About angmap.cal

radiance-general
1

Hi
Can anyone explain this statement in the angmap.cal file.
r = if(d,0.159154943*Acos(DDz)/d, 0);

Is the 0.159154943 value related to the focal length and field of view
parameters for Paul Debevec's light map .hdrs, so that if I want to map my own
light maps I must calculate the value of r using my camera parameters (well
simulated in Radiance vv and vh angles) ?

Thanks for any help

Tarik

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Tarik Rahman
PhD student, Institute of Perception, Action and Behaviour
School of Informatics
University of Edinburgh

2

Hi Tarik,

This is an answer to your post about angmap.cal posted some weeks ago.

I am not absolutely sure but I guess 0.159154943 is just to map acos(Dz)/d to values between -0.5 and 0.5.
If you multiply 0.159154943 *PI= 0.5
PI is the greater value that acos(Dz)/d may be.

It does this in order to values of u and v range between 0 and 1.

Despina

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Hi
Can anyone explain this statement in the angmap.cal file.
r = if(d,0.159154943*Acos(DDz)/d, 0);

Is the 0.159154943 value related to the focal length and field of view
parameters for Paul Debevec's light map .hdrs, so that if I want to map my own
light maps I must calculate the value of r using my camera parameters (well
simulated in Radiance vv and vh angles) ?

Thanks for any help

Tarik