White material using Radiosity

[JPS]

Hi,

I've been strugeling with exterior radiosity for sometime now and I'm just plain sick and tired of it. I can never seem to get the material I want white enough. Even using Radiosity overide..

e.g.

I've created this simple loft model in hopes that some of you guys can play around with it and post it back up to understand your solution. I very much appreciate your help. Please feel free to download the model and play around with it from this web page

I'm looking for a finish similar to this one by cyborg, but with a little more subtle bump on the stucco. http://www.cgarchitect.com/ubb/ultimatebb.php?ubb=get_topic;f=5;t=000244

I'm not sure if he used a GI solution or not but the white stucco is clearly happening. Of course I can do a fakeosity solution and have it be overwith but I'm trying not to cheat.

Thanks in advance.

 

Regards,

J.

[Wojciech Klepacki]

Hi JPS,

I did some corrects to your original "loft" file. I would like to send it for u via mailbox. Please contact me: klepa@opnw.gddp.gov.pl and send me your email. (I have no own web page - I'm too lazy... or too busy...

rgds,

Wojciech Klepacki

[abicalho]

You'll not get a white material, because that does not exist.

 

A rendered material is a function of the color of the material, the color of the lights, and the color that bleeds on it.

 

If you want a pure white material, you need to make sure your lights have NO color, the material is pure white, and there's no material bleeding color on it.

 

And even then, it'll most likely be a shade of gray, and you can adjust the aperture of the camera by editing the exposure control brightness.

 

Hope it helps,

 

Alexander

[JPS]

I've been playing around with it and did the following, although I'm sure someone will come up with a better solution.

 

 

I created a white material map by going to PS and just creating a blank 640x480 jpg then placed it in the material slot and went to the output option of the map and increased it from 1.0 to 3.0. I also went to the daylight systyem and changed the RGB of the sun to white. I did not touch the skyligh RGB although I think if I did it would have made it even whiter. I don't think this is the perfect solution though as you can see on the shaded side of the building you see some highlights of the stucco.

Back to the drawing board.

[ZepSOFD]

Originally posted by ZepSOFD:

JPS,

 

Alexander is right, anything you have in your model will influence the color, is this closer to what you are looking for?

 

 

[edit] I desaturated my grass map so it would not through a ton green on the building [edit]

 

 

Here's your model with the changes I made at least I think it's the right one.

http://www.wellespugsleyarchitect.com/loft.zip

[JPS]

Hey Zep,

In examening your revised file I noticed many more changes then just the disaturation of the grass map with the RGB tint.

For example I noticed that you set up the Refine iterations way up to 30, and you further subdivided the mesh that I had from 3' to 1'...

Also I noticed that the color you used is not Pure white but rather a 204 on all R, G and B...

 

But what Im most curious to know is why in the Environment settings, you turned off the Exterior Logarithmic Exposure Control Parameter, turned down the Brightnes and topped off the contrast at 100??? Is the the correct way to go? I have read many articles saying that the Exterior box should always be checked when using Logarithmic Exposure control for exteriors... If you turn up the contrast so high won't it seriously affect the detail once you start adding more geometry to the model???

 

Anyhow, thanks for the tips, I hope to hear back from you soon.

 

Also if anyone else is interested in posting their tips and settings I would greatly appreciate it.

 

Thanks.

J.

[bigcahunak]

Originally posted by JPS:

...I have read many articles saying that the Exterior box should always be checked when using Logarithmic Exposure control for exteriors...

JPS, I think that even if you read articles, as long as two features aren't combined into one there is no way you "must" use them both in a single way. You should always try things rather than just accept them from an article IMHO.

Anyway, I downloaded your file, and will give it a try later.

RGDS

[nisus]

When using the sunlight, boost physical scale to 90000 instead of 9000.

 

nisus

[Cesar R]

hi, ok I played with you file.

 

Here is it pretty white, let me know what you think. download your file from HERE .

 

This is an image i created a few days ago n Viz

[abicalho]

Turning ON Exterior and Daylight will just change the "internal Multiplier" applied to Brightness, so that you have an easier way to adjust the Exposure when there's Daylight.

 

If I remember correctly, a Brightness of 25~30 is the same as turning on Exterior and keeping Brightness at 65.

 

Alexander

[ZepSOFD]

JPS,

 

There is no right or wrong way of doing this if something seems extreme or not appropriate for your work flow then don't use it there are plenty of other ways that will work for you. I like to work from extreme settings and then work backwards.

 

Refine Iterations:

I would rather use a large value for R.I. then use Regather for removing blotchiness from a material, but there are those occasions when Regather is the only way. I generally use any where from 30-80 for R.I. just depends when the blotchiness clears up.

 

Meshing:

Use what ever you are comfortable with for testing.

 

Diffuse Color:

A 204 white value gives approximately an 80% reflective value, which is close enough for me, but if you need a little more white increase it.

 

Exposure Control:

Like Alexander explained turning on Exterior just changes the scale of the brightness control. (For me)I prefer to do my interior and exterior in the same file(if file size to performance permits) so I find by checking Exterior that my materials change more than my personal tolerance will allow. It's just easier to increase/decrease the brightness to adjust to the scene. I like high contrast images to begin with, so I start with high contrast and I work backwards until my bright materials are not blown out. To enhance the contrast I eliminate the mid-tones unless there is too much contrast.

 

Physical Scale is one of those debatable deals, it controls three things: Light intensity of NON-Standard lights, basically the contrast level of Self-Illuminated materials, and Reflections. I don't use that many non-standard lights so I don't use P.S. for that, the Self-Ill. mat. doesn't seem to reach it's full intensity until around 9000, and reflections seem to be at normal intensity with 100% applied to the reflection slot spinner of the material at 9000. I like to use P.S. to control my reflection value instead of the reflection slot value in my material. I do increase the P.S. value depending on the scene I just haven't had to increase it over 25,000 yet. I also haven't seen any problems with chrome reflections either.

 

My original intent of sending the file was to show that a perceived white diffuse material could be achieved without using a 255 value.

 

I am obviously not a highly recruited CG'er, but I have heard that with a thousand dollars in hand Architecture3d.net will hire me in a heartbeat, but that's another story. So take it all as opinion, collect as much as you can then weigh it all out some will match some will not but at least you will have some information you can base future decisions on.

 

tom

[JPS]

Thank you all very much for your help. It has defenetly been a learning experience. This website has certainly been a great help and a blessing for all of us strugeling CG artist, its too bad to see websites like Architecture3D.net take advantage of unsuspecting soles by what they have done orangeno Hopefully we will always have great people like Jeff looking out for us.

Thanks again.

RGRDS,

J.

[Cesar R]

JPS, Where do you go to school ? or dod go?