Glass with Soda - Cycles vsOctane

[ChrisH]

(Highres [9mb, 3188x2400])

Decided to test Cycles against Octane, so created this simple scene.
The setup is almost exactly the same (I could’ve done more but…). The main differences is the colors of the light (Blackbody in Octane, color in Cycles [let’s hope for bb in the future]).
I tried to keep everything else the same, but it’s not easy, Example, for glass in Octane (specular) you have IoR, reflection and roughness. In Cycles you have roughness and “fresnel” (basically IoR + Reflection). So in Cycles you need to choose a value that looks the best, instead of choosing a value you know is physically correct.
I also had a problem with DoF in Cycles (with a lens radius of just 0.01, the DoF was way to shallow), which is why it’s all in focus in the Cycles-render.
(Focal-length in Blender 80mm, FoV in Octane: 14.7)
Also notable that Cycles seems to give renders with higher saturation (as “default”).

But Cycles is still Alpha, and I do believe it can be really great (it’s already pretty good).

My final thoughts on these two renders is:
The Octane-render is more realistic, but the Cycles-render is a bit more artistically appealing. (I think the reflection in the “table” looks much better in Cycles, but with this light-setup it’s more realistic in Octane [I actually tried to reproduce it in Octane, but couldn’t]).

1024 passes in Cycles
6400 samples / pixels in Octane

That was my thoughts, what do you think?

[JoseConseco]

I like octane more. Also wood reflections seems to be not existing in cycles render.
What were the render times? Is octane much faster?
Also what is the thing ‘black body’?

[agentmilo]

Octane looks pretty realistic while Cycles yells ‘CG!’ at me. The blackbody makes a lot of difference here. The underside of the glass in the Cycles render looks weird, almost as if its an exact mirror with some color variation. I agree that the reflection on the table in the Cycles render looks more appealing.

But I think its only fair if you avoid the Blackbody spectrum in Octane and instead use a point based light, as seen in Cycles. Its only then can we really compare the difference. Here the Blackbody pushes alot in Octane’s favor.

Nice comparison btw.

[Jakerlund]

Hi!

First i have to say… i’m still quite a beginner in 3D so my inputs are based on what i’ve learned so far.
I did a little test with my old Mac Pro (2006) which obviously takes forever to render stuff on.
I have no experience with Luxrender or Cycles so didn’t expect any result worth sharing really, but i was quite surprised how nice the Luxrender pic looked. :eek:

After have seen J.Wiliamson’s Luxrender/Liquid-filled Glass tutorial i realized why my liquid looked strange, now i know how it should be done
I let Luxrender cook 10 hours over night (the picture has a little noise, but that was actually added in PS to get a less ultra clean look).
Then i tried render the same scene in Cycles, i applied what i thought was glass and liquid like materials and let it render for 4 hours/400 pass.
Ok… this isn’t a Lux vs Cycles test… it’s just a test, if i had used the right materials and let it cook for the same time as Lux i’m sure it would have looked a lot better.

I think Cycles in the future and in a modern computer and used by someone who actually knows what he’s doing will be fantastic, Luxrender is already stunning.
The future for good renders in Blender is looking very good.

@ChrisH
It would be nice to see your scene rendered in Luxrender!

[Michael_W]

Jakerlund, try turning the “roughness” of the glass down in teh cycles render!

Chrish, I’m curious how you set up the lighting in octane and cycles…

[namekuseijin]

lame comparisons, no render times, not same settings and materials. Also, Cycles is not supposed to be a completely realistic and unbiased renderer. It’s got full GI, caustics and physics based materials and that is awesome enough.

[shteeve]

I think the biggest barrier at this point is the difference in material and scene setup. A lot of these comparisons are apples to oranges, wherein in reflective/refractive properties seem to be quite varied between the renders. That said, cycles materials aren’t very clear for setting properties like IOR etc, so the problems are less with the render quality itself and more with the ease of user control/documentation.

I don’t know very much about how to leverage material nodes in cycles, so often i’m just playing around till I get something desirable. But such is to be expected from alpha software!

This was just a super quick test to see i could make some half decent looking glass. most things in the scene are super rough, and i’ve only let it render for about 10 or so minutes since i have to head out the door, but I thought i’d share anyway!

Attachments

[ChrisH]

Thank you for your comments.

@JoseConseco: The wood-material is just a glossy material (GGX, Rough:0.075, Fresnel:.960). To me it seems like light sources doesn’t get reflected in Cycles…
I’d say that Octane is much faster, at least on my system. I haven’t managed to get CUDA working with Cycles (not that I’ve spent much time on it), so it runs on the CPU (AMD Phenom II X6, 3.2GHz), whilst Octane runs on the GPU (Nvidia GeForce GTX 460, 1GB, 675MHz, 336 CUDA cores).

I should’ve written down the render times, but I didn’t. Wouldn’t it be nice if the render engines store that info in the meta-data of the images!? :?D

You can read about Black body on Wikipedia, but in short (and what’s most interesting from a 3D aspect) it’s a way to define physically correct light sources using real world data. You define the color temperature as degrees Kelvin. Examples: 6500K is pure white light, fluorescent lamps has a color temp. about 4500K and a normal light bulb has about 2000K. (The “warmer” light [sunsets etc] the lower the temperature and vice versa).
So working with black body gives you more realistic lighting and is natural to use if you’re used to irl lighting and photography.

