ripples in my pools...

Dear list,

I've managed to create unwanted diffuse "ripples" within diffuse pools of light. I'm working with -aa 0 renderings, and having a tough time smoothing things out.

In this example,<https://www.dropbox.com/s/fr23tpnv5uqlhxg/clear_section.jpg?dl=0> the diffuse bit of sky component directly below the skylight has subtle ripples of darkness in the pool of light, and also in the bright ceiling above the patch of direct sun...

With a trans material in the skylight<https://www.dropbox.com/s/ptco2powrlhy48x/diffuse_section.jpg?dl=0>, the pattern is even more noticeable, and you can see it mapped onto the walls of the scene as well...

Settings for these runs (which are oversampled x12):
-dp 4096 -ms .14 -ds .1 -dj .9 -dt .05 -dr 3 -ss 16 -st .01 -ab 3 -av 0 0 0 -ar 0 -ad 64 -as 0 -aa 0 -ps 1 -pt .04 -lr 12 -lw 1e-5

Things I've tried with no luck:
- big and small -ar values; 300, 800, 3000 (I recall an old tip from Mark Stock to crank -ar with -aa 0 to get rid of halos?)
- various -ad settings (16, 32 64, 200) while keeping -as 0
-turned on -as with -ad 64 and -as 32
- tried a negative value for -lr
- tried making -lw super small; 1e-10

I'm using the rad program to turn on penumbras - maybe there's something in the -dx, -sx, or -px settings I'm unaware of?

Many thanks for any ideas...

MM

Hi Michael,

Shouldn’t really happen, nonetheless perhaps it is possible that there’s some weird alias like effect happening with this geometry and the very small ad.

Do your renderings have to be aa 0, and have you tried larger ad values?

Cheers
John

Vote for climate-based daylight modelling:
http://www.lboro.ac.uk/enterprise/enterprise-awards/impact/daylight-modelling/

John Mardaljevic PhD FSLL
Professor of Building Daylight Modelling
School of Civil & Building Engineering
Loughborough University
Loughborough
Leicestershire
LE11 3TU, UK

Tel: +44 1509 222630 (Direct)
Tel: +44 1509 228529 (Pam Allen, secretary)

[email protected]<mailto:[email protected]>

http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn/<http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn>

Personal daylighting website:
http://climate-based-daylighting.com<http://climate-based-daylighting.com/>

Are you using pcond on the image? I had a similar looking issue caused by
pcond :

Andy

···

On Fri, May 5, 2017 at 4:12 AM, John Mardaljevic <[email protected]> wrote:

Hi Michael,

Shouldn’t really happen, nonetheless perhaps it is possible that there’s
some weird alias like effect happening with this geometry and the very
small ad.

Do your renderings have to be aa 0, and have you tried larger ad values?

Cheers
John

Vote for climate-based daylight modelling:
http://www.lboro.ac.uk/enterprise/enterprise-awards/
impact/daylight-modelling/

John Mardaljevic PhD FSLL
Professor of Building Daylight Modelling
School of Civil & Building Engineering
Loughborough University
Loughborough
Leicestershire
LE11 3TU, UK

Tel: +44 1509 222630 <+44%201509%20222630> (Direct)
Tel: +44 1509 228529 <+44%201509%20228529> (Pam Allen, secretary)

[email protected]

http://www.lboro.ac.uk/departments/civil-building/staff/mardaljevicjohn/

Personal daylighting website:
http://climate-based-daylighting.com

_______________________________________________
Radiance-general mailing list
[email protected]
https://www.radiance-online.org/mailman/listinfo/radiance-general

Hi Michael,

Adding back original message, which somehow got lost in my spam folder...

Which version of Radiance are you using? (I.e., what does "rpict -version" say?) I found a couple of minor sampling issues in the interreflection code, though I'm not sure if they could cause this effect. The last fix was a couple of weeks ago, so pretty recent by Radiance standards.

-Greg

P.S. If you send me your scene in a private e-mail, I'll have a closer look when I get a chance.

···

From: Andy McNeil <[email protected]>
Date: May 5, 2017 8:21:36 AM PDT

Are you using pcond on the image? I had a similar looking issue caused by pcond : https://unmethours.com/question/10506/how-do-i-avoid-banding-when-im-tone-mapping-radiance-images-using-pcond-and-phisto/

Andy

On Fri, May 5, 2017 at 4:12 AM, John Mardaljevic <[email protected]> wrote:
Hi Michael,

Shouldn’t really happen, nonetheless perhaps it is possible that there’s some weird alias like effect happening with this geometry and the very small ad.

