3dmax Mentalray question

[kilmyneo]

Hello im very new with mentalray ilumination.
I have a moving background tracked in boujou, a matte shadow plane and a teapot in 3dmax...very simple scene, how can i do to do a very fast render with ¨realistic¨lights and shadow?, so far iv´e done a few previews with bad result.
thanks for help :thumbup:

[Raptor365]

Hi Antonio. I found a link here that might help you. I had a look at it and it should get you going. It's for global illumination.

http://en.9jcg.com/comm_pages/blog_content-art-36.htm

You could also try fake GI as Anhar mentioned...

http://www.dvxuser.com/V6/showthread.php?t=154657

[kilmyneo]

thanks raptor!! i will take a look ;):) i hope this is what im looking for

[kilmyneo]

one more, what can i do to get this kind of ilumination???
http://i38.tinypic.com/29gydv.jpg

[Anhar Miah]

The first one can be achieved with GI (real or fake)

The second one looks like "Ambient Occlusion" google for it.

Anhar

quick example of Ambient Occlusion
http://www-viz.tamu.edu/students/bmoyer/617/ambocc/

[oneinfiniteloop]

The second is definitely AO, you can easily find some tutorials for it. I used to have a few bookmarked for Mental Ray for Maya, which I'm sure the settings are roughly the same.

[kilmyneo]

great! this is the kind of illumination there i want to use with my boujou composition...i will look for it, thanks both!

[Matt Grunau]

CGTalk had a great deal on this subject, and with a quick search there, I was able to find tons. There are even some specific to Mental Ray.

Hope that helps, and enjoy!



http://forums.cgsociety.org/search.php?searchid=1251773

[Matt Grunau]

The first one can be achieved with GI (real or fake)

The second one looks like "Ambient Occlusion" google for it.

Anhar

quick example of Ambient Occlusion
http://www-viz.tamu.edu/students/bmoyer/617/ambocc/



Very informative post, as always. Thanks Anhar!

[kilmyneo]

hello guys, i dont want to start other post for maybe a newbie question... i was making an object and suddenly my uniform scale icon can´t work, i tried to scale a box but doesn´t work.
http://i38.tinypic.com/2akflfb.jpg

[Ironman]

"+" or "-" should increase or decrease your handle size :)

hello guys, i dont want to start other post for maybe a newbie question... i was making an object and suddenly my uniform scale icon can´t work, i tried to scale a box but doesn´t work.
http://i38.tinypic.com/2akflfb.jpg

[kilmyneo]

doesn´t work :(

[kilmyneo]

ok i could fix the problem! ...i did a search and i found there it was an internal problem that fix deleting the 3dmax.ini file, thanks guys!

[kilmyneo]

hello guys me again, if i have a daylight system but i want to render without the mr physical sky...the problem is when i try to import the jpg sequence inviroment from boujou the daylight system will not work fine right? what can i do to have the jpg sequence and a good daylight????:dankk2:

[Raptor365]

Are you loading the jpg sequence into max's Rendering->Enviroment background, and that's causing your lighting problem? Not sure if I understand the question.

[kilmyneo]

Hello Raptor, yes im loading the jpg sequence in Rendering->Enviroment background for mix it with the boujou camera tracking, but if i select the daylight system to give this kind of illumination to my obects this daylight couldn´t not work becouse (jpg sequence) it would be replaced by mr physical sky.

[Raptor365]

Ahhh. Maybe what you could do is render two seperate passes.

First render out just the background without the physical sky.

For the second pass, delete the background and turn the sky on. Then render the foreground objects along with an alpha channel.

Then you could combine the 2 in post using Rendering->Video Post or use your NLE.

---
Here's from the help file for rendering with alphas...

"To output a rendered image with alpha, save in an alpha-compatible format such as TIFF or Targa. With Targa, the default settings include saving alpha; with TIFF, be sure to turn on the Store Alpha Channel check box."

[kilmyneo]

yes ;) this is a good solution ;) i will try , thanks for your time to response my post!

[kilmyneo]

hello, me again, i tried to achive what you told me but i can´t match the shadows becouse i have two different renders, i mean, two different kind of light in the first render i have skylight plus targetarea so that way i can use my jpg sequence, but in the second render i must to use the daylight system to achieve a realistic light, i dont know if im missing something here.

[Raptor365]

The first render as I suggested concerning the background only, you can probably skip.
If as you say it's just footage that has been tracked already, and any foreground obects added to it, with a tracked camera will match. So just skip rendering the background because you already have it and it's not going to change.

The second render is where you add your sky lighting and bring in all of your foreground objects. Render those with an alpha, as long as the sky is not included in the alpha, which I'm sure it won't be. If the sky gets rendered in the color (3dsmax diffuse) part of scene also, it doesn't matter because the alpha will occlude it in the final composite.

Your shadows should only affect the ground and surrounding objects, not the background, unless it's a terrain. That's another issue. I assumed it was a general outside scene.

If your still having trouble, can you post a pic of your background and mention what's happening in the scene? Or PM me if you don't want to post it.
I'm not sure where your going wrong and maybe your scene is not what I presume it is.