hello folks.
i have files (fish eye rendered images) of my project. im doing glare
analysis using Evalglare program and following the tutorial by Shelby Doyle
and Christoph Reinhart in a step by step manner.
the mistake what i have done is: i have rendered all the images in
hemispherical view (vth) and the evalglare program takes only vta i.e
angular.
it took long to render those images around 150 files. this means i have to
render everyhting again by changing the the view type to angular and render.
my doubt is is there any other method where i can get the glare analysis
done with the hemispehrical view itself which is also 180degree fish eye.
this will save my time.
thanks alot.
will be really helpful if i get the solution
thanks
regards
dhaRam
Hi Dharam,
I guess you would be able to implement a reprojection for the images, either using Radiance's tools or any other software. You could e.g. start with vwrays -vta (...), which would give you for each pixel of your required -vta-projection the corresponding vectors. Using rcalc, you could calculate backwards at which pixel-coordinates in a vth-projected image of given dimensions the pixel-value for this direction is found. The problem is that there will be some interpolation needed in the process. I am not sure whether this will be faster then re-rendering the images. Did you keep all the files for the renderings, especially the ambient data? Depending on how you did the renderings, doing a second run with only changed view-parameters, but existing ambient cache data could be very quick.
Cheers, Lars.
I agree with Lars. I would rather re-render the images.
Too bad that I missed the Radiance workshop. I was in Germany celebrating my Grandpa's 95th birthday.
Christoph
···
-----Original Message-----
From: Lars O. Grobe [mailto:[email protected]]
Sent: Monday, August 29, 2011 10:18 AM
To: Radiance general discussion
Subject: Re: [Radiance-general] glare analysis
Hi Dharam,
I guess you would be able to implement a reprojection for the images, either using Radiance's tools or any other software. You could e.g.
start with vwrays -vta (...), which would give you for each pixel of your required -vta-projection the corresponding vectors. Using rcalc, you could calculate backwards at which pixel-coordinates in a vth-projected image of given dimensions the pixel-value for this direction is found. The problem is that there will be some interpolation needed in the process. I am not sure whether this will be faster then re-rendering the images. Did you keep all the files for the renderings, especially the ambient data? Depending on how you did the renderings, doing a second run with only changed view-parameters, but existing ambient cache data could be very quick.
Cheers, Lars.
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Actually, you should be able to reproject the pixels using pinterp. Try the following:
pinterp -vf rend_vth.hdr -x orig_xres -y orig_yres -vta rend_vth.hdr 1.0 > rend_vta.hdr
Cheers,
-Greg
···
From: dharam <[email protected]>
Date: August 29, 2011 6:36:47 AM PDT
hello folks.
i have files (fish eye rendered images) of my project. im doing glare analysis using Evalglare program and following the tutorial by Shelby Doyle and Christoph Reinhart in a step by step manner.
the mistake what i have done is: i have rendered all the images in hemispherical view (vth) and the evalglare program takes only vta i.e angular.
it took long to render those images around 150 files. this means i have to render everyhting again by changing the the view type to angular and render.
my doubt is is there any other method where i can get the glare analysis done with the hemispehrical view itself which is also 180degree fish eye. this will save my time.
thanks alot.
will be really helpful if i get the solution
thanks
regards
dhaRam
Actually, you should be able to reproject the pixels using pinterp. Try the following:
Greg, I had NO clue that pinterp can be used as a tool for reprojection, even though I just found it is all written in the manpage. For me, it was always an animation tool to interpolate in between frames.
Great!!!
Lars.
Hi Lars,
It's a good day when I can teach _you_ something new about Radiance!
Cheers,
-Greg
···
From: "Lars O. Grobe" <[email protected]>
Date: August 29, 2011 9:02:04 AM PDT
Actually, you should be able to reproject the pixels using pinterp. Try the following:
Greg, I had NO clue that pinterp can be used as a tool for reprojection, even though I just found it is all written in the manpage. For me, it was always an animation tool to interpolate in between frames.
Great!!!
Lars.
thank you very much sir. il surely try and post u the result...
thanks alot..
regards
dhaRam
It's a good day when I can teach _you_ something new about Radiance!
Hi Greg! Great news for you: there is plenty of potential left then for having good days 
Lars.
good evening sir.
actually im using "*.pic*" files .. i guess instead of .hdr i can replace it
with .pic .....am i rite sir? or will it make a difference
and i did this and an error message is displayed "read error"
can u guide me sir.
[i went through the userman and there is a command for changing angular to
hemispherical fish eye and i need the other way round. 
]
'pinterp -vf fish.hdr -vth -ff fish.hdr 1 > hemi.hdr'
thank you sir
regards
dhaRam
Hi dhaRam!
In old times, we used .pic (picture) as a file extension in Radiance. This however caused some confusion, as there are a lot of differen formats using the same extension. So some years ago, folks started to name Radiance "image" data files .hdr (high dynamic range). This is also officially registred as a mime-type now, and in general is preferred. However Radiance does not really care about the name of your files.
So if your vht-projected image is in file fish.pic and you want to keep the old naming, just adopt the command line accordingly.
'pinterp -vf fish.hdr -vth -ff fish.hdr 1 > hemi.hdr'
will thus become
pinterp -vf fish.pic -vth -ff fish.pic 1 > hemi.pic
BUT: If you have a closer look at Greg's mail, you will find that you do something quite different, and I do not really know why. Why do you use other parameters then Greg proposed?
Cheers, Lars.
hello sir.
that was exactly i was confused about. in Greg's mail he mentioned about x
res and y res ..... so i was confused with that and hence again mailed back.
the method given is angular to hemispherical ......and i need the other way
round.......so if i use the same command by just replacing fish (angular)
with hemispherical wil the commnad be same .... ( im supposing no) ... pls
let me kno about it sir...
thank you..
p.s- - as im exploring radiance more and more its getting interesting....
and i want to thank you for it sir....
thanks..
regards
dhaRam
Hi dhaRam,
Your initial e-mail said you had -vth images and needed -vta, so that's the way I wrote the pinterp command, giving the original view first, then updating it with '-vta'. The -x and -y resolution options are needed because pinterp otherwise defaults to 512x512, and you may not want that. The default filling option ('-fa') should work fine in your case, which is why I didn't specify anything for -f. Using '-ff' may result in some black pixels, which you don't want to send to evalglare as it would skew your results.
A little experimentation should resolve any outstanding issues.
Best,
-Greg
···
From: dharam <[email protected]>
Date: August 30, 2011 8:01:53 AM PDT
hello sir.
that was exactly i was confused about. in Greg's mail he mentioned about x res and y res ..... so i was confused with that and hence again mailed back.
the method given is angular to hemispherical ......and i need the other way round.......so if i use the same command by just replacing fish (angular) with hemispherical wil the commnad be same .... ( im supposing no) ... pls let me kno about it sir...
thank you..
p.s- - as im exploring radiance more and more its getting interesting.... and i want to thank you for it sir....
thanks..
regards
dhaRam
]