Turbidity

General questions about Indigo, the scene format, rendering etc...
Post Reply
10 posts • Page 1 of 1
User avatar
Pibuz
1st Place 100
Posts: 2646
Joined: Tue Dec 11, 2007 7:58 am
Location: Padua, Italy
3D Software: SketchUp

Turbidity

Post by Pibuz » Fri Nov 13, 2009 11:33 am

Sorry guys, I was just testing again the turbidity parameter for I'm writing a small tutorial about lighting for the Indigo italian forum. I just experienced something I was not expecting, indeed.
I was sure that low turbidity parameters would actually lead to more blue images, and high values to more yellow-orange images.
So I did two tests and these are the results: the value of 2 gives more blueish tones than 1.5, which confuses me a little. :roll:

I have to say that the render with turbidity=2 was done with the 2.2.6 version, while the render with turbidity=1.5 was done with the 2.2.7 version.

So I ask you all: is that all correct? Is this some kind of bug? I was wrong assuming that 1.5 would have led to a more blue-tinted image?

Thank you for your anwers!
Attachments
turb1.5.png
Done with Indigo 2.2.7
turb1.5.png (475.62 KiB) Viewed 2438 times
turb2.png
Done with Indigo 2.2.6
turb2.png (309.78 KiB) Viewed 2437 times

User avatar
Zom-B
1st Place 100
Posts: 4684
Joined: Tue Jul 04, 2006 4:18 pm
Location: ´'`\_(ò_Ó)_/´'`
Contact:

Re: Turbidity

Post by Zom-B » Fri Nov 13, 2009 1:30 pm

Turbidity was always quite some strange parameter... afaik 1.8 was the lowest giving correct results.
Anyway, I would love to have it working as supposed...
polygonmanufaktur.de

User avatar
Pibuz
1st Place 100
Posts: 2646
Joined: Tue Dec 11, 2007 7:58 am
Location: Padua, Italy
3D Software: SketchUp

Re: Turbidity

Post by Pibuz » Fri Nov 13, 2009 8:08 pm

In SkIndigo we have a scrollbar, so I guess 1.5 is the real lowest possible parameter, and 7.5 is the highest.

User avatar
Pibuz
1st Place 100
Posts: 2646
Joined: Tue Dec 11, 2007 7:58 am
Location: Padua, Italy
3D Software: SketchUp

Re: Turbidity

Post by Pibuz » Sat Nov 14, 2009 5:36 am

Here are some other comparisons. I find that the turbidity parameter has been somehow heavily corrupted by other lines of the code. The maximum turbidity leads to a slightly coloured image, while in the past would have meant a really orange overall tone. I guess this is a bug.
Attachments
turbidity test.jpg
turbidity test.jpg (416.05 KiB) Viewed 2292 times

User avatar
CTZn
Posts: 7240
Joined: Thu Nov 16, 2006 4:34 pm
Location: Paris, France

Re: Turbidity

Post by CTZn » Sat Nov 14, 2009 9:22 am

I do not think that turbidity should be set below 2 (is that parameter an exponent ?), or you may be stressing the model a bit.
obsolete asset

User avatar
Pibuz
1st Place 100
Posts: 2646
Joined: Tue Dec 11, 2007 7:58 am
Location: Padua, Italy
3D Software: SketchUp

Re: Turbidity

Post by Pibuz » Sat Nov 14, 2009 10:10 pm

Thank you CTZn for following me.

I'm now asking for help here: is anyone still using a previous version of Indigo? Better: SkIndigo?

I'd ask if it could be possible to do four tests with the turbidity values I've set for my latest test, and post the result, a detailed model is not needed: a cuve with a plane in the background will do the job. I think the overall atmosphere will come out quite different, using version 2.2.6 or previous.

User avatar
mr_jo
Posts: 29
Joined: Wed Jan 23, 2008 9:36 am
Location: Caserta (Italy)

Re: Turbidity

Post by mr_jo » Sun Nov 15, 2009 7:49 am

Pibuz wrote:... is anyone still using a previous version of Indigo? Better: SkIndigo?
I'd ask if it could be possible to do four tests with the turbidity values I've set for my latest test, and post the result,
Hi Pibuz and all, I'm using Indigo 2.2.1 and SkIndigo 2.2.3.
I've done four test with your turbidity values, White Point set to E
here's the result
Attachments
turbidity test_mj.jpg
Indigo 2.2.1 and SkIndigo 2.2.3
turbidity test_mj.jpg (248.37 KiB) Viewed 2101 times

User avatar
OnoSendai
Developer
Posts: 6196
Joined: Sat May 20, 2006 6:16 pm
Location: Wellington, NZ
Contact:

Re: Turbidity

Post by OnoSendai » Sun Nov 15, 2009 11:01 am

IIRC, turbidity should always be set in the range 2 to 6, due to limitations of the original model.

User avatar
Pibuz
1st Place 100
Posts: 2646
Joined: Tue Dec 11, 2007 7:58 am
Location: Padua, Italy
3D Software: SketchUp

Re: Turbidity

Post by Pibuz » Sun Nov 15, 2009 9:51 pm

OnoSendai wrote:turbidity should always be set in the range 2 to 6, due to limitations of the original model.
That's something Whaat has to fix in SkIndigo then :wink:
OR you have to increase the range Ono :lol: BTW this is a silly thing, I know..

mr_jo:
Thank you very much for your tests. really informative.
Now, for a proper comparison I'd say we have to test again with "accepted" values.
can you do some tests with Turbidity equal to 2 - 4.5 - 6?
I'll do the same with 2.2.7 version. Thank you a lot!

User avatar
mr_jo
Posts: 29
Joined: Wed Jan 23, 2008 9:36 am
Location: Caserta (Italy)

Re: Turbidity

Post by mr_jo » Mon Nov 16, 2009 8:44 am

Hi Pibuz, here's the result
P.S. I've changed a little bit the gray from the previous test
Attachments
turbidity test_bis_mj.jpg
Indigo 2.2.1 and SkIndigo 2.2.3
turbidity test_bis_mj.jpg (289.5 KiB) Viewed 1865 times

Post Reply
10 posts • Page 1 of 1

Who is online

Users browsing this forum: No registered users and 2 guests