Mapping issue with HDR files generated from TIFF

Are both your images square (same number of X and Y pixels)? Radiance has a somewhat peculiar way of handling rectangular images, which could cause scaling discrepancies. See p. 259 of "Rendering with Radiance" for details.

Cheers,
-Greg

···

From: Mostapha Sadeghipour <[email protected]>
Subject: [Radiance-general] Mapping issue with HDR files generated from TIFF
Date: August 22, 2014 8:58:38 PM GMT+02:00

Hello Radiance community,

I'm doing a series of experiments for using a 3rd party 3D software (in this case Rhino) to generate the map and render them with Radiance.

I made a workflow based on Giulio's suggestion (http://www.radiance-online.org/pipermail/radiance-general/2005-July/002851.html), and it works fine when I use Radiance example .hdr files, however when I use a custom pattern ( generated as a tiff image) and convert it to hdr (ra_tiff -r) it doesn't map correctly. Looks like hdr mapping is scaled.

Is there some consideration in generating the tiff file or converting it to hdr that I am missing. I tried to use pfilt and re-size the image to make sure the size is fixed but it didn't help.

Here is a slide that shows the problem:
https://www.dropbox.com/s/eklns2rv5bv6tyj/RhinoVSRadiance.jpg?dl=0

Also the hdr file generated from tiff image in case it can help:
https://www.dropbox.com/s/o293dqh04ack1hb/random_pattern_1.HDR?dl=0

Thanks in advance,
Mostapha

Hi Greg,

That was it. Just rotated the image and it is fixed now! I should have used
a less random pattern to debug. I will update the workflow to mimic
Radiance's approach for coordinates.

Best,
Mostapha

···

On Fri, Aug 22, 2014 at 4:42 PM, Greg Ward <[email protected]> wrote:

Are both your images square (same number of X and Y pixels)? Radiance has
a somewhat peculiar way of handling rectangular images, which could cause
scaling discrepancies. See p. 259 of "Rendering with Radiance" for details.

Cheers,
-Greg

*From: *Mostapha Sadeghipour <[email protected]>

*Subject: *[Radiance-general] Mapping issue with HDR files generated from
TIFF

*Date: *August 22, 2014 8:58:38 PM GMT+02:00

Hello Radiance community,

I'm doing a series of experiments for using a 3rd party 3D software (in
this case Rhino) to generate the map and render them with Radiance.

I made a workflow based on Giulio's suggestion (
http://www.radiance-online.org/pipermail/radiance-general/2005-July/002851.html),
and it works fine when I use Radiance example .hdr files, however when I
use a custom pattern ( generated as a tiff image) and convert it to hdr
(ra_tiff -r) it doesn't map correctly. Looks like hdr mapping is scaled.

Is there some consideration in generating the tiff file or converting it
to hdr that I am missing. I tried to use pfilt and re-size the image to
make sure the size is fixed but it didn't help.

Here is a slide that shows the problem:
https://www.dropbox.com/s/eklns2rv5bv6tyj/RhinoVSRadiance.jpg?dl=0

Also the hdr file generated from tiff image in case it can help:
https://www.dropbox.com/s/o293dqh04ack1hb/random_pattern_1.HDR?dl=0

Thanks in advance,
Mostapha

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