Iray and Reality Compared
K T Ong
Posts: 486
Hi, fellas. Been playing a bit with both Iray and Reality (Version 4), and I thought I'd share what I think of the two. From what I understand, they both attempt to simulate real physical lighting in their renders. Yet there appear to be significant differences in the sort of results they can produce.
First, when it comes to rendering human skin, I think I'd have to give the credits to Reality. It renders really gorgeous skin, complete with SSS and all, even on standalone figures like the flower-winged demon below (to which you cannot apply anything from M4, V4, G1, G2M, G2F etc if I'm not mistaken, since it's a standalone figure). And it's very easy to make the skin look wet or greasy, too. As far as I can tell you can't achieve that (yet?) in Iray -- at least not without a great deal of experimenting and tedious tweaking, which being a mere hobbyist I'm not prepared to spend much time on!
On the other hand, it is Iray that emerges the champion when it comes to things like rendering the surfaces of environmental and architectural props. Those bumps and crevasses on the surfaces are readily and beautifully rendered with hardly any need for any tweaking. It's also very easy to make them look shiny and reflective. This is what I found with the Iray render below showing two guys. I have to say I was absolutely impressed with the look of the floor tiles. Haven't been able to reproduce that in Reality no matter how I tried.
My final verdict is that each of the two renderers has its own strengths and weaknesses. Perhaps in due course both Iray and Reality will develop to the point where both can enable one to handle human skin and the surfaces of props with equal ease and effectiveness. But for now as far as I can tell, one is good mainly at this while the other is mainly good at that. What are your thoughts? Do you think I've missed out on anything? :)
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Comments
Nice renders!
Reality is a plugin not the render engine. That would be Lux :)
I played around with both Iray and Lux and I like Iray better. Its fast and can produce realistic looking skin just as well as Lux. Look up MEC4D's renders in the gallery and you'll see.
Thank you. ;-)
I know that Reality uses Luxrender. Mec4D's renders of human figures are admittedly great but I think I've yet to see a standalone figure being rendered in Iray as nicely as Reality can render the Nybras demon. (I won't count the Dragon 3 figure since it has scales rather than skin. ;-) ) Well, to each his/her own. (Shrugs.)
You also need to keep in mind that Iray has been around in DS for about 5 minutes compared to Reality/Luxus's rather long beard. The lighting used is also very important to the final results.
Cool renders too btw.
I personally wouldn't compare the two (actually 3) as they are incredibly efficient at what they do through different methods. Reality in my experience acts as sort of a bridge to Lux and I have enjoyed very much playing with it. Reality sort of has things laid out for you rather than have us manually build materials completely from scratch either from pre-built shaders or original custom made ones, which is basically what most render engines themselves make us do, eg Iray, Octane, Vray, MentalRay etc. Reality has the shaders built already, they are very well done but Ive found it limiting as It doesn't (or didn't in older versions rather) offer much option for me to completely make my own with all the bells and whistles. Eg it has skin, glass, metals etc already layed out with only preset settings to tweak to make the material how you want, but If I made my own shader in say MentalRay I would be able to use and modify all manner of possible surface settings I choose to have in that shader to make what ever material I desire.
But again I cannot personally compare Reality to Iray, because Reality ISNT a render engine, I think its an excellent plug-in to make use of Lux, I haven't used Lux alone, but am assuming its much like all the other engines on its own. I like the freedom of Iray, Octane and MR etc, they can all do the same things, so long as you know how, speeds vary between them, but it depends on the methods you do things and how they utilize GPU rendering, as well as how much our hardware complies to their requirements.
Excellent Renders KT! As far as what you mentioned on skin and lighting, imo it really depends on how well you know Iray and Reality (And other apps/engines) as to how easy or complicated it is to do those things :)
The only fair comparison would involve identical models, composition and lighting. You would have to tweak the shaders probably. I bet they would be very similar in results except for render times with Iray being faster with an NVIDIA card... probably close with CPU rendering, though maybe faster with the new version of Reality/LuxRender Paolo has been talking about.
