'Energy Conservation' in Vray (and others)

[guccione]

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

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.

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.

To me as an artist, my dream software package would give me the most physically accurate surface model

“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.

that can be computed in a reasonable time

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

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.

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.

This discussion isn’t about lighting though, it’s about shaders

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 must be physical plausibility.

Absolutely wrong.

There isn’t some conspiracy going on between studios and rendering packages.

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.

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.

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

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.

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

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.

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?

[CristianCamaroschi]

@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.

[kweechy]

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.

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.

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.

[Stellios]

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.

[guccione]

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.

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?

The renderer isn’t enforcing energy conservation, it’s just the shader. Add as many as you want together; there is nothing stopping you.

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.

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.

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 great, but they can’t.

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’.

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.

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.

Get creative with your lighting, don’t get creative with completely arbitrary energy return on your shaders.

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??

[guccione]

@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.

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

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.

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.

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.

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.

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.

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.

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.

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?

There IS no conspiracy,

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

it is jut the way the industry is going…for the better.

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.

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

studied art for a big portion of my years.

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

[guccione]

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.

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?

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

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

[JasonA]

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

[kweechy]

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.

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.

[obz]

so until there’s a .ma file,

Terribly_Ugly_Shader.mb

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

[CristianCamaroschi]

@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.

[InfernalDarkness]

Making a lot of new friends I see, Guccione?

[guccione]

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

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

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?

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

I’ll just send along an example of how easy it is to make a non-conserving material…and I’m out.

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.

“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.”

• “Does everyone here think that realism = aesthetics?”

Yes.

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?

That’s why even cartoon CGI features use physical shading models. Renderman 19 is entirely based around a Burley/GTR/Schlick/Smyth microfacet model.

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.

[Jozvex]

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.

[guccione]

Making a lot of new friends I see, Guccione?

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

[guccione]

@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?

You can ask…

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

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.

[kweechy]

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.

[Hamburger]

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.

Can you change the spread (IES)?

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.

color

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

falloff of an IES light? Can you turn off shadows?

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

Can you turn off shadows?

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.

[A-OC]

This is my interpretation of what this troll wants:

1. “I want my VRayMaterial to have a checkbox just like mantra surface, where you can turn off energy conservation, or at least to behave like Arnold’s aiStandard where I can take care of energy conservation by my self”

2. “I want the VRayHairMaterial to produce beautiful blond hair”

My answers would be:

No can’t do, just use the other suggestions like vray blend mtl, passes and multi mattes.

I can’t understand why this seems so hard, since color correcting our shots is as important as look dev. And as others have said, you’ll want energy conservation 99.9816 % of the time, unless you’re doing FX like lightnings or thelike.

Beautiful blond hair is really hard to achieve. Best results I’ve got in the least render time, with the least GI artifacts have been with arnold. So try that.

Q. for the troll: Are you absolutely sure you are properly using linear workflow ?

[guccione]

Nothing is locked.

Then why do you have to work - around it, genius?

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

“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.”

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

I see, you don’t know if it works. I should experiment for (and waste) another hour to find out, because you like inflexibilty.

Considering 99.99% of the time I want energy conservation to be checked on even when I need flexibilty, 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.

^Fixed it for ya

You still seem to be arguing that I don’t want the feature to be offered, when I keep saying that I want it to be an OPTION, just like EVERY OTHER FEATURE.

No energy conservation - oh how horribly fake looking.
https://www.youtube.com/watch?v=6Kt3WR0J5Vk
https://www.youtube.com/watch?v=YeXDSYF2xDk

Half of these jet shots have energy conservation (vray), half don’t(lightwave). Tell us which is which.
https://www.youtube.com/watch?v=_sdJPn_PRWg

Energy conservation is a MINOR improvement, that does not justify workarounds.

Lastly, are you NOT outputting render passes?

Yea I’m doing all that. Do you think it’s a good idea to send renders to the compers that have the wrong colors?? And just hope they get it right… instead of actually spending time making the image better? All because a feature is locked, and assumes that every single thing that comes before it is 100% ‘physically accurate’. I don’t.

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.

So it’s ‘only’ a six-figure pipeline? Does every little boutique have that much to throw around? The point is, you have far less to deal with than someone at home or at a small studio, so stop telling everyone how ‘easy’ it is to do yet another workaround.