'Energy Conservation' in Vray (and others)

#71

Apologies for jumping into a war on my first post. I normally don’t frequent here, but the thread was pointed out to me by a co-worker, and since this has been an active concern of mine I felt the need to lend my voice. While seemingly unpopular I wholeheartedly agree with you guccione. This blind push for physical plausible lighting and energy conservation of the past few years has been a double edged sword. It may seem to make everything more streamlined, but in doing so it is killing the creativity. Lighting a shot is “Painting with Light” and to just delegate this creative practice to the computer is a slap in the face against every artist in the digital and film industry. On set the DP and gaffer go to great lengths to cheat in order to overcome the constraints of lighting physically. Yet, in the digital realm we have none of these constraints, the lighting teams on set would kill for the flexibility that we have. But here we are, happily letting go of the reins and submitting ourselves to the whim of some programmer who has never lit a shot in their entire life.

From a business standpoint, these imposed restrictions on the lighter’s creativity are a Godsend. No longer do you have to wait days for a shot to be crafted, instead you assemble the various 3d models, drop in the HDR and hit render and go onto the next shot. If you are a good little worker bee you’ll have done this for 5 shots before lunch. The shot will look ok I suppose, but it won’t be amazing. But that’s the point isn’t it, keep feeding mediocre shots to the public and they’ll consume them happily because they don’t know better quality exists. This is what has been happening over the past few years and now that we’ve hit a de facto standard of “quality” the studios can now start automating and outsourcing the whole lighting process. Companies like the Foundry are already monopolizing on this trend by introducing products like Katana that further restrict you by reinforcing a “recipe” workflow. You make one recipe and then the suddenly the rest of your shots are supposedly done. Why even hire lighters? Why not just hire data checkers? In fact this is exactly what is happening as more and more of these jobs “data checking jobs” are outsourced.

Now I’m not saying there is a conspiracy, but it does seem incredibly coincidental that all these restrictive paradigms and automatable recipes were introduced by the big software vendors and the big studios which outsource heavily. (Not to mention creating file formats to make these even easier, hello Alembic!) Our creativity is our freedom and we’ve been convinced by companies that our creativity is inefficient and that some algorithm can do it better. Well I’m sick of it and we need to stand together and call attention to fact that these software companies and Hollywood are actively trying crush our creativity, our talent, our imagination and our freedom. We need to get the word out and let them know that this is unacceptable!

We are at the precipice, either we fight back at this trend now or in a few years time there will be no need for us at all!

#72

Painting with light. Exactly. That’s exactly the end goal of the lighting pipeline, and the creative lighting process.

The thing is, in order to effectively do that, you need shaders that ALL behave in a physically plausible, standardized way towards that light. Without that, the most creative lighting in the world is meaningless, because none of the objects you’re directing that light towards will appear to sit together in the same world at all.

You’ve described a film set totally right. The people working on those sets pull out a ton of tricks and use all sorts of techniques to get the look they want. However, they are working with REAL materials, and REAL photons. No matter how absurd the lighting set up and cameras end up tricked out, there is never a concern that the prop artist who made the milk jug has it reflecting 2x more energy than guy who made the cookie jar.

To me as an artist, my dream software package would give me the most physically accurate surface model that can be computed in a reasonable time, and it would ship with a full set of digitally recreated practical lights, along with fully recreated camera and lens systems for all of the common bodies and lenses that I’d want to shoot on.

I would then be doing the closest possible thing to placing real lights among real objects and shooting with a real camera. I’d have the perfect balance of maximum creativity, while also having maximum realism. All of the materials and surfaces would behave like they do in the real world, and my job would be all about lighting it to look as good as possible.

This discussion isn’t about lighting though, it’s about shaders…and at the end of the day, the default state of a shader HAS TO BE that it conserves energy and is a physically plausible surface model. You’ve always got the option of breaking that, adding things together, whatever you see fit…but the baseline absolutely must be physical plausibility.

There isn’t some conspiracy going on between studios and rendering packages. It just happens to be the most globally agreed upon version of what amounts to “best practices”, and happens to be the working methodology that produces the most convincing and most beautiful results.

If I can load up a scene full of assets, and all those assets share sane values that were arrived at with reference sheets for reflectance, roughness, and diffuse values…if all those assets sit in the same world, my job as a lighter becomes more about ACTUALLY lighting. With fully unlocked shading models, my job as a lighter is more about solving and fixing problems, and hoping to still get a few iterations before my time is up with the shot/project.

