Luminance/Illuminance Analysis

Check out our technology advances and new features.
User avatar
giannis
Thea Developer
Thea Developer
Posts: 7985
Joined: Sun Jul 06, 2008 8:25 pm
Location: Athens, Greece
Has thanked: 11 times
Been thanked: 6 times

Thu May 19, 2011 3:27 pm

I am sure you have seen those false color images that describe the light distribution in a space,
usually to help lighting designers. We are very happy to announce now that this feature has
been added in Thea!

These false color images actually describe the luminance and illuminance distribution. Thea Render
can compute now both of them; luminance is computed out of the box for any image that you
have already rendered and for any render settings. Illuminance can be computed by the Adaptive
BSD engine - as a byproduct of the irradiance map. In addition to the false color rendering,
user can select regions of interest, find the extreme points and check the distribution of values
with the available histograms.

But we didn't stop there! We developed another add-on, where Thea can produce a html report
that you can easily share! Please, check the screenshots below.

We are very glad to see this coming out with our next public revision, a feature available in expensive
applications but now with the accuracy and fidelity of Thea. ;)
ams_ibl_screenshot_half.jpg
Luminance analysis for the advanced material simulation scene.
ams_ibl_screenshot_half.jpg (86.03 KiB) Viewed 14089 times
ams_ibl_report_screenshot_half.jpg
Corresponding report.
ams_ibl_report_screenshot_half.jpg (101.44 KiB) Viewed 14089 times
penthhouse_screenshot_half.jpg
Luminance analysis for a penthhouse (modeling by Claudio Pilustrelli).
penthhouse_screenshot_half.jpg (111.57 KiB) Viewed 14089 times
penthhouse_report_screenshot_half.jpg
Corresponding report.
penthhouse_report_screenshot_half.jpg (129.54 KiB) Viewed 14089 times
Science may limit knowledge but should never limit imagination - Bertrand Russell
User avatar
saurus
Licensed User v1.5
Licensed User v1.5
Posts: 1080
Joined: Sun Oct 11, 2009 10:12 am
Location: Serbia
Has thanked: 32 times
Been thanked: 39 times
Contact:

Thu May 19, 2011 3:40 pm

Thank you! This is great...remember it from Lightscape. Is it accurate like Lightscape used to be (radiosity)? Could it's numerical results be used in lighting design documentation, or just as roughly conceptual tool?
User avatar
Panga
Licensed User v1.5
Licensed User v1.5
Posts: 542
Joined: Mon Jul 27, 2009 3:32 pm
Location: Lyon - France
Has thanked: 0
Been thanked: 0
Contact:

Thu May 19, 2011 3:56 pm

Hi Giannis, and thanks for this nice feature ! I have a little question about it :

is that feature will be possible to use with IR, because combined with the region option it could be great in order to tweak lights !?
User avatar
Hieru
Licensed User v1.5
Licensed User v1.5
Posts: 1975
Joined: Fri Jun 26, 2009 11:47 am
Location: UK
Has thanked: 79 times
Been thanked: 27 times
Contact:

Thu May 19, 2011 5:07 pm

Forgive the stupid question, but what are the practical applications of this tool?
User avatar
Tomasz
Thea Developer
Thea Developer
Posts: 8201
Joined: Fri Jul 18, 2008 5:09 pm
Has thanked: 111 times
Been thanked: 62 times
Contact:

Thu May 19, 2011 6:56 pm

Hieru wrote:Forgive the stupid question, but what are the practical applications of this tool?
It is especially good for those who design lighting and architects. If you use IES lights from lighting manufacturers you can easily tell whether they will lit a room efficiently in reality. For example - work surface should have illuminance of 200 lm/m2 (=lux) ≅ 20 lm/ft2.
User avatar
giannis
Thea Developer
Thea Developer
Posts: 7985
Joined: Sun Jul 06, 2008 8:25 pm
Location: Athens, Greece
Has thanked: 11 times
Been thanked: 6 times

Thu May 19, 2011 7:23 pm

saurus wrote:Thank you! This is great...remember it from Lightscape. Is it accurate like Lightscape used to be (radiosity)? Could it's numerical results be used in lighting design documentation, or just as roughly conceptual tool?
Yes, it is quite accurate; the luminance computation especially the one taking place by the unbiased engines, is as accurate as it can be. The illuminance depends on the tuning of final gathering which can trace more than just diffuse interreflection; in addition, photon map caustics can be added, a feature also missing from traditional radiosity solutions.

@Panga: luminance false color image can shown by IR; illuminance is only computed by BSD (in darkroom).

The false color rendering, is an easy way to find high energy areas (perceptually) in your render and vice versa, dark areas that need to be illuminated better. Lighting design and engineering is a whole art on its own, such a feature can give a good visual and numerical help when making decisions.

best wishes
Science may limit knowledge but should never limit imagination - Bertrand Russell
Jakchit
Licensed User v1.5
Licensed User v1.5
Posts: 140
Joined: Sat Sep 25, 2010 5:13 am
Has thanked: 0
Been thanked: 0

Fri May 20, 2011 1:02 am

I hope to someday be advanced enough to understand what this even means :) I love it though.
User avatar
GreenUser
Posts: 1131
Joined: Sat Apr 24, 2010 8:09 am
Location: California, USA
Has thanked: 0
Been thanked: 0

Fri May 20, 2011 10:54 am

The false color images are a nice effect. I'll probably use it one day for some cool effect.

From the lighting side I kind of thought this could have been done before by looking at the full color picture and seeing the hot spots in the image. I guess this makes it easier when exact brightness is critical. For the lighting to be the same it would seem that having an accurate material becomes all the more critical. If the reflection or diffuse is off then the exact brightness of that object with that lighting will not be the exact same as it would be in real life. Correct me if I'm wrong on any of this.
User avatar
Hieru
Licensed User v1.5
Licensed User v1.5
Posts: 1975
Joined: Fri Jun 26, 2009 11:47 am
Location: UK
Has thanked: 79 times
Been thanked: 27 times
Contact:

Fri May 20, 2011 11:17 am

Thanks for the explanation Tomasz :thumbup:
User avatar
eph
Licensed User v1.5
Licensed User v1.5
Posts: 366
Joined: Sat May 16, 2009 9:27 am
Location: Europe
Has thanked: 0
Been thanked: 0

Fri May 20, 2011 11:37 am

Waw, fantastic news Giannis!! :mrgreen:
Unexpected and great to finally have a good (and usable) Radiance-like renderer in the field. Thanks a lot!

And yes, it can come in very handy for office / school / ... design, where certain workspace illumination is needed.
Work: iMac Intel i7 3.4 GHz (8GB RAM), AMD Radeon HD 6970M (2GB RAM), OS X 10.9.5 (FR)
Home: Dell Intel i7 3.6 GHz (16GB RAM), GeForce GTX 750 Ti (4GB RAM), Windows 8.1 64bit (EN)
Locked