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View Full Version : My wife says there's nothing wrong with faking it sometimes.

Tugmaster
05-05-2004, 04:19 AM
Get your mind out of the gutter, I'm talking about radiosity. There was a recent thread about lighting and I thought I would share a setup that I use for fake radiosity. I downloaded this car from DMI car models. I hope you don't mind. I use a premade lightdome with 50 lights and inside the lightdome is another sphere that is slightly smaller. I usually use an hdr image in the luminance channel of the smaller sphere for reflections and it adds to the lighting. The results are very close to a radiosity render and my set up gets much more realistic reflections. This shot is a render using my setup. It took 4 minutes to render. I started rendering the same scene using the same hdr image and sphere but without the lightdome and using radiosity with default settings but I stopped the render at 2hrs 45min. and it wasn't even 1/4 done. That would have been a 12hr. render and it would have been hard to tell the difference between the two. It does save alot of time plus you can add another light or two to the scene for more realistic shadows.


http://img17.photobucket.com/albums/v50/Tugmaster/testdome.jpg
bolek
05-05-2004, 04:21 AM
cool, can you post the file please
sketchbook
05-05-2004, 07:40 AM
yup, i also have this light dome. i think i found it in the 3d world magazine special issue or something.

works great. only problem is when you have a room or something, it won't really light the scene very well as it's in a dome. it works best with objects.
fxgogo
05-05-2004, 09:18 AM
Yeah that does look good. I find if you have a distributed scene with lots of camera animation, for example the 'cantralised focus' of the light dome leaves the outer areas no as well lit as the center focus of a single object.
flingster
05-05-2004, 12:07 PM
that is a nice result..even better when you consider speed of result...10outta10 for thread naming also...heh heh.
:beer:
dru
05-05-2004, 01:36 PM
Uau!!! it's a wonderful creation!!!

compliments, also the lights are fantastic!!!

ciao:thumbsup:
Tugmaster
05-05-2004, 02:24 PM
Yes, I got the lightdome from 3D World mag. I just added the second dome and floor plus some compositing tags for some adjustments for the second dome.


Flingster, the bad thing about trying to be funny is it got me to thinking that maybe.........Naw!

sketchbook, your right, there are some limitations to using a light dome but it works great for outdoor scenes also and I have used it in indoor scenes where there was a limited view.

Bolek, if you e-mail me I'll send you the two dome setup.
Deestrakt
05-05-2004, 03:36 PM
very nice result :thumbsup:
i'd like to see your lighting setup also if u dont mind : i send u a mail right away.

edit : i made an error, sent a PM instead. but i guess the result is the same.
tonfarben
05-05-2004, 05:41 PM
Nice render!
But I would like to see the settings for radiosity causing the high render times.
Did you disable "send out radiosity" on the illumination page of each material (except the white skymat and the floor- floor only 50percent)? Also you need to deactivate "catch radiosity" for the skymaterial. and if you use a second sky with HDR, disable both catching and sending radiosity and also catching and sending shadows. Did you disable "cast shadows" for the floor via rendertag? And disable "cast shadows" and "catch shadows" for the sky-object? And, did you set the radiosity-accuracy down to 40% in the rendersettings? And of course only one or two bounces for the 400 rays (100 min and 200 max).
Just a few tips to reduce rendertimes with radiosity.
gmask
05-05-2004, 05:46 PM
Looks great except for the wheels which are way too gray.
Tugmaster
05-05-2004, 06:16 PM
Ha! Tonfarben, that's even a better reason for using a lightdome. I can't even rember where my shoes are half the time and I'm only about 5 more gray hairs away from alzheimer's. Just kidding! I'll try some of your settings for those scenes where nothing but radiosity will do. Thanks!
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