Rendering parameters help and weird colors

Dear List,

So I have been rendering with some interesting features in SketchUp, like
exporting landscapes (hills and mountains) from GoogleEarth.

Here is a link for you to understand what I am talking
about<https://www.dropbox.com/sh/ltv125db6hjp74a/hsnL6S-_JI>

Anyway, I have been rendering some stuff and I have two doubts:

1.- My environment is basically grey, but only the mountain near my
building is brown; but everything has turned to be brown (as can be seen in
Image2)... is that the "color bleeding" (or something like that)? Is that a
good result? or there is a problem with my modeling?

2.- As can be seen in Image (the one that shows the interior of the
building, looking out), there are some weird effects, making my image to
look as it was painted with a brush or something. What is the parameter
that would help me reduce that?

I am not sure why in Dropbox the images look much more darker than in my
PC. They were created using rpict, and then filtered with "pfilt -x /2 -y
/2 image.hdr > image.tiff"

THANKS VERY MUCH

German

Hey German,

For sure it looks like there is some color bleeding, and also the fact that you have modeled the entire mountain — making your model extents fairly large relative to the area of interest (your building interior) is likely causing you some pain here too. It would be helpful to see your material definitions, and also your rendering parameters (particularly the ambient (-a*) ones).

Rob Guglielmetti
National Renewable Energy Laboratory (NREL)
Commercial Buildings Research Group
15013 Denver West Parkway MS:RSF202
Golden, CO 80401
303.275.4319
[email protected]

···

On 4/17/13 10:12 AM, "Germán Molina Larrain" <[email protected]<mailto:[email protected]>> wrote:

Dear List,

So I have been rendering with some interesting features in SketchUp, like exporting landscapes (hills and mountains) from GoogleEarth.

Here is a link for you to understand what I am talking about<https://www.dropbox.com/sh/ltv125db6hjp74a/hsnL6S-_JI>

Anyway, I have been rendering some stuff and I have two doubts:

1.- My environment is basically grey, but only the mountain near my building is brown; but everything has turned to be brown (as can be seen in Image2)... is that the "color bleeding" (or something like that)? Is that a good result? or there is a problem with my modeling?

2.- As can be seen in Image (the one that shows the interior of the building, looking out), there are some weird effects, making my image to look as it was painted with a brush or something. What is the parameter that would help me reduce that?

I am not sure why in Dropbox the images look much more darker than in my PC. They were created using rpict, and then filtered with "pfilt -x /2 -y /2 image.hdr > image.tiff"

THANKS VERY MUCH

German

Hi Robert,

My material definition was the following (I assume it is easy to notice
what is what)

void glass SL_glass
0
0
3 .92 .92 .92

void plastic GroundMat
0
0
5 0.435 0.306 0.216 .00 0.06

void brightfunc floorpat
2 .4*rand(floor(Px/.25)-.25*floor(Py/.25)-.25)+.6 .
0
0

floorpat plastic Floor
0
0
5
    .3 .3 .3 0 0

void plastic SL_default_material #(basically every wall and ceiling)
0
0
5 .7 .7 .7 0 .01

My ambient parameters were (the rest are all defaults):

-ab 8 -ad 2000 -aa 0.05 -ar 256

THANKS VERY MUCH

German

···

2013/4/17 Guglielmetti, Robert <[email protected]>

Hey German,

For sure it looks like there is some color bleeding, and also the fact
that you have modeled the entire mountain — making your model extents
fairly large relative to the area of interest (your building interior) is
likely causing you some pain here too. It would be helpful to see your
material definitions, and also your rendering parameters (particularly the
ambient (-a*) ones).

Rob Guglielmetti
National Renewable Energy Laboratory (NREL)
Commercial Buildings Research Group
15013 Denver West Parkway MS:RSF202
Golden, CO 80401
303.275.4319
[email protected]

On 4/17/13 10:12 AM, "Germán Molina Larrain" <[email protected]<mailto: > [email protected]>> wrote:

Dear List,

So I have been rendering with some interesting features in SketchUp, like
exporting landscapes (hills and mountains) from GoogleEarth.

Here is a link for you to understand what I am talking about<
https://www.dropbox.com/sh/ltv125db6hjp74a/hsnL6S-_JI>

Anyway, I have been rendering some stuff and I have two doubts:

1.- My environment is basically grey, but only the mountain near my
building is brown; but everything has turned to be brown (as can be seen in
Image2)... is that the "color bleeding" (or something like that)? Is that a
good result? or there is a problem with my modeling?

