Mental Ray - Shaders

#921

trolldeg, can you post your settings on lighting? I don’t know what type of lights or shadows your using, or if your using GI ,etc…

#922

Hello Trolldeg

i’ve had a problem like this before. It seemed that the hdr image wasn’t a high enough resolution for the scene size and detail. The way i resolved my issue was to use gi and fg together, with slightly increased samples of gi, and to slightly blur the hdr image. Give it a whirl, might sort your problem. You could always increase the no. of lights in your scene and not use fg, maybe a little self illumination and be sure to add photon basic shaders to the materials as this greatly increases photon emission when rendering with large amounts of lights. Also a sphere with normals inverted, encompassing the scene stops photons from not storing and casts them back into the scene for extra illumination.

Phil b

#923

For the past few days i hav been trying to use photonshader, but could not find it!
could u please show how to use photonshader with max material,
which slot should be used,
a screen-shot would be really nice!

thank u…

saiko

#924

@saiko - http://www.cgtalk.com/showthread.php?s=&threadid=117519&perpage=15&pagenumber=1

There’s a test scene using the photon shader, is that what your referring to? Or something different?

#925

yes thats what i want !

i think this is the best and certainly the most informative thread i hav ever seen !
thanks a lot folical9 for starting the thread and guiding so many 3dmax6 user to use mental ray.

i myself can’t even imagine eploring mentalray without this thread !

now i am waiting for ur guidence about indoor scene in mental ray.

i also think if u could compile a documentation from this thread about how mentalray could be used for the basic needs like what the renderers like brazil, vray ,finalrender come with. i mean a compilation of basic materials like glass, crome, carpaint, skin or SSS material tutorials and some indoor photon mapping tutorials.
it would really help the new mentalray users to use it as a subsitute of all those renderers.

thanks once again …

saiko.

#926

Originally posted by folical9
trolldeg, can you post your settings on lighting? I don’t know what type of lights or shadows your using, or if your using GI ,etc…

here are my render settings:

perhaps I need to explain some more, I’m not using the hdr map for lighting, just for getting reflections in the leather material.

Additional info: Skylight with solid color, and one mr Spot (or omni?).

#927

Have you tried increasing trace depth? I tried setting up enviroment, in material and in global, both were working fine without artifacts like you have. Have you tried making a new scene and starting it from scratch?

And btw, this thread is getting a bit too long. It doesn’t bother those who have been along since the begin like me, but what about those who are just starting to read this huge thread. I check the first pages of this thread and some of the images have already started to disapper, but thx to folical9 who still has all his picts up, the thread is still readable. But I belive somebody should gather all important and usefull information of this thread and write a “tutorial” about it. Something like “mental ray in max6 for beginners”.
If nobody else wants to write it, I could try, yet I’m not the best choise because I have bad spelling and my skills with mr aren’t near as good as folical for example.

#928

trolldeg,

What does your render look like if you turn off the min and max radius, and turn off use falloff? Also, what type of shadows are you using on that omni?

#929

Hi.
Where I can find diffraction “mr” & “dll” files.
I use 3d max 6.

#930

Originally posted by folical9
[B]trolldeg,

What does your render look like if you turn off the min and max radius, and turn off use falloff? Also, what type of shadows are you using on that omni? [/B]

the artifacts are still there but are a little more blurry. shadows for the spotlight (it turned out to be) are the standard shadows you get when you create a mr Spotligt, the dialog says ‘raytraced shadows’

#931

Hey guys, great thread, it actually made me use MR as favourite render now. I’m looking now to remake a visualisation i did of a lamp i rendered with vray. But the problem i get is to simulate glossy refractions, i tried several things but i can’t get the same effect i had with vray, here’s a link to the vray rendered version, anyone knows a solution ?

#932

Hey guys, great thread, it actually made me use MR as favourite render now. I’m looking now to remake a visualisation i did of a lamp i rendered with vray. But the problem i get is to simulate glossy refractions, i tried several things but i can’t get the same effect i had with vray, here’s a link to the vray rendered version, anyone knows a solution ?

