POV-Ray : Newsgroups : povray.advanced-users : command capability / syntax : Re: command capability / syntax Server Time
28 Apr 2024 17:58:35 EDT (-0400)
  Re: command capability / syntax  
From: clipka
Date: 26 May 2017 14:00:11
Message: <59286d2b$1@news.povray.org>
Am 26.05.2017 um 19:31 schrieb Kenneth:
> dick balaska <dic### [at] buckosoftcom> wrote:
>> Am 2017-05-25 08:00, also sprach Bald Eagle:
>>> I was wondering if:
>>>
>>> vectors can be used in Boolean conditional statements
>>>
>>> #if (Q = <1, 1, 1>)
>>
>> #if (VEq(Q,<1,1,1>)
>>
> 
> That's interesting; didn't know it could be done. But other comments here imply
> that <1,1,1> is actually <1,1,1,0,0>. In which case, #if(VEq...) would still
> return 0 or "false"(?). Unless VEq5D is used; but the vector would still need
> <1,1,1,1,1>, not <1,1,1>, for even VEq5D to return "true."
> 
> Am I understanding this correctly?

No.

<1,1,1> is /not/ <1,1,1,0,0>.

But if you use <1,1,1> in any context where a 5-dimensional vector is
expected, it will automatically be /expanded/ to <1,1,1,0,0>.

VEq(A,B) compares the first three components of A and B. If the vectors
have more components, those are simply ignored.


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