Do your renderings have to be aa 0, and have you tried larger ad values?

Cheers
John

Vote for climate-based daylight modelling:
http://www.lboro.ac.uk/enterprise/enterprise-awards/impact/daylight-modelling/

John Mardaljevic PhD FSLL

----------- Original Message -----------

From: Michael Martinez <[email protected]>
Date: May 4, 2017 at 12:27:18 PM PDT
To: Radiance general discussion <[email protected]>
Subject: [!!SP: THIS MESSAGE IS SPAM] [Radiance-general] ripples in my pools...

Dear list,

I’ve managed to create unwanted diffuse “ripples” within diffuse pools of light. I’m working with –aa 0 renderings, and having a tough time smoothing things out.

In this example <https://www.dropbox.com/s/fr23tpnv5uqlhxg/clear_section.jpg?dl=0>, the diffuse bit of sky component directly below the skylight has subtle ripples of darkness in the pool of light, and also in the bright ceiling above the patch of direct sun…

With a trans material in the skylight <https://www.dropbox.com/s/ptco2powrlhy48x/diffuse_section.jpg?dl=0>, the pattern is even more noticeable, and you can see it mapped onto the walls of the scene as well…

Settings for these runs (which are oversampled x12):
-dp 4096 –ms .14 –ds .1 –dj .9 –dt .05 –dr 3 –ss 16 –st .01 –ab 3 –av 0 0 0 –ar 0 –ad 64 –as 0 –aa 0 –ps 1 –pt .04 –lr 12 –lw 1e-5

Things I’ve tried with no luck:
- big and small –ar values; 300, 800, 3000 (I recall an old tip from Mark Stock to crank -ar with –aa 0 to get rid of halos?)
- various –ad settings (16, 32 64, 200) while keeping –as 0
-turned on –as with -ad 64 and –as 32
- tried a negative value for –lr
- tried making –lw super small; 1e-10

I’m using the rad program to turn on penumbras – maybe there’s something in the –dx, -sx, or –px settings I’m unaware of?

Many thanks for any ideas…

MM

I've gotten this error on multiple projects, It's visible in rvu, rpict
results and images made with rtrace. It is most apparent on -ab 1 so it
comes from either the light through the skylight direct from skyglow (with
a clear material) or the first ray through the trans material from a direct
source. Small openings have more pronounced patterning compared with
larger openings (large opening at top small opening at bottom:
https://goo.gl/photos/stsFoix8s4cE3wk46). It looks like a diffraction
pattern and kind of behaves like one (smaller opening, more prominent),
does something in the ray sampling explain why the apertures act like
diffraction slits? would it go away with a really high -ad? is it also
there with ambient caching, but the interpolation smooths it out?

Stephen Wasilewski
*LOISOS *+* UBBELOHDE*
- - - - - - - - - - - - - - - - - - - - - - - - - - -
1917 Clement Avenue Building 10A
Alameda, CA 94501 USA
- - - - - - - - - - - - - - - - - - - - - - - - - - -
510 521 3800 VOICE
510 521 3820 FAX
- - - - - - - - - - - - - - - - - - - - - - - - - - -
www.coolshadow.com

···

On Fri, May 5, 2017 at 8:41 AM, Greg Ward <[email protected]> wrote:

Hi Michael,

Adding back original message, which somehow got lost in my spam folder...

Which version of Radiance are you using? (I.e., what does "rpict
-version" say?) I found a couple of minor sampling issues in the
interreflection code, though I'm not sure if they could cause this effect.
The last fix was a couple of weeks ago, so pretty recent by Radiance
standards.

-Greg

P.S. If you send me your scene in a private e-mail, I'll have a closer
look when I get a chance.

*From: *Andy McNeil <[email protected]>

*Date: *May 5, 2017 8:21:36 AM PDT

Are you using pcond on the image? I had a similar looking issue caused by
pcond : https://unmethours.com/question/10506/how-do-i-avoid-
banding-when-im-tone-mapping-radiance-images-using-pcond-and-phisto/

Andy

On Fri, May 5, 2017 at 4:12 AM, John Mardaljevic < > [email protected]> wrote:

Hi Michael,

Shouldn’t really happen, nonetheless perhaps it is possible that there’s
some weird alias like effect happening with this geometry and the very
small ad.