#933

i’m just plain stupid, just figured it out : glass(lume) material with transparency blur on :slight_smile:

not exactly the same but i’m happy with it

#934

I have located a MR Diffraction shader that was written for Maya.

http://animus.brinkster.net/index.html

I have edited the .mi file as follows:

MI file for Diffraction Mental Ray utility

Version: 1.0 for Mental Ray Diffraction Shader 1.2 by Daniel Rind

Created: 12.05.2003

Author: Robert Mehofer

declare shader
color “Diffraction”
(
color “input”, #: default 1.0 1.0 1.0
color “refract”, #: default 0.0 0.0 0.0
color “filter”, #: default 1.0 1.0 1.0
scalar “glossy”, #: default 0.0 softmin 0.0 softmax 1.0
integer “samples”, #: default 0 min 0 softmax 1000
scalar “ior”, #: default 1.0 softmin 0.0 softmax 100.0
integer “max_depth”, #: default 1 softmin 1 softmax 10
scalar “aberration”, #: default 0.0 softmin -10.0 softmax 10.0
scalar “saturation”, #: default 1.0 softmin -10.0 softmax 10.0
scalar “transpose”, #: default 0.0 softmin -1.0 softmax 1.0
scalar “absorption”, #: default 0 softmin 0.0 softmax 1.0
boolean “absorption_enable”, #: default 1
integer “exhaust_mode”, #: default 0 min 0 max 1
color “exhaust_color”, #: default 0.0 0.0 0.0
scalar “normal_blend” #: default 0.0 softmin 0.0 softmax 1.0
)
version 1 apply texture
end declare

All i did was add the “apply texture” to the line above end declare.

If anyone figures out how to use it maybe they wouldn’t mind posting a scene? There is an .jpg at the Upload site that look interesting does anyone know where that scene file is? lol

Zom.

#935

hi zom,

Like most shaders coming over from maya, ie. dirtmap, they have scaling issues within max. I’ve tried this shader out myself and it always seems to be speckled, like it was painted by a pointelist. I did see this image you’re talking of (the diamond with diffreacted colors on each face) but can’t seem to replicate it. In fact, at first i thought it was a sampling issue within the shader params and bumping them up helped a little but soon became unrenderable and still no-where near like the image i saw. This surely can’t be the way, so i too would like to see that scene file, if it’s about ?

Phil b

#936

hi killerbee,

can you post your scene setup to see if we can get it looking similar or is it commercial, not for others to touch stuff ?

Phil b

#937

Howdy, all. Just bought Max 6 a few weeks ago, and I am very pleased. Especially since I was using (don’t laugh) trueSpace (stop laughing) before. I’ve been following this thread, as I’ve been involved in making shaders for trueSpace. Awsome topic, and thanks to everyone for posting. I’m loving the parti volume sss effects. I’ve been experimenting for the last week. I’ve come up with either warm cheddar cheese or Dial soap. What do you think?

I’ve found it’s useful to use the logarithmic exposure function to get a good balance of light, as without it I get good sss, but overexposed surfaces. I’ll try and post a scene later if anyone’s interested.

#938

certainly would be! :applause:

#939

that’s pretty nice. I think with a little surface roughness it make a great cheese, as it is it a great bar of soap. I’d certainly be interested in seeing your setting or post of a file.

Eric

#940

Thanks. I’ll post a file this weekend. Right now I’m still working some things out. I don’t remember if this has been discussed yet, but scale seems to play a big part in the sss effect (and indirect illumination in general). In my scene, I was working in decimal feet, and realized my main block of cheese/soap was about 3 foot cubed. Well, since I’m not planning to feed an army of mice or wash an elephant, I thought I’d scale the meshes down to a smaller size. Here’s the reslult:

HUGE difference! I’m pretty sure if I scale the settings on the material down as well, things will go back to normal. Also, this means if you’re using others materials, and their system units are set up different, you may get different results.