Without physically plausible assets, you have a much lower chance of success with lighting artistry, and with creatively making a beautiful shot.

Cheating lights all over the place is what it’s all about on a film set. Cheating materials though? You literally can’t do that.

That’s the end goal of energy conserving surface models, and more recent microfacet surface models. They’re meant to give you something closer to a real world lighting workflow, where the materials and surfaces are all physically correct, and it’s up to you to light them nicely.

And if the point was to “keep feeding mediocre shots to the public”, companies like Weta, ILM, Pixar, etc., wouldn’t be investing dozens of millions per year into research that furthers the art of shading, lighting, and rendering the way that they do. Honestly that’s a really ignorant thought. Whether you like the projects or not, these studios are putting some of the most gorgeous imagery onto the screen that has ever been created.

(plus you can always just add things together anyway and not adhere to conservation rules, so I don’t see the big deal at all regardless of how you want to work)

#73

You mean - “it has to be realistic or it can’t be aesthetically pleasing”… someone needs to take an art class.

Just because they can’t, doesn’t mean they wouldn’t, if something came out too dark. As a matter of fact, they add extra lights that aren’t justified by the environment, constantly. Now if someone substituted the prop artists paint with something that required even more of that, don’t expect the light crew to love it.

“artist” and “physically accurate” are barely related. As a matter of fact they’re frequently at odds with each other. You don’t seem to understand that.

But if they can’t, you don’t mind being stuck with them anyway?

And what about all the hundreds of lighters that haven’t learned about all the different types of lighting instruments, the gasses they use in the bulbs, and their color/brightness, or all the camera terminology and how to use them? Some of us have to do more than just light; like model, texture, animate, composite, etc. It appears you desire a tool for your specific job, and you don’t care if that requires workarounds for everyone else.

Sorry, but that’s not up to you. This is about strict photorealism vs. flexibilty. Your argument is no different from saying it’s ok to remove all non-IES lights from the renderer.

Absolutely wrong.

That’s what Victoria already said. Don’t try to imply that people who disagree with you are just paranoid or foolish. That’s bs.

The “I agree with ILM / most people agree with me, so eveyone else can be locked out” argument is getting really tiresome.

So - cg lighting artists should be restricted to what you can and cannot do in real life? Why do you think cg even exists?

You’re completely ignorant if you think profits have nothing to do with it. Energy conservation is NOTHING but a timesaver / automator and/or simplifier. CG artists can’t add their own subsurface scatter, but we can apply energy conservation. All of these studios have bean counters, and programmers, who know absolutely nothing about aesthetics. Additionally, there are tax incentives for software development. That’s why Sony made Katana, and bought/developed Arnold instead of just using maya / renderman for lighting. They even have their own in-house Internet Messenger, and image viewers. Last time I used Katana it was FAR slower than lighting in Maya, and before that, they were using something even WORSE, Banzai (or Burps, I forget which is which). So to claim that all this development is about nothing but ‘beauty’ is naive.

Victoria is absolutely right about feeding mediocre shots to the public. Why do you think that no cg characters have ever looked as real as Davy Jones - from 2006?? Right up until the tiger in Life of Pi (2012). Just look at the Lizardman from Spiderman (2012), it’s blatantly less realistic. How can that be, with all this new tech, I wonder?

#74

@guccione with all due respect man, I don’t think you get it. You can be as creative as you want to be with physically accurate lights. The “take an art class comment” said to someone that I’m willing to bet has way more experience in art and lighting than you is pretty silly. That aside, since I am not trying to insult you and be rude, what he is talking about is the fact that if you are on the set of a film; let’s say a very artistic film. Stop motion, why not, they get very creative with the lights. Those lights in the real world respect physical parameters. likewise, the materials they light, whether plastic toys, or wooden models, or what have you, will be physically real materials. That does not limit any artist that works with practical lights. Likewise, a 3D artist that lights with Physically accurate lights and materials is not limited by that in his artistic freedom. you can do all sorts of neat tricks that still obey real world parameters and get not only beautiful light that feels like light, but you can make it as fantasy or creative or what not as you please. There are plenty of articles and featurettes that talk about how to do it. And not just the big studios. There IS no conspiracy, it is jut the way the industry is going…for the better. The best thing we can do is learn how to move along with it and not let it limit us, but rather, empower us. And if you are going to reply with something like what do you know about art, not only do I do this for a living but did get a degree in animation and studied art for a big portion of my years. I don’t claim to know it all, far from it, I constantly have to learn daily. But such is the industry we chose.

