[Radiance-general] rpict and rtrace viewpoint differences?

[Paul Lovell]

Thanks Andy,

George


Dr P. George Lovell,

(via iPhone, so apologies for typos and autocorrect shenanigans!)

Lecturer in Psychology
University of Abertay Dundee
Dundee
DD1 1HG

Tel 01382-308581<tel:01382-308581>
Fax 01382-30<tel:01382-308749>

Post-Doctoral Researcher,
School of Psychology, University of St Andrews

RM 2.27 (The Yellow Room).
Phone      (01334) 463056<tel:(01334)%20462085>

On 19 Mar 2014, at 17:31, "Andrew McNeil" <amcneil at lbl.gov<mailto:amcneil at lbl.gov>> wrote:

George,
To generate an image with rtrace you should add -fac and change -osv to -ov.  -fac tells rtrace to expect ascii input and to output in HDR format (4-byte float pixels).
For clipping, planes you can use -va and -vo in the view file.
hope this helps,
Andy


On Wed, Mar 19, 2014 at 7:19 AM, P George Lovell <p.g.lovell at st-andrews.ac.uk<mailto:p.g.lovell at st-andrews.ac.uk>> wrote:
Thanks Chris, I should have noticed that one! (doh!).

I'll listen out for any further advice on the clippin/mapping.

Thanks again.

George



On 19/03/2014 13:57, Chris Coulter wrote:
George,

My guess would be the -vh and -vv included in your rpict command. These will change the x and y mappings of your view.
Are they the same values in your view.vf file? If so, they are redundant and could be misleading in the future. If not, this is why your rpict and rtrace images do not align (vwrays is generating a different set of rays).

Sorry, but I don't have a quick answer/suggestion for your other questions.

Hope this helps.

Chris

-----Original Message-----
From: P George Lovell [mailto:p.g.lovell at st-andrews.ac.uk<mailto:p.g.lovell at st-andrews.ac.uk>]
Sent: Wednesday, March 19, 2014 7:55 AM
To: Radiance general discussion
Subject: [Radiance-general] rpict and rtrace viewpoint differences?

Dear Radiance People.

I'm rendering scenes with both rpict and rtrace and I noticed some discrepancies between them. Despite both using the same view point definitions my images differ between the two renders: (the scene shows a green rectangular panel, a green elipsoid, some sky, green ground).

1) the rpict image (top in the attached file) seems to normalize the sky values so that they aren't too bright.
2) the rtrace image has a subtly different viewpoint.

Three questions:

1) Can you tell me which command arguments determine the way that image values are clipped or remapped?
2) Can I specify the same clipping in rtrace?
3) Why are the views different despite using the same viewpoint?


Here are the commands I'm running, in the sequence that they are executed.

rpict -vf view.vf  -x 2400 -y 2400 -vh 28.07 -vv 28.07 -ps 2 -pt 0.03
-pj 0.95 -dj 0.85 -ds 0.09 -dt 0.03 -dc 0.75 -dr 5 -dp 0 -sj 0.85 -ab 5
-ar 64 -ad 2048 -as 1024 -lr 12 -lw 0.001 wholeScene.rpict

pfilt -x /1 -y /1 -rad 0.60 wholeScene.rpict > wholeScene.pic

vwrays -vf view.vf -x 2400 -y 2400 >surfaces.txt

rtrace -h -osv wholeScene.oct < surfaces.txt > rtrace_surfaces.txt

Best wishes,

George




--
Dr P. George Lovell,

Lecturer in Psychology
University of Abertay Dundee
Dundee
DD1 1HG

Tel 01382-308581
Fax 01382-308749

Researcher/Co-investigator,
School of Psychology, University of St Andrews

RM 2.27 (The Yellow Room).
Phone      (01334) 463056


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