I bought reality 2 way back when, but as a compulsive material tweaker It just didn't work at all in my workflow. I ended up using Cycles and now mostly Iray. There was also the fact that with Reality every tweak to the materials you had to re-export the mesh, I don't know if that has changed with newer versions or not but when you're doing 50+ 10 iteration test renders the minute it takes to load the meshes and textures adds up.
What reality is good at is setting up good basic shaders for the end user, the cycles exporter doesn't do that at all, and Iray is very dependent on what 3delight shader was used. Daz and Nvidia did a great job on the automatic AoA shader conversions, but, particularly when it comes to skin, other shader conversions are spotty.
Reality also has the simplest interface. Once again, If you are a busybody like be and want to control and tweak everything it feels limiting, but it is much less daunting to look at than the Iray ubershader, let alone cycles node system. I love it, but I understand I am a bit of an odd duck when it comes to my feelings towards blender's ease of use, but when it comes to control it is the best. What other render engine can you mix three different bump maps and have them tile at different rates and mix uv maps? and it's easy! I swear!
At some point I was going to do a render engine comparison with the different render engines (pre iray so reality, cycles, and 3delight) but the Reality one was taking too long so I got bored and did other things
There is not really comparison between both as both are unbiased , the only difference here are the light setup and materials you create so the comparison is actually of your skills with both programs Iray and Luxrender or Octane as Reality is just exporter
to have a true comparison you will have to use the same PBR materials and the same HDRI maps or light setup.
I made comparison a time ago with the same materials and there was slightly difference , however each program offer different skin solutions shaders so that is all about . It is like comparing milk from 2 different cows, the process is the same and the difference in taste would depends of the food you trow her in the stomach LOL
Well, that Cath, has got to be the best way of describing the differences between the 3 physics based renderers commonly used from DS...
Translated to : Simple is beautiful LOL
Well, that Cath, has got to be the best way of describing the differences between the 3 physics based renderers commonly used from DS...
It is like comparing the taste the milk from a cow and from a sheep, the two animals having given different diets, living in different geographical locations and the milks processed in different ways. Not even wrong.
There is one rule for physics based renderers , shooting photons with a light speed into the surface and bounce it back into your eyes ;) , what is different in each program are the materials translations , put a metal sphere in each program use the same HDRI maps and you will see no difference , so the comparison here would be how good the materials response to the light , it is simple ... it is not rendering issue here but material setting , how many of the comparison images showing the same material setting ? zero , nada not to forget to mention that each program have different calibration for PBR , I like all of them, but I choice the fasted one at this moment
It is like comparing the taste the milk from a cow and from a sheep, the two animals having given different diets, living in different geographical locations and the milks processed in different ways. Not even wrong.
Thanks for sharing your thoughts, fellas, and no less for your kind comments on my renders. :-)
I guess MEC4D and latego put it best: it's like comparing the milk of two different cows or two types of farm animals. %-P
I still like 3Delight very much and use it very often, by the way. There are more than a few nice things that can be used with 3Delight but apparently neither with Reality or Iray, such as LAMH or Vascularity HD for G1/G2. (Or can they?...)
Totally agree .. we just got more Tools for our Art work and nothing bad about that !
Luxrender has one big advantage, you can adjust the exposure while the render is in progress. I assume it must be doing the render in high dynamic range and then applying the tone mapping to get the image. This means after a long render you can fine tune the tone mapping to get the look you want. In Iray you would have to do the entire render again.
I don't know if it would be possible to add this functionality to Iray, it would depend on whether the image data it is working on covers the entire brightness range or has been tone mapped at the beginning.
You can adjust during the renderw ith Iray. There's slider to the left in the Render window that opens the settings that can be used during render.
EDIT: Even if your render has already finished, if you change any settings there you can resume the render again with the new settings.
I was going to say, no comparison, it comes down to the person using them. But I see more eloquent explanations of that.
