Rendering of a transparent texture usinf colorpict

Hey i am right now trying to visualize a TV screen in radiance. For a
better visual impression i have created an Imaging layer using the
colorpict material.
looking like this:

void colorpict imagin_layer
9 red green blue forestfl.pic . frac(U) frac(V) -s 2
0

imagin_layer trans image
0
7 1 1 1 0 0 1 0

when this is rendered the material is divided into small samples giving an
odd pattern.
here a picture of the rendering:
http://api.ning.com/files/7F975s5rOKhNOb-MzrDw-IgT9VAIHqtJ-jdmmewN42lfsh9FDJX2BIr5Chxy1EG5VXoec5toLZlOaGexMtx8LzXqDF9y3t/Test_lightsource_highres_4096_.15_1024_2.bmp

This is a picture rendering using the standard settings for the high
resolution rendering in diva, except for -ad 4096 -ds 0.15 and -as 1024.
The setup is one imported light source behind the transparent colorpict
material. I have already tried using the ds/dj parameters without luck,
the subdivision seams fixed. Also changing the -n parameter when creating
the .oct file has not worked.

I have tried various combinations of -ad -as -ds -dj and -ps until now.
i hope someone can help.

Niko

Hi Niko,

It is difficult to understand what is going on with your scene based on your description. Can you post the actual scene (with light source), plus with the rpict command you used to generate the image?

Thanks!
-Greg

···

From: giulioandrea antonutto foi <[email protected]>
Subject: Re: [Radiance-general] Rendering of a transparent texture usinf colorpict
Date: March 9, 2015 2:34:09 PM PDT

not sure it is the issue you have but if you use an image to light and this has multiple colour and it is a glow is very difficult to avoid splotches.
you get better results with -aa 0 (at a cost time wise) or by running a Greg script that converts an image in a series of light sources (look for sky imaging lighting)
Hope this helps
>

On 7 Mar 2015, at 11:15, Niko Planke <[email protected]> wrote:

Hey i am right now trying to visualize a TV screen in radiance. For a
better visual impression i have created an Imaging layer using the
colorpict material.
looking like this:

void colorpict imagin_layer
9 red green blue forestfl.pic . frac(U) frac(V) -s 2
0
0

imagin_layer trans image
0
0
7 1 1 1 0 0 1 0

when this is rendered the material is divided into small samples giving an
odd pattern.
here a picture of the rendering:
http://api.ning.com/files/7F975s5rOKhNOb-MzrDw-IgT9VAIHqtJ-jdmmewN42lfsh9FDJX2BIr5Chxy1EG5VXoec5toLZlOaGexMtx8LzXqDF9y3t/Test_lightsource_highres_4096_.15_1024_2.bmp

This is a picture rendering using the standard settings for the high
resolution rendering in diva, except for -ad 4096 -ds 0.15 and -as 1024.
The setup is one imported light source behind the transparent colorpict
material. I have already tried using the ds/dj parameters without luck,
the subdivision seams fixed. Also changing the -n parameter when creating
the .oct file has not worked.

I have tried various combinations of -ad -as -ds -dj and -ps until now.
i hope someone can help.

Niko

Hi Niko,

if you are using the light modifier, it seems you are reaching the maximum
number of 64 source subdivisions (set in source.h). For these cases I would
suggest to follow Guilio's proposal and use the glow modifier instead and
work on the parameters to properly handle rendering time.

Best,
David

···

2015-03-09 23:15 GMT+01:00 Greg Ward <[email protected]>:

Hi Niko,

It is difficult to understand what is going on with your scene based on
your description. Can you post the actual scene (with light source), plus
with the rpict command you used to generate the image?

Thanks!
-Greg

> From: giulioandrea antonutto foi <[email protected]>
> Subject: Re: [Radiance-general] Rendering of a transparent texture usinf
colorpict
> Date: March 9, 2015 2:34:09 PM PDT
>
> not sure it is the issue you have but if you use an image to light and
this has multiple colour and it is a glow is very difficult to avoid
splotches.
> you get better results with -aa 0 (at a cost time wise) or by running a
Greg script that converts an image in a series of light sources (look for
sky imaging lighting)
> Hope this helps
> >
>
> On 7 Mar 2015, at 11:15, Niko Planke <[email protected]> wrote:
>
>> Hey i am right now trying to visualize a TV screen in radiance. For a
>> better visual impression i have created an Imaging layer using the
>> colorpict material.
>> looking like this:
>>
>> void colorpict imagin_layer
>> 9 red green blue forestfl.pic . frac(U) frac(V) -s 2
>> 0
>> 0
>>
>> imagin_layer trans image
>> 0
>> 0
>> 7 1 1 1 0 0 1 0
>>
>> when this is rendered the material is divided into small samples giving
an
>> odd pattern.
>> here a picture of the rendering:
>>
http://api.ning.com/files/7F975s5rOKhNOb-MzrDw-IgT9VAIHqtJ-jdmmewN42lfsh9FDJX2BIr5Chxy1EG5VXoec5toLZlOaGexMtx8LzXqDF9y3t/Test_lightsource_highres_4096_.15_1024_2.bmp
>>
>> This is a picture rendering using the standard settings for the high
>> resolution rendering in diva, except for -ad 4096 -ds 0.15 and -as 1024.
>> The setup is one imported light source behind the transparent colorpict
>> material. I have already tried using the ds/dj parameters without luck,
>> the subdivision seams fixed. Also changing the -n parameter when
creating
>> the .oct file has not worked.
>>
>> I have tried various combinations of -ad -as -ds -dj and -ps until now.
>> i hope someone can help.
>>
>> Niko

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