Mental Ray - Shaders

#4005

Well Kristo Vaher that is a lot more close than i ever got my mats. it could use some tweaking but that’s because os the use i want to put it to, but its very realistic. thanks

#4006

Glad I could help :slight_smile:

I pretty much jumped out of my Chair at siggraph when they demonstrated this as a “feature” of teh self-illum/glow of the A&D material.

 That is so totally backwards to the design intent. This is [b]not[i] object lighting[/i][/b][i], [/i]never was claimed to be. It is actually primarily intended for the [i]exact opposite[/i], i.e. NON-illuminating objects.

Thank you, that’s what I actually thought when I read some documentation about it, that it can be used for non illuminating objects, but looking at the demonstration videos and seeing it listed as a ‘new feature’ literally made me confused.

Because without it being area lights, it is essentially the same thing as Max 9 with Glow shader or Output in Illumination slot. That’s why I thought there’s more to it since it was advertised as one of the major new mental ray features. It’s good to have the FG-off feature on it though, without needing to create basically same light look in post after rendering, but that’s seemingly the only difference with Max 9 mr. It’ll be handy, I just was secretly hoping for an actual mesh light objects with light emitted from surface normals and their interpolated density. Something new mr features demonstration video convinced me would be there, but perhaps in the future. I’ll keep my hopes up.

Thank you for clearing all that up Zap, appreciate it :slight_smile: Is there a specific reason why mental ray has stayed away from object lights?

#4007

You did help, i’m very new to this and i probably won’t have a similar result to you’res but now i know what and how to tweak.

Great way to learn though. :smiley:

Edit:
Well it’s harder than i thought…
Will post when i get some decent results.

#4008

Yes. Physically incorrect “object lights” is trivial to implement (mental ray has had them for a long time)

Physically correct “object lights”, that does not mean “bring the noise” are very difficultto implement. And at least for max, the product designers do not want to introduce features that at least can be used physically correct.

You can do object lights in max with the francesca geo shader trick, but you’ll quickly see it isn’t terribly useful and more gimmicky than an actual useful tool. Either you have a non physical falloff (like linear, or none), or the noise leveles (or render time, to combat them) are prohibitive.

/Z

#4009

Still coudn’t do it, you said that it has no diffuse color, so if i put the diffuse value to 0 i get black no matter what. I tried to put it near some other object with different shaders (chrome, car paint and a brick texture+bump) but still black no reflection whatsoever.
Oh all this used with mr Sun.

#4010

I’m still trying to work out this mixed material type in Mental Ray. I was able to get around the caustics problem by using the ‘material to shader’ and sticking the Blend material inside the diffuse colour slot of an A&D material, and then doing the alpha map on that material, but now its seems punishingly slow to render. Also, I find that using ‘material to shader’ produces slightly different results than the actual material and it’s harder to control the look.

I had another run at JS_Multilayers but it seems to put me in the same boat - having to use material to shader because it doesn’t seem to mix actual materials. Does anyone know of a different way to do this that is more efficient? It seems like a simple thing - I must be missing something obvious. I really need the equivalent of a Multi subobject material, just one that can be weight-mapped instead of split by material IDs.

Any help would be much appreciated.

b

#4011

This is strange, you’re saying you’re not getting any reflections? You do have reflections spinner right up on 1.0 and color as white right?

Oh and I made a little DGS mistake there, actually it’s better for you to use Diffuse, set it to white (or barely gold’ish white, some white gold has this slight subtle gold look to it) and give it a minimal weight value (like 0.1 or 0.2). Make sure you use minimal roughness. Reflections must be 1.0. Thing is that I thought too old-school about it, thinking that since I had 1.0 on reflections you won’t need diffuse, actually it’s simply a weight value of the overall behavior, use minimal diffuse on white color.

