pick out root words and get
> >     most of the meaning.
> >
> It might look better if you could see the characters in proper format.
> The "^" should be over the character that it comes after. Until all the
> world lives with unicode, that is the best I could do. There is c^, g^,
h^,
> s^, and a u with a small symbole over it.

    I went through and set up two letter combinations for every phoneme I
could find and pronounce (for my own constructed language), using standard
American English character pronunciations. It seems like the folk who
developed Esperanto could have done something similar.


Post a reply to this message

From: Mike Williams
Subject: Re: Trace()?
Date: 22 Nov 2001 13:01:01
Message: <yceboGAMPH$7Ew7m@econym.demon.co.uk>
Wasn't it Mahalis who wrote:

>Could anyone explain to me exactly how one uses the trace() function to
>detect object collisions? The docs say that 'trace() can be used to detect
>the exact point a ray intersects a surface' and then gives a perfectly
>incomprehensible (to me at least) example.

It occurred to me that it ought to be possible to detect whether two
convex objects had collided by tracing in both directions along the line
that joins their centres.

Consider two convex objects that are not touching. As we look along the
line that joins their centres we encounter the significant points in the
following order:-
        Centre of object 1
        Surface of object 1
        Surface of object 2
        Centre of object 2

If the objects are moved closer so that they intersect, then the order
changes to
        Centre of object 1
        Surface of object 2
        Surface of object 1
        Centre of object 2

(With concave objects all bets are off. It's possible for two concave
objects to touch at the ends while there is still a gap between them
along the line that joins their centres).


I came up with code that looks like this

// trace object2 from the centre of object 1 and vice verca
#declare Surface2 = trace(Object2, Centre1, (Centre2-Centre1));
#declare Surface1 = trace(Object1, Centre2, (Centre1-Centre2));

// The objects intersect if Surface2 is nearer to Centre1
// than Surface1 is
#if (vlength(Surface2-Centre1) < vlength(Surface1-Centre1))
  #debug "They intersect\n"
#else
  #debug "They don't\n"
#end

But that code can sometimes give the wrong answer if the objects overlap
to such an extent that the centre of one lies inside the surface of the
other. For example, if the centres are very close the order might be
        Surface of Object 1
        Centre of Object 1
        Centre of Object 2
        Surface of Object 2
and the surfaces could be at any distance.



I think that this works

// trace object2 from the centre of object 1 and vice verca
#declare Surface2 = trace(Object2, Centre1, (Centre2-Centre1));
#declare Surface1 = trace(Object1, Centre2, (Centre1-Centre2));

// The objects intersect if the centre-centre distance
// is less than the sum of the centre-surface distances
#if ((vlength(Centre2-Centre1)  < (vlength(Surface1-Centre1) +     
     vlength(Surface2-Centre2)))) 
  #debug "They intersect\n"
#else
  #debug "They don't\n"
#end

-- 
Mike Williams
Gentleman of Leisure


Post a reply to this message

<<< Previous 10 Messages Goto Latest 10 Messages Next 1 Messages >>>

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