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The Realism Challenge - Biased VS Unbiased Showdown
Posted: 17 February 2013 07:20 PM   [ Ignore ]   [ # 76 ]
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cwichura - 17 February 2013 06:14 PM

As an aside, what render engine does Carrara use under the hood?

It has it’s own render engine.

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Posted: 17 February 2013 08:06 PM   [ Ignore ]   [ # 77 ]
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Bryce 7 Pro

IBL lighting supplied by an HDR backdrop, three radial fill lights, render time just over an hour.

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Posted: 17 February 2013 08:58 PM   [ Ignore ]   [ # 78 ]
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TheSavage64 - 17 February 2013 08:06 PM

Bryce 7 Pro

IBL lighting supplied by an HDR backdrop, three radial fill lights, render time just over an hour.


Nice bike! I’m glad to see some nice Bryce renders.

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Posted: 17 February 2013 09:18 PM   [ Ignore ]   [ # 79 ]
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Here’s a couple of DS renders…

The crayfish uses a ShaderMixer spotlight that accepts gels…the ‘bubbles’ are a plane with transmap, in front of the camera and the ‘fog’ is a ShaderMixer camera.

The fishbowl is a custom glass shader.

The goblets use a couple of ‘normal’ spots, the custom glass shader and self made reflection maps…the reflection maps were made from spheres, with the gold metal setting, rendered in Luxrender.

The Tucker is an UberEvironment along with a couple of spots for ‘fill’ and specularity.  The shaders on the car are the SuperShine freebies. (put up the wrong Tucker image, at first…)

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Posted: 17 February 2013 11:57 PM   [ Ignore ]   [ # 80 ]
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Created and rendered in Carrara 8 whilst also reading my ‘New Dawn’ Magazine.. and the girls reckon I can’t multi-task! smile

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Posted: 18 February 2013 01:16 AM   [ Ignore ]   [ # 81 ]
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This thread will produce some nice images, but it will not get to the root of the issue. The real question is: “what are the benefits of unbiased rendering?”

To get anywhere, you need to specify a few things. First of all, forget about humans, they aren’t going to look realistic in any software unless you know as much about human facial expressions as you do shaders and lights. Humans are too distracting.

What you need to do is to look at specific technical things unbiased render engines can do well and see if you can recreate that in Bryce, Carrara, or Daz Studio.

Technical issues like prismatic banding of diamonds is a good test to demonstrate the benefits of unbiased rendering and why it is often so much superior to biased rendering. Again, forget humans, lets see how many Carrara users can render diamonds as well as Luxrender.

Diamonds, show me your diamonds if you dare!!!!!!!!

In order to get anywhere you need to have a good grasp of what “bias” is in the first place and why Carrara, Bryce and Daz studio are biased engines. Bias is introduced by shortcuts. Not all shortcuts are obvious to the layman viewer, but they are still there. Carrara is very good at hiding most of its biases, but they are still there. some scenarios demonstrate biases more than others, so a standardized scene is the way to go.

It is dangerous in my view to try to determine biased or unbiased status based on the final look of an image. Final results have nothing to do with it. It has to do with the way the work was approached mathematically, period. Results are meaningless.

Now I am a firm believer that the user is the final piece of the puzzle, but that isnt to say it is a fair fight. Many of us who believe the user makes the biggest difference are likely to have our feelings hurt in this thread, because unbiased render engines in the right hands can and will outperform even the most gifted biased render artist. Honestly, this is not a fair fight.

Unbiased rendering isnt about artistry, its about pure mathematics. This thread is not addressing that point. Artistry is good at creating distractions, forcing the viewer to pay more attention to the things you want them to focus on in hopes they might not notice other things. Unbiased rendering one need not worry about that.

In time, all rendering will likely be unbiased. Just the way it goes.

The secret to realism is one word….Interaction. The more the given elements of a render can interact with one another by casting shadows onto one another, reflecting colors onto one another, transmitting one another…these interactive effects create a world that is believable. Placing point lights/ area lights etc to fill in surface bounces that arent actually happening within the render engine can create very good looking renders, but they still arent physically accurate, so the believability doesnt really matter..

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Posted: 18 February 2013 02:25 AM   [ Ignore ]   [ # 82 ]
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...well said, which is why I gave up on trying to push for realism years ago.

Even with IBL UberEnvironment and other lighting/surface plugins. Biased render engines like 3Delight for Daz Studio and Poser’s Firefly can only come “so close”.

Before Lux/Reality, one had to invest a hefty amount into a pro grade application and/or standalone render engine (as well as the hardware to support it) to approach any sense of realism. At the time this was just not in the budgets of most hobbyist 3D artists.

Reality/Lux has changed that, but it still takes a lot of time and effort, tweaking, rendering tweaking and rendering again to be able to use it to it’s full potential. 

Personally I would rather spend more time on refining what is in the scene (hence the years I put into developing my Leela character for example) instead of constantly messing around with light and surface settings to attempt to achieve “photo perfection”.  I’m from that school that would rather have the subject and composition say what I want. Granted, my pics may not have that certain “pop” (as Waldemar puts it), but I’m OK with that because I know the limits of the software I’m dealing with and am willing to work within them.

The pic I posted a page or so back was basically a “raw” 3Delight render using only the standard Daz lights and no special surface or lighting effects. As I mentioned, I didn’t even use ray tracing. In spite of this, I think it came out pretty good for what was involved in its creation.

I guess for me the benefit of a biased render engine is that it is more simple and straightforward to use leaving me more time to devote to the scene I am creating.