Do your renderings have to be aa 0, and have you tried larger ad values?

Cheers
John

Vote for climate-based daylight modelling:
http://www.lboro.ac.uk/enterprise/enterprise-awards/impact/
daylight-modelling/

John Mardaljevic PhD FSLL

----------- Original Message -----------

*From:* Michael Martinez <[email protected]>
*Date:* May 4, 2017 at 12:27:18 PM PDT
*To:* Radiance general discussion <[email protected]>
*Subject:* *[!!SP: THIS MESSAGE IS SPAM] [Radiance-general] ripples in my
pools...*

Dear list,

I’ve managed to create unwanted diffuse “ripples” within diffuse pools of
light. I’m working with –aa 0 renderings, and having a tough time smoothing
things out.

In this example
<https://www.dropbox.com/s/fr23tpnv5uqlhxg/clear_section.jpg?dl=0> <
https://www.dropbox.com/s/fr23tpnv5uqlhxg/clear_section.jpg?dl=0>,
<https://www.dropbox.com/s/fr23tpnv5uqlhxg/clear_section.jpg?dl=0> the
diffuse bit of sky component directly below the skylight has subtle ripples
of darkness in the pool of light, and also in the bright ceiling above the
patch of direct sun…

With a trans material in the skylight
<https://www.dropbox.com/s/ptco2powrlhy48x/diffuse_section.jpg?dl=0> <
https://www.dropbox.com/s/ptco2powrlhy48x/diffuse_section.jpg?dl=0>, the
pattern is even more noticeable, and you can see it mapped onto the walls
of the scene as well…

Settings for these runs (which are oversampled x12):
-dp 4096 –ms .14 –ds .1 –dj .9 –dt .05 –dr 3 –ss 16 –st .01 –ab 3 –av 0 0
0 –ar 0 –ad 64 –as 0 –aa 0 –ps 1 –pt .04 –lr 12 –lw 1e-5

Things I’ve tried with no luck:
- big and small –ar values; 300, 800, 3000 (I recall an old tip from
Mark Stock to crank -ar with –aa 0 to get rid of halos?)
- various –ad settings (16, 32 64, 200) while keeping –as 0
-turned on –as with -ad 64 and –as 32
- tried a negative value for –lr
- tried making –lw super small; 1e-10

I’m using the rad program to turn on penumbras – maybe there’s something
in the –dx, -sx, or –px settings I’m unaware of?

Many thanks for any ideas…

MM

_______________________________________________
Radiance-general mailing list
[email protected]
https://www.radiance-online.org/mailman/listinfo/radiance-general

This artifact appears to be fixed in the CVS head. It must have been related to sample collision avoidance, which I was doing in a rather ham-fisted way in the first Hessian implementation. (And yes, it affected results with -aa 0 more noticeably.) The newer version of ambcomp.c uses a more subtle and successful rejection sampling method, which doesn't bias the original samples.

I put this fix in back in October, but we've been waiting on some unrelated code changes before building the changes into the latest Windows distro. So, if you're working from that, or you haven't installed the more recent binaries for Linux or Mac, you should do that first.

Cheers,
-Greg

···

From: Stephen Wasilewski <[email protected]>
Date: May 5, 2017 10:02:52 AM PDT

I've gotten this error on multiple projects, It's visible in rvu, rpict results and images made with rtrace. It is most apparent on -ab 1 so it comes from either the light through the skylight direct from skyglow (with a clear material) or the first ray through the trans material from a direct source. Small openings have more pronounced patterning compared with larger openings (large opening at top small opening at bottom: https://goo.gl/photos/stsFoix8s4cE3wk46). It looks like a diffraction pattern and kind of behaves like one (smaller opening, more prominent), does something in the ray sampling explain why the apertures act like diffraction slits? would it go away with a really high -ad? is it also there with ambient caching, but the interpolation smooths it out?

Stephen Wasilewski

On Fri, May 5, 2017 at 8:41 AM, Greg Ward <[email protected]> wrote:
Hi Michael,

Adding back original message, which somehow got lost in my spam folder...

Which version of Radiance are you using? (I.e., what does "rpict -version" say?) I found a couple of minor sampling issues in the interreflection code, though I'm not sure if they could cause this effect. The last fix was a couple of weeks ago, so pretty recent by Radiance standards.

-Greg

P.S. If you send me your scene in a private e-mail, I'll have a closer look when I get a chance.