2.- As can be seen in Image (the one that shows the interior of the
building, looking out), there are some weird effects, making my image to
look as it was painted with a brush or something. What is the parameter
that would help me reduce that?

I am not sure why in Dropbox the images look much more darker than in my
PC. They were created using rpict, and then filtered with "pfilt -x /2 -y
/2 image.hdr > image.tiff"

THANKS VERY MUCH

German

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

On the other hand, the reason I modeled the mountain is to actually
consider the shading it provides (that is the area I am working on)... so I
think just eliminate it would not be the solution.

Is color bleeding a problem that "would occur in real life"?? I mean, is a
modeling problem (clearly the mountain is not completely brown), or a weird
effect of the algorithms involved?

THANKS AGAIN!

German

···

2013/4/17 Germán Molina Larrain <[email protected]>

Hi Robert,

My material definition was the following (I assume it is easy to notice
what is what)

void glass SL_glass
0
0
3 .92 .92 .92

void plastic GroundMat
0
0
5 0.435 0.306 0.216 .00 0.06

void brightfunc floorpat
2 .4*rand(floor(Px/.25)-.25*floor(Py/.25)-.25)+.6 .
0
0

floorpat plastic Floor
0
0
5
    .3 .3 .3 0 0

void plastic SL_default_material #(basically every wall and ceiling)
0
0
5 .7 .7 .7 0 .01

My ambient parameters were (the rest are all defaults):

-ab 8 -ad 2000 -aa 0.05 -ar 256

THANKS VERY MUCH

German

2013/4/17 Guglielmetti, Robert <[email protected]>

Hey German,

For sure it looks like there is some color bleeding, and also the fact
that you have modeled the entire mountain — making your model extents
fairly large relative to the area of interest (your building interior) is
likely causing you some pain here too. It would be helpful to see your
material definitions, and also your rendering parameters (particularly the
ambient (-a*) ones).

Rob Guglielmetti
National Renewable Energy Laboratory (NREL)
Commercial Buildings Research Group
15013 Denver West Parkway MS:RSF202
Golden, CO 80401
303.275.4319
[email protected]

On 4/17/13 10:12 AM, "Germán Molina Larrain" <[email protected]<mailto: >> [email protected]>> wrote:

Dear List,

So I have been rendering with some interesting features in SketchUp, like
exporting landscapes (hills and mountains) from GoogleEarth.

Here is a link for you to understand what I am talking about<
https://www.dropbox.com/sh/ltv125db6hjp74a/hsnL6S-_JI>

Anyway, I have been rendering some stuff and I have two doubts:

1.- My environment is basically grey, but only the mountain near my
building is brown; but everything has turned to be brown (as can be seen in
Image2)... is that the "color bleeding" (or something like that)? Is that a
good result? or there is a problem with my modeling?

2.- As can be seen in Image (the one that shows the interior of the
building, looking out), there are some weird effects, making my image to
look as it was painted with a brush or something. What is the parameter
that would help me reduce that?

I am not sure why in Dropbox the images look much more darker than in my
PC. They were created using rpict, and then filtered with "pfilt -x /2 -y
/2 image.hdr > image.tiff"

THANKS VERY MUCH

German

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

It does look like there's quite a bit of color bleeding, and the thin stripe of sunlight on the floor makes for difficult sampling as well. You would be much better off treating your window as an illum in this case using mkillum. You can follow the tutorial example at the end of chapter 1 if you're not sure how to do this:

  http://radsite.lbl.gov/radiance/book/ch1/ch1.pdf

Cheers,
-Greg

···

From: Germán Molina Larrain <[email protected]>
Date: April 17, 2013 9:12:02 AM PDT

Dear List,

So I have been rendering with some interesting features in SketchUp, like exporting landscapes (hills and mountains) from GoogleEarth.

Here is a link for you to understand what I am talking about

Anyway, I have been rendering some stuff and I have two doubts:

1.- My environment is basically grey, but only the mountain near my building is brown; but everything has turned to be brown (as can be seen in Image2)... is that the "color bleeding" (or something like that)? Is that a good result? or there is a problem with my modeling?

2.- As can be seen in Image (the one that shows the interior of the building, looking out), there are some weird effects, making my image to look as it was painted with a brush or something. What is the parameter that would help me reduce that?