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Posted: 18 February 2013 03:00 AM   [ Ignore ]   [ # 83 ]
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Rashad Carter - 18 February 2013 01:16 AM

Unbiased rendering isnt about artistry, its about pure mathematics. This thread is not addressing that point. Artistry is good at creating distractions, forcing the viewer to pay more attention to the things you want them to focus on in hopes they might not notice other things. Unbiased rendering one need not worry about that.

In time, all rendering will likely be unbiased. Just the way it goes.

Even some so-called ‘unbiased’ renderers have had bias included as part of their package somewhere. The reasoning is quite simple. Some parts of an image don’t actually benefit visibly from the unbiased nature of the renderer, while others require a lot more focus. Lux included bias in the form of a refining brush allowing the user to select parts of the image to focus on, while reducing the focus in other parts.

It’s important to note that the only major difference between a biased renderer and an unbiased one, is that a biased render tries to avoid making unnecessary calculations, while a biased renderer will make them regardless. Different engines have their own way to go about this, but essentially it boils down to that one fact. Leave a biased render long enough and chances are good you’ll have something somewhat realistic at the end of it. Does that mean you can never reproduce that effect with a biased render engine? No, it simply means that it the unbiased engine made more calculations to get to that point.

Fully unbiased rendering suffers from a serious incurable problem, which is why it won’t replace biased rendering completely. The problem is noise, and it can be anything from a slight speckle to a cascade of white dots. These can further develop into fireflies the longer the engine rolls on and in some cases require thousands of samples to clear up. Worst case scenario is that they never do.

It’s worth noting that Pixar uses PRman (Photo-Realistic RenderMan) which uses a lot of bias to keep render times down yet, as I’m sure people have noticed, can produce absolutely amazing results. The onus here is really on the artist to do the best they can with the engine they choose, rather than argue that one type of engine will always produce better results.

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Posted: 18 February 2013 03:12 AM   [ Ignore ]   [ # 84 ]
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Some good points made, and some excellent renders posted.

I particularly have to mention:

Hiro Protagonist - Fantastic render of the mini.  Definitely nice to finally see some Lux renders in the thread.  I’m waiting for Reality for Poser to be released so that I can have a go there myself.

TheSavage64 - Great render of the Harley.  Bryce was one of my favourite programs, but there was too much of a gap between upgrades and I switched to Vue.  However, I do still have a soft spot for Bryce and as you’ve demonstrated, in the right hands it is still capable of some fantastic effects.

Stezza - The steamroller pic is brilliant.  Awesome job there.

Rashad Carter - 18 February 2013 01:16 AM

...Final results have nothing to do with it….


You do make some good points elsewhere in your post, but unless I’m misunderstanding the context of this part, then I’d have to disagree here.

Surely the only important thing is the end result?  Whether someone is a hobbyist or professional, the end result is what matters.  Outside of the 3D community, where we like to share techniques, no one cares which piece of software or render engine you used as long as the end result is fit for purpose.

 

As several people have stated here, it is more the person using it than the software / render engine in most cases.  The three images I mentioned above are very impressive because I know that cars should be easy to make realistic renders of (compared to human faces for example), but I know from personal experience that it is a lot more difficult than you might at first think.

I have seen some renders done with Poser 4 that I still can’t match for “realism”.  On the other hand, I’ve also seen renders done in Lux that might as well have been done in Poser 3.

It is interesting though to actually see the results of different render engines together in a thread like this - I hope people keep posting.

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Posted: 18 February 2013 05:03 AM   [ Ignore ]   [ # 85 ]
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Rashad Carter - 18 February 2013 01:16 AM

First of all, forget about humans…

I’ve been saying that for YEARS!!

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Posted: 18 February 2013 05:05 AM   [ Ignore ]   [ # 86 ]
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Gemstones! Okay, so they’re chaos emeralds but I’ve used the correct IOR for their respective materials. They are, in no particular order, Topaz, Diamond, Emerald, Sapphire, Turquoise, Ruby and Amethyst. Oddly enough the sapphire came out almost purple.

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Posted: 18 February 2013 05:49 AM   [ Ignore ]   [ # 87 ]
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Biased vs. unbiased isn’t the only distinction, either.  Lux is also a spectral renderer rather than an RGB renderer, which helps it render things like caustics and metal more realistically.  (SLG is RGB, though, not spectral, and that is one of the things that contributes to its speed on GPUs.)

And while I didn’t say it in my original reply, I also believe that the renderer is just a tool, and it’s the user that really determines the final results.  Watching dA, I see fantastically realistic renders done with both 3Delight and Firefly, and some truly dreadful and un-realistic looking renders done with LuxRender simply because the user doesn’t know how to set up decent material settings for LuxRender.

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Posted: 18 February 2013 06:31 AM   [ Ignore ]   [ # 88 ]
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HeraldOfFire - 18 February 2013 05:05 AM

Gemstones! Okay, so they’re chaos emeralds but I’ve used the correct IOR for their respective materials.

Thank-you HeraldOfFire and Rashad Carter for bringing up the subject of the technical differences between the render engine types. And gemstones in particular!

Here is one of my newest Carrara renders. I’ve scrapped this current line of renders in order to start again and pay much more attention to the background room. The center piece is the texture that I called “crushed sapphires” on V4.

It is high-rez texture and normal maps. But it does lack that gemstone sparkle that show up so beautifully in HeraldOfFire’s display. Do I need geometry to acheive that effect?

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Posted: 18 February 2013 06:41 AM   [ Ignore ]   [ # 89 ]
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Posted: 18 February 2013 07:45 AM   [ Ignore ]   [ # 90 ]
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I’ve only recently come back to rendering after a long break.  I saw the price on DS 4.5 Pro and said “Why not?”  grin  The last Studio I used was 2.3!  I’ve got plenty of content from 4-5 years ago so that’s what I’ll use.

Vanessa for V4 in DAZ 4.5

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