Render Engines Help: Lux Octagon Reality and so on...for DAZ Studio

rnollman

What are the pros and cons, strengths and weaknesses, and reasons for using for the different render engines like LUX, Octagon, Reality and so on, available to do DAZ scene renders?

If you have a scene and want to use these different render engines, how do you go about getting them and how do you use them to render your scene?

Exeriences would be helpful and why people prefer one over the other. I have been using 3Delight. I tried IRAY but render times were too long and I did not see any particular advantage. I liked the 3Delight renders better. But hearing about LUX, Octagon, and Reality made me wonder if I am missing something important.

SimonJM

The 'other' render engines tend to be PBR (physical based render) engines, and as such handle lighting with realism.  They also tend to have material definitions that reflect real-lfe properties of materials.  Iray (the new render engine included in DS) is one such engine.  LuxRender (usually accessed via Reality or Luxus) is another and Octane (usually accessed via OcDS) is one more.

Advantages tend to be toward the realistic lighting (if it works in real-life it pretty much should in the render engine), and in particular global illumination caused by reflection of ambient light off surfaces.  Disadvantages tend to the longer render times, although with use of suitable GPUs this can be reduced quite dramatically.

scatha

Basically what it generally comes down to, is that if you want things  fast, you need a powerful graphics card. Iray isn't slow if you're prepared to pay  for a high end card (Nvidia 980ti or Titan card with lots of cuda cores) ... consider also that getting a different renderer, you limit yourself in the amount of people that can help you (experience with said render engine, be it luxus, octane or reality)

FSMCDesigns

if you tried Iray and it was to long for you and you like 3delight, then the others are not for you. Personally, I prefer unbiased renderers (unlike 3Delight) because I like knowing that what I see is how it is, and not the app or my preferences determining how the light should interact with the scene and the surfaces. Think of it this way, with biased renderers like 3delight, you are telling the light how to interact with the scene and the surfaces. With unbiased renderers, it's the other way around.

I usually let my renders run overnight, but I am used to it.

StratDragon

Reality is not an engine, it's a bridge application that takes your scene in Studio and converts the shaders on your objects into a compatible LuxRender scene. While LuxRender renders can take several hours I tend to run mine overnight as well but the results are far more impressive that what I can accomplish in 3Delight, Iray or Cylcles. LuxRender allows you to  adjust lighting (globally or individual lights) while you render which the other three engines I mentioned are incapable of doing. It also does not require proprietary hardware and it's free. Lighting for a scene to be rendered in LuxRender is the same procedures as a photographer would use to photograph a scene so there is not trickery to getting lights to work and outdoor scenes which were impossible for in 3Delight could not be easier in LuxRender (create a distant light named sun, position it, render and set the exposure to the Sunny 16 rule used by photographers.) 

While Iray allows you to use multiple (but ONLY nvidia) cards in the same computer it's limited to the VRAM on a single card so if you have three Titan X's with 2048 Cuda cores 12GB VRAM each which totals 36 GB VRAM come render time you will get 6144 cuda cores but the VRAM will be maxed at 12 GB since Iray does not combine your actual total. If you mix and match and you have a card with 2 GB VRAM, one with 4 GB VRAM and one with 8 GB VRAM and your scene uses 4.1GB VRAM the other two card will stop assisting the render altogether. The same can be said for LuxRender if you network render, you can use all the cores of the CPU' you link but if your scene takes 4.1GB RAM to render and you have a computer with only 4GB RAM available the computer with insufficient RAM to render the scene as if it were rendering it alone will not be able to assist but it's not tied to a proprietary hardware developer so Intel CPU's, AMD it doesn't care. A 4GB AMD/ATI GPU can be had forless than a comparable NVIDA offering in many cases, but since Iray wont use AMD/ATI it's not an option for you.

If you want perfection with zero wait the technology is not quite there yet. 

DustRider

I also prefer unbiased renderers. My Iray and Octane renders are also faster than what I was getting for final renders in 3delight (but I tend to use UE2 and higher quality settings). Will a good Nvidia graphics card, both Iray and Octane can be quite quite fast (fast being relative). It really depends on what style your after, take a quick look at my galleries (links in my sig line below) to see if these are the type of renders you are looking for. If so, then Iray, Reality, or Octane may be woth the extra time and/or effort.

My personal bias is toward Octane, because the "real time" preview is much faster than Iray, it renders a bit faster, takes fewer system resources (Iray will consume 2 CPU threads in GPU only mode, Octane uses vrtually no CPU while rendering) and has features Iray doesn't. For example, Octane supports out of core textures, which means you can render scenes larger than what fit onto your graphics card memory. For example, just messing around, I rendered 8 fully clothed G2F characters (with hair) in Stonemasons Village Courtyard on a system with a 3Gb GTX 570M, no way could I do that with Iray on a 3Gb card. Octane also has motion blur, shader based hair (not available the DS plugin, but it is available in the Octane plugin for Carrara), network rendering (requires an Octane standalone license for each computer used),  and the new version that will be coming out soon (next year?) will also remove the 19 million polygon limit and have true volumetrics (the beta of Octane 3 is now available for testing via the DS plugin). A few months ago I would have advised against Octane for DS, because the plugin development was ...... well .... very very very slow, and well behind where it should have been. But a new developer took it over (face_off, the same person who developed the Poser plugin), and development is back on track, and IMHO the plugin is worth the investment again..

That being said, Octane is a significant investment in both funds and to a certain extent learning.You would need to learn to modify and setup your own shaders more so than with 3Delight or Iray. I would suggest using either Iray or Reality/Lux for most people, but if render speed is very important., or you need some of the features available in Octane that aren't available in Iray (or Lux), then Octane is a great choice. Just keep in mind that you will have great vendor support going forward with Iray, and with good hardware (GTX 960 is a quite good entry level card) you can get great renders in a few minutes to a few hours (depending on scene, shader, and lighting complexity). on my system (a laptop with a GTX 970M) a typical portrait style render with one Genesis figure will take less than 10 minutes. 

Bottom line though, if your quite happy with the results your getting with 3Delight, then there really isn't any reason to change. If your interested in moving to an unbiased, or PBR renderer, the price (free) and integration of Iray is hard to beat. The other options have their own unique advantages that may make one of them a better fit depending on you own needs and situation.

Hiro Protagonist

If you are finding Iray slow, and you are basically not finding any advantage in using it, then your problem is hardware. It's likely that Octane and Luxrender will perform even worse than Iray in that respect, and you are likely to find them even more difficult to use. 3Delight is a biased renderer, which, to put it simply, means that the number of calculations necessary to complete a render are drastically reduced (although if you use more advanced shaders and lighting renders can still be long).

I thoroughly recommend Iray, and there are great advantages in using it in terms of realism, but you do need the hardware to support it. DustRider has covered most of the other points and advice I would give and I absolutely agree with Dustrider's last paragraph—I really couldn't put it any better.