@agentmilo: What do you mean by “Point based light”? I re-rendered it in Octane, with texture emission and RGB spectrum. But it’s a pain in set ups like this. It’s extremely “efficient”, so besides being waaay to bright with “normal power”, it results in white light, if you don’t turn the power to a minimum and/or use a color with high saturation.

[ChrisH]

Jakerlund: Hej, Hallå! :?D
Your renders looks pretty good, I agree with Michael W, in that you need to turn down the roughness. You also need to turn down the reflections (especially in the lux one), the surface looks more like metal than water. :?D
I’ll maybe try to render it lux later. :?)

Michael W: See below for the setup (there’s also a blend for Cycles).
What do you want to know more?
I was lazy and pulled in the lights from Live DB, 10000K to the left, 3500K to the right, 8000K from behind.

namekuseijin: Ookeey… :rolleyes: First of, I never claimed that this was complete comparison. I was playing around with Cycles and doing some more stuff and just decided to try to render the same scene in both renders, and then I posted it here, mostly for fun. And my “review” (which isn’t a review) is just me and my thoughts/ramblings.
Even though Octane and Cycles isn’t completely comparable, it can still be interesting to compare them. And Cycles might not be meant to give true realistic renders, it can still get pretty close (and closer than BI).
I tried to make the settings and materials so identical I could, it’s hard as they’re two different systems, with different properties etc. As for the light materials, that might been a mistake but not a big one…
Also note, I’m not trying to trash Cycles. I love Cycles and think it’s a great addition to Blender (and I’m going to use it, if not for full renders, I’ll be using it to set up meshlights etc).

Some final thoughts:
The reflections of the lights in Cycles acts a bit weird. The light to the left doesn’t get reflected in the glass, even though it is slightly visible when the rendering starts, it then “dissolves” and disappears.
The reflection at the bottom seems a bit too much in Cycles, but it’s not far from irl (I have the glass I modelled besides me to compare with). There’s almost to little reflection at the very bottom in Octane.
One thing that bugs me a little bit is my logo at the bottom of the glass, it’s a bumpmap/displacement. Through the liquid, it doesn’t look transparent, it almost looks like there’s a sticker or something like that (I guess it can be blamed on “the unrealistic nature of Cycles”, but still…)

I’m re-rendering them (without black bodies in Octane), leaving them to cook over night (will write down the render time)

Setup:

http://chris.hindefjord.se/Blandat/GlassLiq_Cycles.blend

[Remade]

hi ChrishH,

in cycles Fresnel is related to IOR mathematically so it can be setup accurately (i think Fresnel = 1-(1/IOR) ) .for lighting background environment texture (hdri) will make things easier to compare(instead of meshlights)- you can adjust background intensity or exposure.i think film response for both should be set to “none”

[DDD]

Those glasses in the first post made me really thirsty!
I did like the Cycles one better(didnt look which one was which)

[Bao2]

My take on it with Cycles:

[stuart.t]

very comparisons. I prefer octaine, I will try have a go with rendering in lux.

Out of interest I see the normal for at least the liquid don’t seem right, does this not matter for cycles?

Can you post your wood texture please.

[vklidu]

@Bao2: thanks for the test.
I think the title gives wrong feeling from ChrisH compared pictures. It’s more setup problem than renderer.

Anyway I red somewhere Cycles is not going to be physical perfect, It’s going to be more user “friendly” and in many cases use range 0-1 for setups.

[stuart.t]

Here is a render with Luxrender, most of the settings were guessed, and only being using Luxrender for about two weeks so setting could definitely be better.

11 hours

[ChrisH]

Just to be clear: This wasn’t to prove that one was better than the other, it wasn’t even meant to be a true comparison (sorry if my wording in the OP led anyone to think anything else). I was just playing around with the model, trying to get realistic looking bubbles. And then said: “Hey, why not test in both of these awesome render engines”.
And I know Cycles isn’t truly realistic, but it can be pushed to give near realistic results…

Rusted: Ok, good to know. I think I was about right with the fresnel. Still would be easier to enter IoR (Just like in current BI), but I have no doubt that it will be in future version of Cycles. :?)

Bao2: Looks great, I would recommend to lower the roughness of liquid though.

Stuart.t: I used texture from cgtextures.com or one of those sites (so I can’t upload). I’m working on creating a bunch of textures of my own (I’ll happily give away those :?D ).
Yeah the normals was pointing the wrong way (my bad…), but it doesn’t seem to have an effect in neither Octane or Cycles. But it will have an effect in Lux, and if I’m correct in that Cycles will get something similar to “volumes” in Lux (based on the, disabled, Volume panel), it will matter in Cycles in the future.
But I see that you found a wood-texture and the render looks great.

And to you that’s requesting a Lux-render, you got a good one from Stuart.t. I’m sorry, but as I said, this was just a fun little (weekend) test, I have no time to tinker with this further, I have a whole “box” with other projects to play with. :?D

On another note: Feel free to use this model (it will go up on my site under Freebies later on), you don’t have to credit me, but it is recommended and I’d love to see what ever you do with it! :?D

[flim]

May I know where can I download and install the Cycle render? Is it come with Blender by default?

[storm_st]

Cycles merged to main trunk some weeks ago, expect it in next oficial blender release, 2.61. You can wait, or try experimental build from graphicall.org, for me it useable since may. Cycles engine does not replace internal blender render engine, you can select any from menu.