I’m not exactly sure how mr deals with physically correct light behavior (or more exactly - in what order), overall it means that the total sum of light that hits the target must be reflected (glossy and mirror), diffused or refracted (mirror and glossy) the same 100% that originally hits it. But basically you need majority of the light reflected glossy and small minority of the light make up the white’ish surface. If you have diffuse too high above 0.2, then you’ll end up with pearl’ish surface since diffuse takes too large a role.

Could you possibly make a screenshot of your base material settings? (Diffuse and Reflection) Since the problem lies there most likely. Though I’m still not sure why you’re having problems not seeing any reflections. Make sure you have Ray Tracing enabled under Renderer settings (one of the tabs from the Render menu) and that it’s ‘trace depth’ is not 0 (you need a minimal of 1 for trace depth for reflections to show up)

#4012

Ok n00b question, i have the ray tracer enabled, it auto-enables when i choose the mental ray render. And the max depth is 6.
With what shader do you start to work on? i use the standart and to reduce the diffuse i have to use the maps, but in the maps i get 1-100 choice and you talk about 0.65 glossyness and 1.0 reflection. what am i missing?

Anyways a did some googling before, and i came across this tutorial.

http://www.tresd1.com.br/conteudotutoriais.php?t=14616

Its in brazilian but still i did everything there and still it didn’t worked. so i really must be missing something.

#4013

A&D material of course. It’s not recommended to use Standard max materials for mental ray, mental ray does convert between the two very well but it’s like sawing your own feet off once you want to tweak the subtle details.

Change the material to A&D and you’ll get all the properties I’ve been talking about. Since you seem to be really new to this, I recommend you read through the help documents that come with Max about mental ray and it’s shaders. It’s a really tough renderer to start learning if you don’t have much rendering experience in the past, and it benefits for you to get to know the basics.

I’m recommending a focal press book “Rendering with mental ray and 3ds max” (by Joep van der Steen). It’s a good book for mental ray beginners and intermediate users, and offers some good tips for already experienced guys as well. Another good book is with a similar name, “Rendering with mental ray” by Thomas Driemeyer, and it’s an awesome book but extremely difficult for an average user since it is basically a science book (and costs like one). Also, Driemeyers book is for mental ray as the renderer, it doesn’t have anything directly to do with 3ds max. I got my feet off the ground with Driemeyers book, but probably only because back then there wasn’t no other choice :slight_smile:

#4014

Well off i go tomorrow to the local book store. Lol, but anyways, here’s the SS for you.

http://defaultcreation.com/datas/users/5-gold.jpg

#4015

It’s hard to find in bookstores (I assume). You can order it through Amazon though.

And it’s strange the material doesn’t work, could you show the render as well?

#4016

Sure.

Still quite grayish, but as you saw the both colours were white.

http://defaultcreation.com/datas/users/5-gold1.jpg

#4017

Trying out with daylight, yes, it is too gray. I could not see that before since the contrast of white and black on my own tests in the environment did not reveal this issue.

The reason why my render looked good was because the plane below was already white, making it look more white gold than it really was, thanks for pointing that out.

I did a few more quick tests, to get somewhat more close on your renders, increase diffuse a bit more (it takes out more grey as a result - because daylights ground has alot of grey in it and it keeps reflecting all that). I saw good results from 0.5 to 0.8 really. Another thing that seems to be off is the reflection curve, open the BRDF tab and adjust the curve of the reflection to suit your needs. 0 degree reflection 0.8 and 90 degree 1.0 reflection gave me good results. It’s a bit trial and error, since daylight alone isn’t also a good environment to test materials quality, but with these slight changes you should get alot closer to the result.

#4018

Well i got to play with it, and i’m very happy with the results.

