Jump to content

MR: Ambient Occlusion shader


nisus
 Share

Recommended Posts

Hi All,

 

I'm using MR but my scenes lack the 'dirtmap'/'gi*'/'ao*'-look imho... I'm searching to add more of this into my scenes...

 

As far as I've noticed, the skylight/IES sky does not effect an exterior scene using MR. I've played around adding AO-shaders in the lighting Mental Ray LIght Shaders pad, but with no useable results. I can make images that sort of look like AO, but I'd like to add this into the same pass using MR.

 

Anyone good a clue upon a good/useable workflow?

 

Any tips are most welcome.

 

rgds,

 

nisus

 

*GI= Global Illumination

*AO= Ambient Occlusion

Link to comment
Share on other sites

"I'm using MR but my scenes lack the 'dirtmap'/'gi'/'ao'-look imho"

Please , try not to use such hermetic jargon!

I don't get a thing of what you mean!

Thanks

 

Hmm, I don't think any of his terms would fall under the category of 'hermetic' which actually means:

 

1. Completely sealed, especially against the escape or entry of air.

2. Impervious to outside interference or influence: the hermetic confines of an isolated life.

3. often Hermetic

a. Mythology. Of or relating to Hermes Trismegistus or the works ascribed to him.

b. Having to do with the occult sciences, especially alchemy; magical.

 

If you don't know any of his terms, or have never even heard of them, then maybe it's best to leave it to somebody else to answer.

 

And on that note...Nisus, sorry I don't use MR so I can't help you out. I just found the 'jargon' comment a little inappropriate.

Link to comment
Share on other sites

"I'm using MR but my scenes lack the 'dirtmap'/'gi'/'ao'-look imho"

Please , try not to use such hermetic jargon!

I don't get a thing of what you mean!

Thanks

 

gi = global illumination

ao = ambient occlusion

dirtmap = a mental ray map

 

not that difficult, it's a correct way to call things in a kind of 3d related techincal vocabulary.

Link to comment
Share on other sites

Hi Nisus, as mbr said you need to enable FG to get skylight to work. As for amb/occ shader effect, I use a standard material, with a/o map as diffuse. Then play with it's settings, but keep it's sample count reasonable(

 

The pic is with 8 samples in a/o and 1000 in FG. Render time 37secs

You can also enable 'material override' in processing panel, which will use the a/o mat for the whole scene.

 

Hope it helps some and post some pics of your effort!

Link to comment
Share on other sites

Hi all,

 

héhé on the vocabulary... I simply like these shortcuts, because it's handy and almost slang for regulars... like someone said... don't understand it??? Leave! ,-p

 

Vertexart: I've tried the use of the shader in the diffuse slot, also in the self illumination slot, giving good results for a map by itself, but I want it 'automatically' overlayed over all materials... a bit like an RGB-multiply overlay... but without having to remake all scene materials... Any clue?

 

rgds

 

nisus

Link to comment
Share on other sites

a bit like an RGB-multiply overlay... but without having to remake all scene materials... Any clue?

 

No, sorry. IMHO, I don't think you can without remaking the materials. Or if U use the good old method of PS post production:)

Because dirtmap renders existed even before MR3.3, I kinda got used to this method.

Render the image with original materials, then re-render with a/o mat, and then blend them in PS or any other.

you can also try rendering the elements within Max.

 

Cheers

Link to comment
Share on other sites

as vertexart said i don't think there are other methods then passes to render with dirtmap. the other way, without an ambiebt occlusion pass, is, as mbr said, to use skylight and fg (yes, you need fg to make skylight work).

as for the attached image: skylight+fg (if it looks close to what you're after).

Link to comment
Share on other sites

Hi all,

 

I understand the problems and possibilities...

 

I got LOTS of issues using FG (with glass, photons, and a huge rendering time) since moving from max6. Basicly, my setup in max 6 was ONLY FG (no GI), in max 7 it's ONLY GI (no FG)... things have changed...!

--> so I need some AO somewhere... Read somewhere it 'might' be possible adding an omni (ambient only) with an AO-shader in the MR lighting setup?? Anyone knows about a workflow for this technique?

 

But I don't take NO for an answer ,-pp Still looking for a way, just because it would be a great timesaver ,-)

 

nisus

Link to comment
Share on other sites

Tnx rivoli.

 

The first link is the technique I tried (with the MR-shader...)

Second is one have read earlier today (and months ago)... unfortunately, it's NOT about workflow... Imho tutorials NEVER are, which make them SOOO BAADDD... tutorials are about this an this setting for this particulare scene... turns one head into a mess! I want workflow tutorials... ain't that right Ted!

 

nisus

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...