#75

Perhaps some day you’ll explain to me how it is you think you’re “locked out” of anything when you can simply add shaders together however you want.

The renderer isn’t enforcing energy conservation, it’s just the shader. Add as many as you want together; there is nothing stopping you. If VRay (or any other renderer) was really trying to lock you out of anything, they wouldn’t have provided the “Additive Mode” option on things like VRayBlendMtl, and they would be culling and enforcing energy conservation during the rendering process. They’re not. Their provided shading models (correctly) apply masking to the diffuse/reflection/etc. Beyond that, you can do whatever you want…incorrect as it may be.

That’s great, but they can’t. We live in the real world with real materials and real lights, and I don’t see any filmmakers struggling to achieve artistic results because of it. Get creative with your lighting, don’t get creative with completely arbitrary energy return on your shaders.

#76

OP, if you have problems or do not understand something, you do a better service to yourself to ask questions instead of making assertions. CG is an evolving science that strives to be physically accurate at least as a default position. From here we there are many options to break the so called physical accuracy to achieve certain looks. If non realistic rendering is what you need then ask politely and someone will help you.

Also try not to sound like you are mentally insane when interacting on the internet.

#77

What is it about;

  • “I’m just tired of doing workarounds for things that don’t help me in the first place.”
  • “Who else has never gotten a single benefit from this ‘feature’, only extra work, extensive node networks and complicated hacks to get around?”
  • “I know the workarounds, I’m just tired of taking the extra time for no good reason.”
  • “Thanks but I applied the workaround a long time ago. I’m just sick of doing workarounds for a feature that takes control away the artist, and locks it.”

that you don’t understand?

Yes there’s nothing stopping me from setting up 50 shaders, then on #51 realizing that I don’t have EVERYTHING 100% PERFECT, and starting all over again from shooting HDR’s on-set, simply because I can’t turn off EC for that shader. My fault for not being PERFECT, like YOU, and not having a Multi-$Million pipeline. I should be ashamed.

Otherwise, the IMPERFECT lighting/rendering - even at ILM - REQUIRES some flexibilty in the shader. Would you like to forced to render subsurface scatter in every single plastic or wood shader, no matter how insignifigant in the scene it is? Then just stfu.

That’s asinine, you could use point lights as the same argument. “It’s OK that you can’t turn off energy conservation, because they still let you do all kinds of other unrealistic things.” I am the one who’s been pointing out all the unrealistic things we can still do, not you.

That’s not the fucking point, you arrogant p.o.s. They WOULD IF THEY COULD. You’re still professing that cg artists should be every bit as restricted as practical artists. Despite my repeated reminders that supervisors and directors CONSTANTLY ask for unrealistic stuff. I would f’ing love to be there when you tell a supe that ‘no, I won’t do what you ask, because it’s not physically correct’.

So those guys building 2-story robots that walk, talk, emote, fight, transform, fly, and destroy skyscrapers, are having an easy time of it? The very idea that no one asks for anymore in cg than you can do in real life is unbelievably stupid.

That’s funny, because I had to “get creative” with lighting just to get something that looked NORMAL. A simple ‘off’ switch is ALL I needed to avoid wasting time experimenting with workarounds. Just like you get with raytracing, motion blur, dof, global illumination, etc. etc… you do realize you can turn those off, right??

#78

Really? Can you change the spread, color, or falloff of an IES light? Can you turn off shadows?

Now you’re putting title over content. What makes you think he has an art degree - that he says “well, ILM does it” all the time? Anyone who thinks “phyisically accurate” is more important than aesthetics, needs a goddamn art class. Our job is NOT to produce things that any schmuck could go out and photograph on his own. His imdb page is shorter than mine, so just stow this BS where the sun don’t shine. I fucking swear to god, the number of people who believe in the Emperor’s New Clothes just makes it embarrassing to be human sometimes.

