No argument on the making existing tools work, but in terms of tool design you 
make the erroneous assumption everybody wants to create realistic looking 
renders like you.  I've largely worked on non-photo real projects where those 
extra controls you dislike are absolutely necessary and often not enough.  This 
industry is about making looks and scenarios.  It's not always about recreating 
what you see in front of you.

One of the problems today with maintaining or further developing mental ray 
integration is the old groundwork needs to be maintained so scene files remain 
compatible with the application.  This in turn hurts forward progress because 
in order to get some of that progress requires core changes.

What needs to be done is for the application to be fully exposed at the atomic 
level and users educated to the level required to operate it.  Unfortunately 
that's not realistic as some of the concepts require PhD level understanding 
and a willingness to get deeply involved in the inner workings.  Most artists 
don't want to, or can't go that route.  So compromises must be made such as 
sealing off a few features and exposing only the basic parameters most people 
would need to touch.  The unfortunate side effect is more advanced users get 
blocked from doing what they are capable of doing.  Can't please everybody.

What should've been done from the beginning is make all the shaders very atomic 
and wrap them with the concept of compounds.  Unfortunately that didn't quite 
happen in the case of the architectural shaders other than using mental ray's 
concept of a compound (phenomenon) which is not editable in the UI, and only 
rigidly so from code.


Matt




From: [email protected] 
[mailto:[email protected]] On Behalf Of Ed Manning
Sent: Thursday, November 08, 2012 7:16 AM
To: [email protected]
Cc: [email protected]; Mark Schoennagel
Subject: Re: Mental Ray Features, Integration & Autodesk's failure

On Thu, Nov 8, 2012 at 3:43 AM, Christian Freisleder 
<[email protected]<mailto:[email protected]>> wrote:
What happened to Zap Anderson (aka. Master Zap).
didn't he leave Mental Images and went to Autodesk to help with the integration 
of MR?
http://mentalraytips.blogspot.de/2011/09/this-is-100th-post.html
maybe 1 year isn't enough time to do it in all applications and thats maybe why 
3ds catches up with features, but if he is still there there might be hope.

While Master Zap has unquestionably done a huge amount of good in the MR 
community, and absolutely knows more about MR than I ever will, I think we 
ought to temper our enthusiasm for what he might be able to achieve.  He is one 
person, and if the implementation of his work in AD products is any example, 
even having the benefit of his efforts can lead to mediocre results.

The history of unresolved bugs and poorly conceived workflow in the arch 
materials' implementation is more than annoying. The amount of person-hours and 
CPU-hours wasted by people who simply don't know what all the settings do, nor 
which ones should be used in what situation, must represent a substantial 
fraction of the CG budget of any company that has had to rely on them. The mere 
existence of Felix Geremus's much-improved shader, and the fact that it had to 
be built, after years of complaints unaddressed by Autodesk, by a generous 
individual and distributed for free, is pretty clear evidence of at least one 
missed opportunity.

Technology evolves.  Software-based technology is supposed to be improvable, 
not static. The whole point of the current architecture of computers is to 
allow for changes to be made.  For all of the base shaders in AD's products to 
remain unchanged after 3, 5 or 20 (!) years of steady and proven improvements 
in shader design is shameful. (And yes, I realize that you can't "improve," 
say, Lambert or Phong shading, as they are specific algorithms -- but you could 
for example replace the glossiness code with the better one that came along 
years later, but is only available in the mia and mib shaders.)  How would you 
feel if, say, you had to use Office '95 to this day?  What is even more 
shameful is the fact that Mental Images *has* been improving their code, but 
that the improvements are poorly or not at all implemented in AD's products.

Some might protest that AD (and Avid and Microsoft) have no obligation to 
provide continuous improvement, or add more modern tools as time passes; that 
providing a platform for others to build on is enough.  If that were the case, 
then these products should have been sold that way, as dev platforms and 
frameworks, not as cutting-edge applications.  These packages have always been 
represented as cutting-edge *solutions* and we pay dearly for support.

Look, I know it's easier to market a completely new tool than an improvement to 
an old one.  But AD has an obligation to maintain the viability of the toolset 
they provide.  What if your car had all modern amenities and safety equipment, 
like power locks, air bags, air conditioning, anti-lock brakes, traction 
control, satellite nav, a fancy audio system, but *ONLY* the 1.0 version of 
each of those things -- and *ONLY* the 1.0 version of the throttle (a knob or 
lever, not a gas pedal), the steering (a tiller, not a wheel), the tires 
(unvulcanized rubber with inner tubes), and an engine that required a mechanic 
to ride aboard?  Would you even buy it? Would anyone even be able to drive it 
safely?

