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View Full Version : Mental Ray Shader Explanations?


CycloneS
07-10-2006, 07:02 AM
Hi,

All i'm looking for is an easy explanation of what the various shaders for mental ray do.


Sorry if this has already been asked. I did some searching and help file for mental ray is pretty confusing.

CupOWonton
07-11-2006, 03:13 AM
Well theres the MentalRay shaders thread stickied at the top of this forum section.

Then theres the 'descriptions' in the 3dsmax help files. Though unless you understand gibberish, good luck reading it.

CycloneS
07-12-2006, 01:46 AM
Yea I read through the mental ray thread. Theres bits and pieces of info scattered in that thread, around the net and in the max help file. I'm gradualy understanding the shaders.

I just wish there were good explanations of what the shaders do... The max tutorials on the mental ray lighting were really usefull though.

CupOWonton
07-12-2006, 01:29 PM
I think MentalImages needs to look into making "Common Sense Shaders" Much like Vrays 1 main shader. You can ajdust the kind of diffuse illumination. You can make it reflective, refractive, bumpy, give it SSS or simple glass fog, etc. The only thing it cant do without a shlack layer is glow. But even if they made several shaders, they could have simpler controlls with better names than r1 g1 g2 etc.

psv
07-13-2006, 08:58 AM
mental ray shaders are more than just materials shader a la vray or surface shaders,,,,use help aditional help, mental ray shaders manual .......a pleasant reading:thumbsup:
cheers
sorin

scorpion007
07-22-2006, 02:30 AM
The problem is that mental ray is a complex system. It was not natively designed for 3ds max, nor any other host package for that matter. It is a standalone renderer with its own concepts and shaders that conform to them, much like Renderman.

Later, they chose to write a bridge to mental ray from 3ds max, maya, xsi, etc. But these bridges are an afterthought. As such they give the end users of 3ds max what 'seems' like a native integration of the renderer and do their best to cover up what goes on behind the scenes. Of course the bridge gets better with each release, but it will never be as tightly integrated as max's native scanline renderer, which was designed from the ground up to work with max.

That is why mental ray shaders are difficult to understand from the general max user's point of view. Certain concepts may not be implemented natively in max, and are added through mental ray support (bridge). Mental ray itself does not know or care how max represents its scene, materials, cameras, etc. Its the bridge's job to convert all that stuff into what mental ray supports. Shaders have to be written for mental ray to mimic the behaviour of max's shaders/texture maps to give the end user the impression that they can just assign max's materials and have them 'magically' work the same way in mental ray. Mental ray doesn't actually need max at all to render an image, all it needs is a scene description (a text file) and a bunch of compiled shaders to produce an image, its just that most people don't want to be writing the shaders and scene description themselves in text.

Vray or Brazil on the other hand are kinda the opposite. They were initially designed to work natively with 3ds max only, and as such only recently have begun releasing standalone versions of their software, with bridges for other packages. To my understanding their standalone versions came as an afterthought, due to public demand. That is why they offer much tighter integration with 3ds max, with simpler to understand materials.

Enough ranting...

Maneswar
08-05-2006, 02:52 PM
Open up the User Reference and type in Shaders in the search field. Find Material Shaders Rollout [mental ray Material] and start clicking the links on the various shaders. First paragraph on each linked page describes what the shaders do and you can then decide how you want to use them to achieve your desired results. You'll also want to check out the mental ray Shaders topic that shows up in search.

Maneswar

KV99
08-06-2006, 10:28 PM
I think MentalImages needs to look into making "Common Sense Shaders" Much like Vrays 1 main shader. You can ajdust the kind of diffuse illumination. You can make it reflective, refractive, bumpy, give it SSS or simple glass fog, etc. The only thing it cant do without a shlack layer is glow. But even if they made several shaders, they could have simpler controlls with better names than r1 g1 g2 etc.

3ds max 9 will come with a 'common sense' shader and mental ray 3.5. It is called something like arch&design. It has all the general settings you would get when combining other shaders and maps.

But the thing is, mental ray is not vray. It is not meant to be, that common sense shader will be basically for those who just want to use something better for rendering than Max'es own scanline and for them to have some material to work with.

True power of mental ray does not lie in such things. It is about few materials and alot of maps, and their combinations. Mental Ray material itself is a very powerful one when used right, and even Max'es own materials work in most ways with mental ray ones (a great achievement in my opinion, usually renderers require their own maps and materials).

And out-of-the-box install is only the tip of the iceberg. Mental ray's shaders are programmable and there are alot shaders out there which are very useful and don't come with straight install. Even better, XSI's and Mayas shaders of mental ray can work with Max as well, which means that mental ray's development has amazing potential considering that it supports three industry leading software packages.

From my personal experience though I can say mental ray is not an easy thing to get into no matter what you do. I mean, I have programming background with C and C++ and even I found it awfully difficult in the beginning.

No there is no great all-in-one resource about mental ray out there. There are two books, but I do not recommend those for the general public. They are useful if you want to know things from the root up, but I do recommend some programming knowledge to do so (and math and physics education should also be at par).

There are a few good DVD's out there. I would recommend Gnomon workshop ones. Yes, they are for Maya, but rendering system is the same and the basics apply to Max as well. Most artists, after a few years of experience, are capable of learning from other programs tutorials just as well as their own program ones, because the phase of 'point and click following precise instructions' is long behind. Do 'NOT' get yourself Evermotion mental ray DVD's. I did, and I consider it a mistake.

Also the mental ray shaders thread is very useful. Mental ray guru Jeff Patton has many good scenes on his website, so reverse-engineering those can teach you quite alot.

Most tutorials in the web out there are also point-and-click based, which really do not teach you much. When it is possible to rely on such type tutorials with other rendering packages, like Brazil or vRay, I do not recommend doing so with mental ray. You really should learn things from the ground up to be effective in such a mess of parameters and settings.

It is all worth it in the end though. I fell in love with mental ray and probably won't let go ;)

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