I want add/ask something

first:

why assign_XXXXs (vector , matrices) with memcpy
are not used in functions from matrices.c ?
as I remember from assembler, loops with assigment
are slower than fast memory transfer

second:

perhaps this is not important for advenced pov-programmers but...

All_XXX_Intersections()

why this not return ALL if there is ALL in name ?

is this proper name for function?
for beginner this makes trouble, belive me :-)

ABX

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On Mon, 11 Dec 2000 12:22:48 +0100, Wlodzimierz ABX Skiba wrote:
>All_XXX_Intersections()
>
>why this not return ALL if there is ALL in name ?

It should return all, but meshes and some other objects are exceptions to
the rule, usually for speed considerations.  Anything you can use in CSG 
should definitely return all.

-- 
Ron Parker   http://www2.fwi.com/~parkerr/traces.html
My opinions.  Mine.  Not anyone else's.

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Ron Parker wrote in message ...
> >All_XXX_Intersections()
> >
> >why this not return ALL if there is ALL in name ?
>
> It should return all, but meshes and some other objects are exceptions to
> the rule, usually for speed considerations.  Anything you can use in CSG
> should definitely return all.


hmm, but everything returns only positive vales of depth
this isn't all

ABX

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On Mon, 11 Dec 2000 13:57:57 +0100, Wlodzimierz ABX Skiba wrote:
>Ron Parker wrote in message ...
>> >All_XXX_Intersections()
>> >
>> >why this not return ALL if there is ALL in name ?
>>
>> It should return all, but meshes and some other objects are exceptions to
>> the rule, usually for speed considerations.  Anything you can use in CSG
>> should definitely return all.
>
>
>hmm, but everything returns only positive vales of depth
>this isn't all

Sure it is.  "All intersections" means "all intersections of the object with
a ray."  Since a ray goes only one direction from a point, all of the
intersections with that ray will be in a positive direction.

-- 
Ron Parker   http://www2.fwi.com/~parkerr/traces.html
My opinions.  Mine.  Not anyone else's.

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Ron Parker wrote in message ...
>On Mon, 11 Dec 2000 13:57:57 +0100, Wlodzimierz ABX Skiba wrote:
>>Ron Parker wrote in message ...
>>> >All_XXX_Intersections()
>>> >
>>> >why this not return ALL if there is ALL in name ?
>>>
>>> It should return all, but meshes and some other objects are exceptions to
>>> the rule, usually for speed considerations.  Anything you can use in CSG
>>> should definitely return all.
>>
>>
>>hmm, but everything returns only positive vales of depth
>>this isn't all
>
> Sure it is.  "All intersections" means "all intersections of the object with
> a ray."

unfotunatly I didn't found such comment in code

> Since a ray goes only one direction from a point, all of the
> intersections with that ray will be in a positive direction.


sure, I understand idea
but unfotunatly when I sit to code I consider ray as line
as I said this is annoying only for beginner :-(

ABX

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In article <3a34d6c9@news.povray.org> , "Wlodzimierz ABX Skiba" 
<abx### [at] abxartpl> wrote:

>> Sure it is.  "All intersections" means "all intersections of the object with
>> a ray."
>
> unfotunatly I didn't found such comment in code

Doesn't the function take a "Ray" as argument?

This might have to do with that fact that POV-Ray is something called a
"ray-tracer", not a "line-tracer" ;-)


   Thorsten

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Thorsten Froehlich wrote in message <3a34f263$1@news.povray.org>...
>In article <3a34d6c9@news.povray.org> , "Wlodzimierz ABX Skiba"
><abx### [at] abxartpl> wrote:
>>> Sure it is.  "All intersections" means "all intersections of the object with
>>> a ray."
>>
>> unfotunatly I didn't found such comment in code
>
> Doesn't the function take a "Ray" as argument?

sure, trivial, simple ?
parametric equation of line is exactly ray equation
vector structure is used for both: vectors and points

I thought at first that for csg operation
this always return all intersections and only filter it later

> This might have to do with that fact that POV-Ray is something called a
> "ray-tracer", not a "line-tracer" ;-)


oh, common! I just forgot ;-)

ABX

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