Some of the tests
http://defaultcreation.com/datas/users/5-golds.jpg

One thousand thanks Kristo Vaher

#4019 
Create an Arch & Design material and call it "Label base"
Create an Arch & Design material and call it "Label gold"
Create an Arch & Design material and call it "Label silver"

Label base:
Diffuse map: Label_Diff2.jpg
Cutout: Label_Alph2.jpg
Bump: Label_Diff_Bump2.jpg

Label gold:
Diffuse map: Label_Diff2.jpg
Cutout: Label_GoldWMap3.jpg
Bump: Label_Foil_Bump.jpg

Label silver:
Diffuse map: Label_Diff2.jpg
Cutout: Label_SilverWMap.jpg
Bump: Label_Foil_Bump.jpg

Create a Composite Material. Drag "Label base" material as instance to the
Base material box. Drag instance of "Label gold" to Mat1 and drag "Label silver"
to Mat2. Let Mat1 and Mat2 in 100 value both.

Apply the composite material to the object. Adjust the three materials and the 
instanced in the composite will be updated.

I haven't Maxwell render so I can't see if this is what you want achieve. I downloaded
your material from maxwell material site because I was curious about the maps you used. I suppose I applied above them as you did but I am not sure. Also I don't see what are the 4 layers you talk, I used only three as you can see so perhaps I am missing something or some effect?

Edited: I was trying the above with a bottle and I have render errors (the label disappears in some places). So you must apply the composite to the bottle object and then the base material must be the glass bottle and mat1 mat2 and mat3 are the above. Also in the Arch & Design material you need turn on Back face culling on the Advanced Rendering Options rollout.
I would like to know why Composite material don’t works with two objects (bottle object and label object with the composite). I get always bottle object showing in front of composite material. Weird… But with Composite applied to Bottle object it seems work fine .

#4020

. Also I don’t see what are the 4 layers you talk, I used only three as you can see so perhaps I am missing something or some effect?

Bao2 - thanks for the help. To answer your question: when using Maxwell or Fry the best way to make shiny or glossy materials is to have two or more layers, each with the same basic diffuse map, but one set with low glossiness and one with high - then you can weight map the blend to fine-tune how glossy the object is. For that material there are actually 2 different diffuse layers, 3 different gold, one silver, and a neutral ghost mat used to knock out the alphad parts. Sounds complicated, but it really is pretty striaghtforward once you get the hang of it.

In any case, with A&D mat you don’t need all that since most of the per material effects can be done within the one material, but you still need to blend different materials.

I am trying the Composite material again now as per your directions, but it’s still not working for me - I don’t know why. I have the 3 basics mats, and each one works fine on it’s own. When I put them, or any one of them, in the Composite material then right off the bat the alpha doesn’t work. It cuts the material into the label decal, but I still see the rest of the cylinder in the render.

What am I doing wrong?

b

#4021

2008 just arrived today and I wanted to play with Jeff’s tip about using sky portals as area lights. Just a question since the general subject came up in another post too: would this be the “better” way to do area lights in MR? These seem to render very clean very quickly by comparison to the photometric “free area light” I was testing against the sky portal, so it looks like a good candidate to replace area lights entirely. Is that about right?

Sorry if it’s a dumb question but I am still struggling to get my head around the best/most efficient way to create nice lighting in MR that also gives good realistic light reflections for highlights.

b

#4022

Please attach a image with the problem.

#4023

Please attach a image with the problem.

Sorry for the delay:

Here is a (very rough) scene setup with just one A&D material for the diffuse label:

Here is the exact same material loaded as the base material in a Composite material:

Here is the gold foil A&D applied on it’s own:

And here is what it looks like when I add it to the Composite material above, where things get totally weird:

For the last one I chose the “M” option for the Composite Type, but with “A” or “S” it was still messed up, just differently. None worked as I thought it would.

Any clue what I am doing wrong?

Thanks very much for the help.

b

#4024

Yeah, I was seeing the same thing. I just changed the bottle material from a gray to
a glass one and now I have the same issue as you: the rendering is different when it
is in a Composite material or if it is alone. It seems a bug in the Composite material. I hope MasterZap tries to fix this in first service pack :wink:

So the only way left seems the Blend material way you was trying (with the caustic issue also…)

Really we need a better way to do materials in layers error free! :sad: