minShaders library for mental ray


Ah, that looks like an interesting and useful feature.

At the moment my physical material shader does not handle transparency at all, but once I add it I’ll definitely try to implement something close to this attenuation feature.


As far as I know, i have not found a way to do this in MR with native shaders.

MIA shader has some advance refraction attributes but nothing like attenuation.


isn’t it a sort of SSS feature?


I think it’s more to do with the volume of the material itself. As light passes through it, the farther it travels the more energy it loses, thereby altering the light’s brightness and possibly color.

I do believe that the dielectric material can achieve similar effects albeit probably with less control.


However, there’s a couple of problems I see with supporting RenderMan publicly:

[li]When it comes to more advanced shaders, RenderMan isn’t exactly a standard anymore. PRMan, 3Delight, Pixie, etc. all do things their own way, which means not only porting to RSL and maintaining that code, but actually supporting different dialects of the language as well…[/li][/quote]

[/ul]Not such a problem. Most things can be worked around with a couple of #defines.
Particularly the minShaders listed on your home page contain not single shader that couldn’t be replicated using RSL shadeops available in all ray-tracing capable RMan compliant renderers (3Delight, Pixie, PRMan) – w/o the need for #defines even.

[li]As if compiling the shaders for the different platforms with MR wasn’t tedious enough, with RenderMan I’d have to compile for every version of each renderer on every OS![/li]
[/ul]Not true. They all use bytecode-compiled shaders. You need to compile one shader for each renderer once for all OSs.

[li]I simply don’t have a license for PRMan, nevermind Pixar’s devkit. :shrug:[/li]
[/ul]Then don’t support PRMan. Btw, having a licenses for PRMan also means having a license for the devkit (they’re one and the same, really). Pixar might give you a free developer-only license, if you asked kindly enough and there was considerable interest from the community for your shaders.

Lastly, the devkit is not needed for your stuff anyway as no custom shadeops are needed to replicate these particular MR shaders’s functionality in RMan.



@Mauritius: Thanks for clarifying. Looks like it may be less work than I feared. :beer:

Nonetheless, porting the shaders and supporting RenderMan compliant renderers remains a substantial investment in time and energy that I can’t afford to make at this point. I’m only one guy and can’t devote all my time to developing shaders.

Once I’ve gotten the MR release out the door and I see a decent return on investment I’ll be able to decide whether a port to RM makes economical sense it or not. At the moment I don’t even know whether the work I’m putting into the MR shaders will pay off in the end.


I think it’s more to do with the volume of the material itself. As light passes through it, the farther it travels the more energy it loses, thereby altering the light’s brightness and possibly color.

I do believe that the dielectric material can achieve similar effects albeit probably with less control.

Is this different from what you get with the refr_falloff parameters in the mia_material_x ?



Mia doesnt actually use the volume of the object.


Hi Stefan,
Any news shaders?


So Stefan, could you explain how you have the minToon shader set up? Ive been wondering on how to create a mental ray shader.


im excited to try this shaders! Thanks stefan!


So what is the final word on these shaders, Stefan?

I've read through 20 pages of people asking for a release, free or paid. And I've also seen you bouncing back and forth if it should be free or paid, or if releasing them would even benefit you at all.

I have to say that this is one of the most confusing threads I've ever read. After page 7, my attention went elsewhere for a while. My point is:

This thread was started back in March, it's now nearing the end of September. Now I'm not a coder, so I have no idea how long the development process is, but it seems that from your previews and even the blatant permanent space that they reside on your webpage that they are ready [i](more or less)[/i] to be used.

Yes, the shaders look great...but after all of this "apparent" demand for these shaders, and 6-7 months you've had to think about how you want to go about releasing these to the community...what is the final word?

You said on 07-27-2009:

At the moment I don’t even know whether the work I’m putting into the MR shaders will pay off in the end.

If this is the question that you keep coming back to with yourself (and from reading 20 dreadfully long spanned out pages on this it seems you have), then the simplest answer is usually the right one… and the most often overlooked. Release it for free to the community, and be done with it:lightbulb…or have the thread closed:).


Hello…o…o…o :slight_smile:

How about inserting some number of processor cores barrier (I’m thinking 8) and have two releases:

a) free - no support, limited documentation - results in some pretty valuable community feedback for future releases/improvements, from that which is or will be future paying customers of option b)…

b) commercial release - full support with elaborate, circumstantial documentation and a ‘lively’ help-desk featurette which should provide enough ‘value for money’ to ensure reccuring investments in upgrades and new releases from paying customers…

Just a thought…

Edit: although Bmoner’s… opinion has a powerful sense of sense…


I sincerely apologize to anyone who feels mocked, confused or was hoping to use my shaders. It was never my intention to cause a stir.

Sometimes real life just gets in the way of the things we would like to do in an ideal world. At the moment I simply lack the time, motivation and resources to release any more software for free or pay.

Feel free to lock the thread.


Yeah, i asked him about one of his plugins on his website and i said i would pay and he pretty much gave me the finger in a pm. owell…


OK, I can understand the frustration over the whole issue and while I don’t necessarily agree with the sentiment, I also don’t think taking this out on me personally by resorting to outright lies and defamation is fair.
I really wanted to stay out of this but wrongfully accusing me of insulting you in a public forum is taking it too far and I will not stand for it.

For what it’s worth, here’s me “giving him the finger” in our PM conversation it its entirety, uncensored and unabridged:

Sybexmed: Can you make website on your toonkits? Would love to see.

Stefan: Sorry, I’m not sure I understand your question. The page about Toonkit
is right here: http://www.minning.de/software/toonkit

Sybexmed: I’m sorry i meant a tutorial on how to use Toonkits or Celulight. Look forward in buying them since i really would like to create toon characters and i dont really like toon shaders in maya.

Pretty harsh words from me there! :rolleyes:

I never bothered to reply to his last message because he was asking specifically about tutorials, which is simply a ridiculous thing to ask for when the software A) isn’t publicly available, and B) in the case of Celulight is proprietary software as I clearly point out on my website.

I did not insult him in any way. In fact I always try go out of my way to be courteous even towards unreasonable (or unintelligible) mails, which is why I find this public accusation all the more unacceptable and I think an apology is in order.

If anyone thinks I was being unreasonable or “giving the finger” to Ruben we sure have different definitions of what that means… :shrug:


Hey man, that was blatant abuse! :wink:

I think what happens ( a lot with Mental Ray and Maya I am finding ) is people post these amazing shaders, pluggins etc ( the core rendering system is a great example ) and talk of a “soon to be released”( free or paid ) but for some reason or another it never materialises. Obviously people are going to be left disappointed.

I think if you had started the thread with " these are shaders I have built, if anyone would like to hire me or my shaders then let me know" Then people would have a different feeling, However your second paragraph was

“Right now I’m considering releasing some or all of the shaders to the community if the demand is there. So… is there anything here that strikes you as particularly useful for your work?”

You’ve had twenty pages of interest but still no release.

(Slightly off topic but probably relevant) I think there is genuine despair at the moment for Mental Ray for Maya users. The current incarnation of it is just dreadful and doesn’t look like its getting better any time soon! So seeing shader packs like theses actually exist but the common user cannot get their hands on them is obviously a huge frustration.

Anyway, this is in no way asking for release or anything of the sort. If I had spent time creating something that was obviously worth money, I wouldn’t be in a rush to give it away for free, but at the same time, after working my way through the 20 pages of thread hoping for a link to download something, I am also left feeling disappointed.


I also just realised that after that long reply I didn’t even mention my thoughts on the shaders.

The short of it is they look great! Things like the RAO shader and your use of it as a cheap sss show how artist based these tools are and the Reptile packs also looks really handy so I’ll keep myself subscribed to the thread and see what happens :thumbsup:


Have strange error when press 6 in wievport, or open UV texture editor. Maya crashes.
Use minObjectID as extra buffer of Deex shader.
Can it be cured?


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