I am not sure why in Dropbox the images look much more darker than in my PC. They were created using rpict, and then filtered with "pfilt -x /2 -y /2 image.hdr > image.tiff"

THANKS VERY MUCH

German

Hi German,

I understand, but the problem with modeling far-reaching terrain is that the spacing between your ambient sampling points blows up quite a bit. What I generally recommend is that you substitute the actual mountain with proxy geometry closer to the building (say, within 100' of the building perimeter) that represents the shading effect of the distant ground. In other words, project the mountain onto flat polygons closer to the scene-

...and Greg just chimed in with a better answer. =)

···

From: Germán Molina Larrain [mailto:[email protected]]
Sent: Wednesday, April 17, 2013 10:35 AM
To: Radiance general discussion
Subject: Re: [Radiance-general] Rendering parameters help and weird colors

On the other hand, the reason I modeled the mountain is to actually consider the shading it provides (that is the area I am working on)... so I think just eliminate it would not be the solution.

Is color bleeding a problem that "would occur in real life"?? I mean, is a modeling problem (clearly the mountain is not completely brown), or a weird effect of the algorithms involved?

THANKS AGAIN!

German

2013/4/17 Germán Molina Larrain <[email protected]<mailto:[email protected]>>
Hi Robert,

My material definition was the following (I assume it is easy to notice what is what)

void glass SL_glass
0
0
3 .92 .92 .92

void plastic GroundMat
0
0
5 0.435 0.306 0.216 .00 0.06

void brightfunc floorpat
2 .4*rand(floor(Px/.25)-.25*floor(Py/.25)-.25)+.6 .
0
0

floorpat plastic Floor
0
0
5
    .3 .3 .3 0 0

void plastic SL_default_material #(basically every wall and ceiling)
0
0
5 .7 .7 .7 0 .01

My ambient parameters were (the rest are all defaults):

-ab 8 -ad 2000 -aa 0.05 -ar 256

THANKS VERY MUCH

German

2013/4/17 Guglielmetti, Robert <[email protected]<mailto:[email protected]>>

Hey German,

For sure it looks like there is some color bleeding, and also the fact that you have modeled the entire mountain - making your model extents fairly large relative to the area of interest (your building interior) is likely causing you some pain here too. It would be helpful to see your material definitions, and also your rendering parameters (particularly the ambient (-a*) ones).

Rob Guglielmetti
National Renewable Energy Laboratory (NREL)
Commercial Buildings Research Group
15013 Denver West Parkway MS:RSF202
Golden, CO 80401
303.275.4319<tel:303.275.4319>
[email protected]<mailto:[email protected]>

On 4/17/13 10:12 AM, "Germán Molina Larrain" <[email protected]<mailto:[email protected]><mailto:[email protected]<mailto:[email protected]>>> wrote:

Dear List,

So I have been rendering with some interesting features in SketchUp, like exporting landscapes (hills and mountains) from GoogleEarth.
Here is a link for you to understand what I am talking about<https://www.dropbox.com/sh/ltv125db6hjp74a/hsnL6S-_JI>

Anyway, I have been rendering some stuff and I have two doubts:

1.- My environment is basically grey, but only the mountain near my building is brown; but everything has turned to be brown (as can be seen in Image2)... is that the "color bleeding" (or something like that)? Is that a good result? or there is a problem with my modeling?

2.- As can be seen in Image (the one that shows the interior of the building, looking out), there are some weird effects, making my image to look as it was painted with a brush or something. What is the parameter that would help me reduce that?

I am not sure why in Dropbox the images look much more darker than in my PC. They were created using rpict, and then filtered with "pfilt -x /2 -y /2 image.hdr > image.tiff"

THANKS VERY MUCH

German
_______________________________________________
Radiance-general mailing list
[email protected]<mailto:[email protected]>
http://www.radiance-online.org/mailman/listinfo/radiance-general

Color bleeding certainly happens in real life, but most mountains are not this orange on average. You have modeled an unusual condition, and might be better moving it to a more neutral color. Also, many cameras perform automatic white balance, which Radiance does not do for you.

-Greg

···

From: Germán Molina Larrain <[email protected]>
Date: April 17, 2013 9:35:28 AM PDT

On the other hand, the reason I modeled the mountain is to actually consider the shading it provides (that is the area I am working on)... so I think just eliminate it would not be the solution.

Is color bleeding a problem that "would occur in real life"?? I mean, is a modeling problem (clearly the mountain is not completely brown), or a weird effect of the algorithms involved?

