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•FAQ• How to fake diffuse ceiling lighting ... ?
Posted: Sat Apr 07, 2007 11:52 pm
by deadalvs
hi there...
i've tried a few tests to render a lighting scheme like in this example:
how could i fake this the most realistic to get a speedy interior?
emitters behind frosted glass may be realistic but takes ages to render... my best result was with this setup plus a invisible emitter right on top of the glass to get direct lighting to eliminate noise...
any other stories with success? maybe with an .mxi emitter ?
thanks...
Posted: Sun Apr 08, 2007 1:21 am
by sandykoufax
IMHO MXI is good to this.

Posted: Sun Apr 08, 2007 10:13 am
by glebe digital
I'm with Sandy, used this mxi technique a number of times and it works really well.

Posted: Sun Apr 08, 2007 10:55 am
by deadalvs
super guys, thanks for the motivating words...
is it possible to see some examples ? *pleeze*
what res would You make the .mxi ? (in the end i'll have to render an image 3400x2400 where about 1/4 of the area is visible as such ceiling and floor construction... interior rendering of course...)
?
Posted: Sun Apr 08, 2007 1:22 pm
by glebe digital
No worries.
The scene is lit by mxi only [the ceiling, vdu's and the wall panel in distance].
The light fittings were supposed to bounce light up, but using mxi to fake the first bounce 'instance' had a dramatic effect on rendertime.........14hrs @3000px wide rather than apprx 36hrs with standard emitters & a non-faked 'up-bounce'.........I hope that makes sense

it's confusing me already now I read that back!
Good luck.

Posted: Sun Apr 08, 2007 1:29 pm
by sandykoufax
Good.
It's my 14min quick test render.
sl 8.25 benchmark 31.16
I don't have a good example of the ceiling light.
If you have it in your office, just take a photo and converted it to mxi.
above is just emitter with bsdf.
sl 8.40 benchmark 33.03
Posted: Sun Apr 08, 2007 1:37 pm
by deadalvs
hehe... 14 minutes with the koufax xeon, huh...
thanks guys... looks promising !
Posted: Sun Apr 08, 2007 1:41 pm
by sandykoufax
Posted: Sun Apr 08, 2007 2:10 pm
by deadalvs
guys - You're worth umglektohbekniridnium !
Posted: Sun Apr 08, 2007 3:49 pm
by b-kandor
sandykoufax wrote:Good.
It's my 14min quick test render.
sl 8.25 benchmark 31.16
I don't have a good example of the ceiling light.
If you have it in your office, just take a photo and converted it to mxi.
above is just emitter with bsdf.
sl 8.40 benchmark 33.03
Hi Sandy,
How did you create the lights in your first pic? It looks great!
Kandor
Posted: Sun Apr 08, 2007 3:56 pm
by deadalvs
nice... i get a speed increase of factor 20+ !
*lala*
* * *
to get this light ? just take a photo of the light (.jpg from the web), import it into mxcl-d, tweak the ISO and shutter, then export an .mxi
use this .mxi file in a .mxm as emitter and there You go !
the only problem is the iterative process to set the iso and shutter to realistic values
Posted: Sun Apr 08, 2007 5:16 pm
by sandykoufax
Yes, deadalvs is right.
http://www.lampland.co.kr/ino/products/ ... tmidname=G
Above is the original photo.
I just copied this picture and skewed in photoshop.
Then, converted a mxi file.

Posted: Sun Apr 08, 2007 5:26 pm
by deadalvs
hmm, does any light engineer know if large panels of LED light exist that radiate near zero heat and give as much light as a normal panel ?
i will have a problem with minimizing the dimensions of floor and ceiling construction with technics ...
any idea ?
* * *
thanks !
Posted: Mon Apr 09, 2007 3:44 am
by michaelplogue
Hmm... I'm not a big fan of LED lighting - the light they emit tends to be very dim and generally emits icky colors that are unpleasant to work under. You may want to look into fiber optic lighting. It's becoming popular for home lighting - especially in cramped spaces like cabinets. However, I don't think they would be the best option for lighting huge areas like you would with a standard panel light. FO lighting is also quite expensive - though LED bulbs are also pretty pricey.
Here's and article from This Old House that talks about FO lighting....
http://www.thisoldhouse.com/toh/knowhow ... 83,00.html
Posted: Mon Apr 09, 2007 7:09 am
by ivox3
I'm gonna have to start calling you Crafty Sandy ...... using 'skew' , ....that's good.
The web is your oyster .....
..or maybe your more like a Maxwell MacGyver.
lol ....