As Andy pointed out earlier, rendering is in a way the whole point of the 
exercise. Yet of all the tools in the toolset, it seems to be the one without 
any incremental improvements or bugfixes.  We get whole new tools like FG, or 
IP, but any improvement to those things comes years late if ever.  I'm not 
asking for new features.  I want the features we've had for years to work 
properly.

I want simple, clear workflows and clean UIs. I want default materials that use 
modern algorithms. I want UI defaults that are approximately "correct."  I want 
controls that have actual units (like, say lux, or candelas) when appropriate.  
I want sliders that don't have their meaningful range compressed into 1/50th of 
the width of the slider, or totally off the scale.  I want sliders that *HAVE* 
a scale, for crying out loud (look at Nuke -- some sliders are linear, some are 
log, some exponential -- and they all have tickmarks and numbers).

Yes, it's great to have all the controls available in one place, like the arch 
mat.  But that doesn't change the fact that for 99.9% of real-world materials 
(which is what we spend most of our time trying to simulate), you only need 
*one* color to describe the material color. They don't have separate 
reflection, refraction, translucency, irradiance, and incandescence colors. If 
it's a dielectric, the reflections are *white*, period -- only their intensity 
varies.  If it's transparent or translucent (I'm ignoring scattering here, 
because so do most of our shaders), the transmission has *one* color, not one 
for refraction, one for adsorption, one for "falloff." And of course, and the 
VRay guys remind us, EVERYTHING HAS FRESNEL. And energy is conserved, always.

Sorry for the rant, but my point is this. The mia_arch_mat PPG has 69 
parameters (if you count colors as either 3 or 4 params, you have a lot more) 
and several more that have ports but no controls (like texture coords), and 
*MANY* of them need to be set to produce even a minimally-useful render. It's 
enormously useful to have those params when you need them (if they actually 
work).  But that is rare.  Most materials that we make with the arch mat could 
be very well described by:

 1.  color (RGB)
 2.  luminosity, if it glows (scalar)
 3.  adsorption distance (if transparent or translucent) (scalar)
 4.  IOR (complex please) (1 or 2 scalars)
 5.  refractive diffusion (scalar)
 6.  reflective diffusion (glossiness) (scalar)
 7.  reflectivity (scalar)
 8.  bump/normals (3-vector)
 9.  UVW values (3-vector)
 10. Opacity/output alpha (scalar)

That's IT.  Most of the time you don't need sampling or optimization controls 
-- you want the samples = "enough to not buzz" so obviously the more diffuse 
something is the more samples need to be taken, and when *wouldn't* you want 
your shader to be "optimized" as long as it doesn't add nasty artifacts?

This looks like the basic Lambert or Phong controls, doesn't it? But those 
legacy shaders don't actually interconnect most params internally, so changing 
IOR doesn't affect reflectivity, for example, and energy isn't automatically 
conserved.  So they're pretty much useless for modern rendering of 
physically-plausible materials.

Now, I can build (and have built) presets in the render tree that take care of 
much of this.  But that's messy, frightens the kids, and is ridiculously slow 
to load if I make it a compound and give it a clean PPG.  Not to mention, not 
very optimized. We need compiled code, or at least a UI that doesn't bog down 
traversing a graph with lots of interdependencies. Mental Mill may have been a 
step in the right direction, but it was a small step and is deprecated now 
anyway. So is MetaSL.

So.

Please, Autodesk & nVidia:  fix this.  I don't care how we got here or who was 
responsible. I don't care if people messed up or not.  I just want to be able 
to use the tools in which I've invested many tens of thousands of dollars and 
virtually all of my waking hours for 15 years.  I made those investments, in 
Softimage and Mental Ray, deliberately, in every sense of the word, because I 
believed that they were the best tools available.  They may or may not be the 
best tools available now, but they are my tools and I need you guys to step up 
and make them work properly. That probably means that you need to work together 
rather than independently. I'm glad to hear vague talk that that is happening. 
Here's hoping that you all can follow through on this in time for all of us out 
here.

etm






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