THANKS AGAIN!

German

2013/4/17 Germán Molina Larrain <[email protected]>
Hi Robert,

My material definition was the following (I assume it is easy to notice what is what)

void glass SL_glass
0
0
3 .92 .92 .92

void plastic GroundMat
0
0
5 0.435 0.306 0.216 .00 0.06

void brightfunc floorpat
2 .4*rand(floor(Px/.25)-.25*floor(Py/.25)-.25)+.6 .
0
0

floorpat plastic Floor
0
0
5
    .3 .3 .3 0 0

void plastic SL_default_material #(basically every wall and ceiling)
0
0
5 .7 .7 .7 0 .01

My ambient parameters were (the rest are all defaults):

-ab 8 -ad 2000 -aa 0.05 -ar 256

THANKS VERY MUCH

German

2013/4/17 Guglielmetti, Robert <[email protected]>

Hey German,

For sure it looks like there is some color bleeding, and also the fact that you have modeled the entire mountain — making your model extents fairly large relative to the area of interest (your building interior) is likely causing you some pain here too. It would be helpful to see your material definitions, and also your rendering parameters (particularly the ambient (-a*) ones).

Rob Guglielmetti
National Renewable Energy Laboratory (NREL)
Commercial Buildings Research Group
15013 Denver West Parkway MS:RSF202
Golden, CO 80401
303.275.4319
[email protected]

On 4/17/13 10:12 AM, "Germán Molina Larrain" <[email protected]<mailto:[email protected]>> wrote:

Dear List,

So I have been rendering with some interesting features in SketchUp, like exporting landscapes (hills and mountains) from GoogleEarth.

Here is a link for you to understand what I am talking about<https://www.dropbox.com/sh/ltv125db6hjp74a/hsnL6S-_JI>

Anyway, I have been rendering some stuff and I have two doubts:

1.- My environment is basically grey, but only the mountain near my building is brown; but everything has turned to be brown (as can be seen in Image2)... is that the "color bleeding" (or something like that)? Is that a good result? or there is a problem with my modeling?

2.- As can be seen in Image (the one that shows the interior of the building, looking out), there are some weird effects, making my image to look as it was painted with a brush or something. What is the parameter that would help me reduce that?

I am not sure why in Dropbox the images look much more darker than in my PC. They were created using rpict, and then filtered with "pfilt -x /2 -y /2 image.hdr > image.tiff"

THANKS VERY MUCH

German

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

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

Because the size of your exterior site geometry is so large compared to your room, you could increase -ar. There's a formula to calculate a good value, which I think is part of what the rad command does if the scene dimensions are set smaller than your whole octree. If your rendering doesn't take too long you could just try increasing it arbitrarily, maybe jump up to 1000 to look for any benefit. You could also try setting -as around 500 instead of the default 128.

Those are the quick and easy things to try, but the recommendations from Rob and Greg might be even better or faster.

My ambient parameters were (the rest are all defaults):

-ab 8 -ad 2000 -aa 0.05 -ar 256

···

From: Germán Molina Larrain [mailto:[email protected]]

____________________________________________________________
Electronic mail messages entering and leaving Arup business
systems are scanned for acceptability of content and viruses

Well, thanks guys! I will try making the -ar bigger, and illum. Is just, I
think that, on the Rendering with Radiance Book, John Mardaljevic mentions
that for daylighting it is not recommended to use Illums.

Anyway... I will use more neutral colors, illums and a higher ambient
resolution as a learning exercise.

*Would this same model cause problems when using the Three-phase method?*

THANKS VERY MUCH

German

German

···

2013/4/17 Christopher Rush <[email protected]>

Because the size of your exterior site geometry is so large compared to
your room, you could increase –ar. There’s a formula to calculate a good
value, which I think is part of what the rad command does if the scene
dimensions are set smaller than your whole octree. If your rendering
doesn’t take too long you could just try increasing it arbitrarily, maybe
jump up to 1000 to look for any benefit. You could also try setting –as
around 500 instead of the default 128.****

** **

Those are the quick and easy things to try, but the recommendations from
Rob and Greg might be even better or faster.****

** **

*From:* Germán Molina Larrain [mailto:[email protected]]

****

My ambient parameters were (the rest are all defaults):****

** **

-ab 8 -ad 2000 -aa 0.05 -ar 256****

** **

** **

____________________________________________________________
Electronic mail messages entering and leaving Arup business
systems are scanned for acceptability of content and viruses

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