Do they change the falloff? Do they have to worry about render times? This is ridiculous, you’re just repeating the same argument that cg lighters should have the same f’ing limits as real lighters, even though we have supervisors that CONSTANTLY ask for completely unrealistic things.

THEY DON’T HAVE TO USE DIFFERENT RENDERERS AND SHADERS PROGRAMMED BY A DOZEN DIFFERENT PEOPLE EITHER. They don’t have to use INACCURATE lighting like Interpolated GI, or cg lights. Unless you can somehow argue that all these renderers are in fact SIMULATORS, your argument is worthless. And until practical lights come an “invisible” option, then it’s also just plain wrong. It’s absurd to say “they have no limits” when cg lighting offers SO many more options.

Is there something about;

  • “I’m just tired of doing workarounds for things that don’t help me in the first place.”
  • “Who else has never gotten a single benefit from this ‘feature’, only extra work, extensive node networks and complicated hacks to get around?”
  • “I know the workarounds, I’m just tired of taking the extra time for no good reason.”
  • “Thanks but I applied the workaround a long time ago. I’m just sick of doing workarounds for a feature that takes control away the artist, and locks it.”

… that makes you think, that I think, that workarounds are not an option?

Gee thanks for repeating the same juvenile BULLSHIT that I just pointed out in my last post.

Please remember these words the next time your supervisor asks for something to be brighter, and then says “why is the reflection darker?” when you try to do what he asked.

And not ask for any improvements. Just do more work to get the same result, quietly.

That’s great - do you put “physically accurate” before aesthetics?

#79

Ok, fair enough, here’s my question.

What is it about:

  • “I’m just tired of doing workarounds for things that don’t help me in the first place.”
  • “Who else has never gotten a single benefit from this ‘feature’, only extra work, extensive node networks and complicated hacks to get around?”
  • “I know the workarounds, I’m just tired of taking the extra time for no good reason.”

and especially:

  • “Thanks but I applied the workaround a long time ago. I’m just sick of doing workarounds for a feature that takes control away the artist, and locks it.”

that makes people think I need help with the shader?

Well considering that people seem to think that the earth being round is “insane”, I’ll take insanity, thank you.

#80

Let it die guys, I feel like we’re in the max forums… :smiley:

#81

Yes, multi-million dollar pipeline of textured assets, VRay, and HDRs shot with a 5D.

I literally have no idea what we’re talking about anymore, and I’m sure you have no idea what we’re talking about, so until there’s a .ma file, I’ll just send along an example of how easy it is to make a non-conserving material…and I’m out.

You speak like this is a non-stop issue for you, so I don’t see why you can’t put together a sample file for us to look at. If it’s too uncommon an issue for you to find a file with problems, or be able to make one…why are we even having this discussion at all? You know there’s render passes too right? You can just crank up reflection (or anything) in comp. Render out multimattes and you can control it even more.

https://dl.dropboxusercontent.com/u/26845156/Terribly_Ugly_Shader.mb

Cheers.

#82

Terribly_Ugly_Shader.mb

This is why you people can never be trusted. Lies lies lies.

#83

@guccione, how I know that about him is because I work with him and I can vouch for both his knowledge and talent. And may I ask for you IMDb page? I’m also curious who I’m talking to and the name you are using on the forum, gives me little to go on and forces me to make assumptions.

#84

Making a lot of new friends I see, Guccione?

#85

You’ve “lit hundreds of shots in tv and features” all from home? Shoot your own hdr’s and paint/grade them?

Because locking features ‘on’ is STUPID. As I’ve pointed out, in not-so-many words, a dozen times now.

“And you know for a fact that this works with vray hair shaders? Or shall I dick around for another 2hrs to find out that it doesn’t work, just for the chance that you can continue to claim that only the most ‘physically accurate’ features should be allowed in 3d.”

I’m sure you have no idea what we’re talking about

That’s a bunch of crap.

The entire conversation so far;
“I’m sick of doing workarounds for a feature that can’t be switched off”

““I’m sick of doing workarounds for a feature that can’t be switched off””

“”“I’m sick of doing workarounds for a feature that can’t be switched off”""

“But we need this feature. Because I like to tell my supervisor that ‘No, I can’t do that, it’s not physically correct’ - since that’s more important than aesthetics. And because ILM uses it. Just do a workaround.”