From: Andy McNeil <[email protected]>
Date: May 5, 2017 8:21:36 AM PDT

Are you using pcond on the image? I had a similar looking issue caused by pcond : https://unmethours.com/question/10506/how-do-i-avoid-banding-when-im-tone-mapping-radiance-images-using-pcond-and-phisto/

Andy

On Fri, May 5, 2017 at 4:12 AM, John Mardaljevic <[email protected]> wrote:
Hi Michael,

Shouldn’t really happen, nonetheless perhaps it is possible that there’s some weird alias like effect happening with this geometry and the very small ad.

Do your renderings have to be aa 0, and have you tried larger ad values?

Cheers
John

Vote for climate-based daylight modelling:
http://www.lboro.ac.uk/enterprise/enterprise-awards/impact/daylight-modelling/

John Mardaljevic PhD FSLL

----------- Original Message -----------

From: Michael Martinez <[email protected]>
Date: May 4, 2017 at 12:27:18 PM PDT
To: Radiance general discussion <[email protected]>
Subject: [!!SP: THIS MESSAGE IS SPAM] [Radiance-general] ripples in my pools...

Dear list,

I’ve managed to create unwanted diffuse “ripples” within diffuse pools of light. I’m working with –aa 0 renderings, and having a tough time smoothing things out.

In this example <https://www.dropbox.com/s/fr23tpnv5uqlhxg/clear_section.jpg?dl=0>, the diffuse bit of sky component directly below the skylight has subtle ripples of darkness in the pool of light, and also in the bright ceiling above the patch of direct sun…

With a trans material in the skylight <https://www.dropbox.com/s/ptco2powrlhy48x/diffuse_section.jpg?dl=0>, the pattern is even more noticeable, and you can see it mapped onto the walls of the scene as well…

Settings for these runs (which are oversampled x12):
-dp 4096 –ms .14 –ds .1 –dj .9 –dt .05 –dr 3 –ss 16 –st .01 –ab 3 –av 0 0 0 –ar 0 –ad 64 –as 0 –aa 0 –ps 1 –pt .04 –lr 12 –lw 1e-5

Things I’ve tried with no luck:
- big and small –ar values; 300, 800, 3000 (I recall an old tip from Mark Stock to crank -ar with –aa 0 to get rid of halos?)
- various –ad settings (16, 32 64, 200) while keeping –as 0
-turned on –as with -ad 64 and –as 32
- tried a negative value for –lr
- tried making –lw super small; 1e-10

I’m using the rad program to turn on penumbras – maybe there’s something in the –dx, -sx, or –px settings I’m unaware of?

Many thanks for any ideas…

MM

Ah! Nothing better than new source code to fix your problem... Just installed the latest HEAD and everything looking great with rpict version 5.1a<https://www.dropbox.com/s/41rx9ii17qwepgi/51a.jpg?dl=0>.

Thanks for the feedback everyone.

I had originally run with version 4.3a (eesh - old...). Tried with 5.0 official release, still no good<https://www.dropbox.com/s/cx83dihv0uucyf0/50.jpg?dl=0>.

Stefan - glad I wasn't the only one...

Andy - yep, using pcond but as Stephen mentioned, it was visible any way you looked at it.

John - I've been using more and more -aa 0 runs for models with more and more detail. This one doesn't require it, but is a set of tests trying to fine tune settings for -aa 0 runs to be accurate enough and fast enough compared to a 'traditional' run.

Thanks again,

Mike Martinez | Integral Group
Associate Principal | Daylighting
d: 510.457.0107<tel:510.457.0107>
p: 510.663.2070 x2007<tel:510.663.2070%20x2007>

···

From: Greg Ward [mailto:[email protected]]
Sent: Friday, May 05, 2017 10:48 AM
To: Radiance general discussion <[email protected]>
Subject: Re: [Radiance-general] ripples in my pools...

This artifact appears to be fixed in the CVS head. It must have been related to sample collision avoidance, which I was doing in a rather ham-fisted way in the first Hessian implementation. (And yes, it affected results with -aa 0 more noticeably.) The newer version of ambcomp.c uses a more subtle and successful rejection sampling method, which doesn't bias the original samples.

I put this fix in back in October, but we've been waiting on some unrelated code changes before building the changes into the latest Windows distro. So, if you're working from that, or you haven't installed the more recent binaries for Linux or Mac, you should do that first.