The real comparison for me would be when I see a true hair system and atmosphere/volumetric cloud system. The first one to get PAs or DAZ 3D to give us these and does so competently will win me over. I haven't been able to use LAMH since that system was introduced, what a nightmare.
Thank you for pointing that out.
I'm experimenting with this now. It doesn't seem to work quite as well as Luxrender. I found that adjusting the exposure during a render often makes the image more grainy, and after the last change I did the progress bar jumped backwards from 90% to 20%.
Thank you for pointing that out.
I'm experimenting with this now. It doesn't seem to work quite as well as Luxrender. I found that adjusting the exposure during a render often makes the image more grainy, and after the last change I did the progress bar jumped backwards from 90% to 20%.
It was pointed out in another thread by one of the DAZ people (Spookie?) that NVIDIA introduced a bug in the latest version of Iray that causes this issue. Some changes in tone mapping cause the render to restart. However this is not the intended behavior. We will have to wait for a fix from Nvidia.
TD
I like both.
Iray is much faster but Lux allows for more adjustments as the image renders which I absolutely LOVE!
LuxRender's CPU rendering just got faster, Paolo did a comparison test between current Luxrender version and the new one and played it on Youtube and he showed a 10 to 1 (average) speed increase.
https://www.youtube.com/watch?v=b6fyJQOzfvU
with Iray I can adjust tone mapping after render is done in the viewport too in real time since tone mapping is post production
or in new window but usually it resume the render
That is correct I noticed that in the open render window , before it worked without issues
It was pointed out in another thread by one of the DAZ people (Spookie?) that NVIDIA introduced a bug in the latest version of Iray that causes this issue. Some changes in tone mapping cause the render to restart. However this is not the intended behavior. We will have to wait for a fix from Nvidia.
TD
Yeah I heard there was an update coming soon with significant speed increase! Can´t wait for it to come out : )
Also the particles/curves/volumes will need to be an Nvidia thing too...Iray itself needs to support them fully before Studio can. I'm not sure of the exact state of support for all of that in Iray, just that it isn't any where near the level of 3DL.
I've used both render engines, my opinion both are fabulous engines. One is not necessarily faster or better then the other. It all comes down to computer power, 3D artist preferance, scene creation. Reality/Lux has a very easy/friendly user interface, I learned alot using Reality/Lux, transferred knowledge over to IRay. Attempting to create human realism I prefer Reality/Lux, anything else I enjoy using IRay.
Truth is, if anyone desires speed, one should invest in improving computer power. Computer power = speed. I noticed a major difference between dual core vs eight core. Four video cards, work much faster then one.
Not exactly , Maya hair can render with Iray and many other stuff so it is not just Nvidia thing .. Daz need to improve DS and I hope really for finally dynamic cloth .. soft bullets can be done so easy too , I saw simulation of that by one of my friend programmer
That's because, Iray only supports some curves...it's been a few weeks since I looked all that stuff up. As it is right now, it's the wrong kind for Studio (Studio's curve based hairs, short of the upcoming update for LAMH, only support one kind of curve anyway...), so with hair, at least, it's both.
It's the same with most other renderers, Luxrender's curve/particle support is one of the things being expanded...
It is 3Delight that support hair shader not DS , Maya also support 3Delight hair shader rendered using Monte-Carlo simulation like LAMH or Garibaldi in DS . What we need is a procedural Iray shader that can generates Iray curve primitives , it is all possible only someone need to do that :)
That's because, Iray only supports some curves...it's been a few weeks since I looked all that stuff up. As it is right now, it's the wrong kind for Studio (Studio's curve based hairs, short of the upcoming update for LAMH, only support one kind of curve anyway...), so with hair, at least, it's both.
It's the same with most other renderers, Luxrender's curve/particle support is one of the things being expanded...
Kendall posted in another thread that LAMH is getting closer to a version for Iray..... :D I can't wait!
That is awesome !