That’s utterly ridiculous. Realism is one aspect used to create good visuals. Where it doesn’t help, you do not use it. Luminous white eyes are in almost every Pixar character, and self-illumination is included in most diffuse or all-purpose shaders. How “physically accurate” is that?

Sure, that’s because they’re selling it as a photoreal renderer. They may also like the way it looks. But it’s pretty silly to act like ‘physically accurate’ is their ultimate concern when they still use shadow maps, point clouds/brick maps, and reflection maps, isn’t it? (and please don’t try to claim again that shaders have to be physically accurate, but not lighting; that’s just weak backpedalling). Put a frame of Monster’s U next to a frame of Corpse Bride, then ask yourself how much they really care about realism.

#86

I see no reason why a shader shouldn’t allow energy conservation to be turned off, under perhaps an ‘advanced’ section, with a warning that things may break somewhere.

Having been on the Maxwell testing team for many years and also testing/following the development of other renderers, I totally understand why energy conservation has become the norm. People in this thread are already WAY ahead of many many users’ understanding of lighting and shading by even knowing what energy conservation is. There are an enormous amount of people out there who will push and pull shading attributes around without understanding them and then complain on forums or to the renderer devs that they’re getting artifacts like NaN/divide by zero, black pixel, super white pixel, unrealistic GI results or noise in their renders that won’t clear up.

In the end the renderer is doing math and the more you bend the math the more likely things are to get out of control somewhere and return a problem, either visually or in the form of a crash or excessively long render time.

By imposing some restrictions like energy conservation you are:

  1. Preventing users from breaking the renderer.
  2. Helping less experienced artists to achieve pleasing results.
  3. Simplifying the development of the renderer. You don’t need to start having GI, motion blur, sampling etc algorithms that can handle unexpected shader results.
  4. Starting from a more physically plausible baseline.

To a certain degree it is catering to the lowest common denominator, artists without technical understanding. It just so happens that it also approaches reality which often tends to be the desired outcome anyway.

But sure, have the option to turn it off. I see nothing wrong with that.

#87

People who constantly misrepresent you are not looking to be friends -

#88

You can ask…

( sorry, one of my favorite lines from galactica, always wanted to say it :slight_smile: )

I’d rather the discussion not be judged by title or some contest, but by content. Like how many times I’ve had to repeat myself, and how many times I’ve made points that are completely ignored. Whatever assumptions you’re making are probably outside the scope of the discussion, trying to judge my motivation or something? Anyway, none of that should be necessary.

#89

Nothing is locked.

You can disregard energy conservation in two seconds via a VRayBlendMtl in Additive Mode.

The workflow for non-energy conserving shaders is a node heavy setup of fresnel blending against the diffuse component, the reflections, another set of blending if you want refractions, and even more if you want SSS, etc…all of which will never compute as fast as compiled code dedicated to the task.

Considering 99.99% of the time you want energy conservation, and considering it’s by far the more elaborate setup to have to recreate if it’s missing…it should absolutely be the default, which it universally is.

Lastly, are you NOT outputting render passes? They exist so that if you want more reflections, you just boost the reflections in comp without having to worry about what was actually rendered…and multimattes to further isolate selections.

However, if you couldn’t get a VRayHairMtl3 to appear like blonde hair, you were definitely missing something in your settings.

Our “multi million dollar pipeline” you keep talking about is essentially no different than what people are doing at home. Most of our software is basically the same as off the shelf versions, and it’s really the data management, publishing, and all of that stuff where the TD side of things take over and where the money goes.

#90

Hi Guccione, may I ask which version of V-Ray are you using?
It seems all the points you raise with the V-Ray IES lights are already there, at least in the V-Ray for Maya version 2.45.01. Maybe that could be the issue? I’m not sure. :slight_smile:

Yes, by changing the IES file -I guess if you want full control of a CG light, it would be best to use a spotlight, obviously as IES are measured profiles of lights - that is their sole intention.
http://www.photometricviewer.com/

That is a really cool program to quickly toggle through the different profiles.

Yes, either with temperature (kelvins) or whatever color you would like, pink, purple, file texture using the color mappable attribute…

Yes, with the cutoff threshold, I suppose one could also map something to the intensity possibly like a ramp.

Yes, as well as individual and accurate controls for Diffuse, Specular and Area Speculars. In V-Ray 2.45 there is also a parameter to change shadow color or use soft shadows.