Cheers,
-Greg

From: Stephen Wasilewski <[email protected]<mailto:[email protected]>>

Date: May 5, 2017 10:02:52 AM PDT

I've gotten this error on multiple projects, It's visible in rvu, rpict results and images made with rtrace. It is most apparent on -ab 1 so it comes from either the light through the skylight direct from skyglow (with a clear material) or the first ray through the trans material from a direct source. Small openings have more pronounced patterning compared with larger openings (large opening at top small opening at bottom: https://goo.gl/photos/stsFoix8s4cE3wk46). It looks like a diffraction pattern and kind of behaves like one (smaller opening, more prominent), does something in the ray sampling explain why the apertures act like diffraction slits? would it go away with a really high -ad? is it also there with ambient caching, but the interpolation smooths it out?

Stephen Wasilewski

On Fri, May 5, 2017 at 8:41 AM, Greg Ward <[email protected]<mailto:[email protected]>> wrote:

Hi Michael,

Adding back original message, which somehow got lost in my spam folder...

Which version of Radiance are you using? (I.e., what does "rpict -version" say?) I found a couple of minor sampling issues in the interreflection code, though I'm not sure if they could cause this effect. The last fix was a couple of weeks ago, so pretty recent by Radiance standards.

-Greg

P.S. If you send me your scene in a private e-mail, I'll have a closer look when I get a chance.

From: Andy McNeil <[email protected]<mailto:[email protected]>>

Date: May 5, 2017 8:21:36 AM PDT

Are you using pcond on the image? I had a similar looking issue caused by pcond : https://unmethours.com/question/10506/how-do-i-avoid-banding-when-im-tone-mapping-radiance-images-using-pcond-and-phisto/

Andy

On Fri, May 5, 2017 at 4:12 AM, John Mardaljevic <[email protected]<mailto:[email protected]>> wrote:
Hi Michael,

Shouldn't really happen, nonetheless perhaps it is possible that there's some weird alias like effect happening with this geometry and the very small ad.

Do your renderings have to be aa 0, and have you tried larger ad values?

Cheers
John

Vote for climate-based daylight modelling:
http://www.lboro.ac.uk/enterprise/enterprise-awards/impact/daylight-modelling/

John Mardaljevic PhD FSLL

----------- Original Message -----------
From: Michael Martinez <[email protected]<mailto:[email protected]>>
Date: May 4, 2017 at 12:27:18 PM PDT
To: Radiance general discussion <[email protected]<mailto:[email protected]>>
Subject: [!!SP: THIS MESSAGE IS SPAM] [Radiance-general] ripples in my pools...
Dear list,

I've managed to create unwanted diffuse "ripples" within diffuse pools of light. I'm working with -aa 0 renderings, and having a tough time smoothing things out.

In this example<https://www.dropbox.com/s/fr23tpnv5uqlhxg/clear_section.jpg?dl=0> <https://www.dropbox.com/s/fr23tpnv5uqlhxg/clear_section.jpg?dl=0>,<https://www.dropbox.com/s/fr23tpnv5uqlhxg/clear_section.jpg?dl=0> the diffuse bit of sky component directly below the skylight has subtle ripples of darkness in the pool of light, and also in the bright ceiling above the patch of direct sun...

With a trans material in the skylight<https://www.dropbox.com/s/ptco2powrlhy48x/diffuse_section.jpg?dl=0> <https://www.dropbox.com/s/ptco2powrlhy48x/diffuse_section.jpg?dl=0>, the pattern is even more noticeable, and you can see it mapped onto the walls of the scene as well...

Settings for these runs (which are oversampled x12):
-dp 4096 -ms .14 -ds .1 -dj .9 -dt .05 -dr 3 -ss 16 -st .01 -ab 3 -av 0 0 0 -ar 0 -ad 64 -as 0 -aa 0 -ps 1 -pt .04 -lr 12 -lw 1e-5

Things I've tried with no luck:
- big and small -ar values; 300, 800, 3000 (I recall an old tip from Mark Stock to crank -ar with -aa 0 to get rid of halos?)
- various -ad settings (16, 32 64, 200) while keeping -as 0
-turned on -as with -ad 64 and -as 32
- tried a negative value for -lr
- tried making -lw super small; 1e-10

I'm using the rad program to turn on penumbras - maybe there's something in the -dx, -sx, or -px settings I'm unaware of?

Many thanks for any ideas...

MM