[Radiance-general] aspect ratio problem

[Jack de Valpine]

Hi,

Thinking about the geometry, I believe that you actually need the following:

    tan(vv/2) / tan(hh/2) = (height/2) / (width /2)

    ==

    tan(vv/2) / tan(hh/2)  =  height  / width

solving for vv:

    vv = 2* atan( height / width  * tan(hh/2))

given:

    hh = 84
    height  = 576
    width = 1024

    vv = 53.7224 degrees

-Jack

Siegbert Debatin wrote:
>> I have a real problem in understanding goniometry :(
>>
>> Do you know how to solve your equotation when the horizontal view 
>> angle is known?
>> In other words, how do I get the value of vv when:
>>
>> tan(vv) / tan ( 84 degrees ) = 576/1024
>
> In 2 steps:
> tan(vv) = tan( 84 degrees ) * 576 / 1024
> vv = atan( tan( 84 degrees ) * 576 / 1024 )
> which gives vv = 79.4 degrees.
>
> Siegbert
> --Dr.-Ing. Siegbert Debatin
> Development
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# Jack de Valpine
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#
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