Iray and Octane Render for DAZ Studio: Which Graphics Card is Best?

With Iray coming to DAZ Studio it is becoming harder to ignore CUDA/Nvidia powered rendering. Of course, Octane has offered support for DAZ Studio a number of years, but for some with AMD cards (no CUDAs) then the price of a higher end Nvidia gamer card and an Octane licence may be a little on the hefty side. And now we have Iray – It’s there, it’s free to use, and it is already well integrated into DS. This is a very nice marketing move by Nvidia. It also works out great for DAZ as they have wanted to incorporate simpler GPU rendering solutions for a long time.

Unbiased physically accurate/plausible GPU rendering is great. Lights always behave realistically, you get that nice bounce of light and blending of colour. In short, unbiased takes so much of the pain out of lighting a scene, especially when quicker, more realistic renders are the order of the day. CPU driven physically plausible/accurate rendering has been around a long time, but it has only been recently that the hardware made it financially viable to go this direction for large-scale production. There was an interesting article in a recent 3D Artist magazine that discussed how incredibly complex and painstaking lighting arrangements had become for Pixar movies prior to adopting global illumination (GI).

Anyone else go along to see Monsters University and realise Pixar had just changed the way they worked? Well, that’s GI, and it’s glorious! But just as this was happening with titanic farms of CPUs it seems that the GPU is poised to take over, doing it faster and cheaper.

BMW Iray render - Maya courtesy of Nvidia

BMW Iray render – Maya courtesy of Nvidia

Sure, most people who come to this little blog aren’t working at Pixar on hundreds of millions of dollars movies, but that’s not to say we don’t see the benefit and joy of working with lights that behave as physics intended (or close there enough to). Being able to work with these tools with the huge speed increases on mid – high end gaming cards means we can experiment and get much faster feedback, and for me that’s the greatest thing of it all.

So, in the interest of getting the best bang from a limited budget I set about finding the best card for me. Before we get to that there are a couple of points that need to be demystified.

1. There is no SLI.
I’ve seen many people make this mistake and run off to buy as many shiny cards as they can stuff on their motherboards. There may be some engines out there that do take advantage of SLI (Nvidia’s Scalable Link Interface), but neither Octane nor Iray support it.

2. Multiple video cards
If you are one of those that stuffed your motherboard with graphics cards that money is not necessarily wasted. You may go faster, just not bigger. Octane and Iray, (and as far as I know) all CUDA engines require a scene to be loaded fully onto all cards. The card with the least amount of RAM is the limiting factor here. If your scene won’t fit on a card then the render engine will ignore that card.

3. AMD = no CUDA. Sad, but true. There are some render engines out there that support OpenCL (which both AMD and Nvidia support) and CUDA (Nvidia), like Indigo Render, but CUDA is still the most common framework for GPU render engines and will only work with newer CUDA enabled Nvidia cards.

CUDA Enabled Card Selection Criteria

GeForce_GTX_TITANX_KeyVisualTo business! When deciding which cards to consider benchmarks were my go-to. These give a solid indication of which cards perform the fastest. Benchmarks for both Octane and Iray tell a pretty consistent story; for your buck, gaming cards are where it’s at. They also point out that newer is not necessarily better. I’ll point out right now that I’m not looking at particular brands of cards, just the Nvidia reference specs. I don’t endorse one brand over others, but I do endorse CUDA to CUDA.

Along with benchmark result, the other factors I take into consideration are:
1 Number of CUDA cores (which has a tight correlation with said results)
2 Amount of RAM (which has little to do with benchmark results)

The cards

GTX Titan X

3072 CUDA cores
12GB Ram
In the ideal world where price was not an issue every 3D artist would have one of these in their rig. Unlike its predecessor the Titan X really is the king of the hill. It’s fast and packs more RAM than many cheaper off the shelf gaming PC’s come with. The 12GB of DDR5 RAM is the primary factor of the card’s price.

Titan X @ Newegg.com

GTX 980 Ti

2816 CUDA cores
6GB RAM
In terms of performance this is my runner-up. With only marginally fewer CUDA cores than the Titan, it’s damn fast and still packs plenty of RAM.

GTX 980 Ti @ Newegg.com

GTX 980

2048 CUDA cores
4GB Ram

GTX 970

1664 CUDA cores
4 GB RAM

Both these cards can’t be dismissed, but they are rather underwhelming. Though the 980 does have more CUDA cores (and benchmarks justifiably higher) than the 970, the 970’s cheaper price makes it attractive when considering they both have the 4GB of RAM.
GTX 980 @ Newegg.com
GTX 970 @ Newegg.com

GTX 960

1024 CUDA cores
2 – 4 GB RAM

A decent entry level card of the current generation.
GTX 960 @ Newegg.com

GTX 780 TI

2880 CUDA cores
3 – 6GB RAM

This card is a true gem (though not literally). You can still buy these cards new from Amazon and Newegg, but here in Australia they are hard to find outside second-hand eBay auctions or classifieds. Though the newer Maxwell CUDA cores are purportedly around 25% more efficient than those in the 700 series of GTX cards, the 780 Ti benches better than most of the newer generation of cards.

The common variants out there may only have 3 GBs of RAM but this card wins my benchmark to cost ratio. It is an utter travesty that we haven’t seen more 6GB variants of this card.
GTX 780 Ti @ Newegg.com

Which Card Did I Pick For Iray?

If you have the dosh the Titan X and 980 Ti look great. If you want something cheaper the 780 Ti is still a very competitive card, though most have just 3GB of RAM. Finding one with 6 will likely come in at a price comparable to a 980 Ti. On a pure cost to performance basis it is hard to recommend a 980. For its price the 970 is a solid card. The 960 still has as much RAM as the current crop of 980 and 970s, which is still more than most of the older cards, making it a worthy Iray/Octane entry level card.

So, I went and did it. I picked up a GTX 780 Ti off eBay for a modest price. This “little” card takes the DigiSprawl Budget CUDA Choice Award.

The GTX Titan X takes the Starving Artist Wishlist Award.


News Roundup – Poser, Renderman Non-Commercial

Poser Pro 2014 On Sale

Poser’s back on sale at 55% off. There’s that and then it seems Poser 10 has dropped in price significantly to just $69.99. Not sure when this happened, but if you can live with rendering with the 32-bit limitation, then it’s a good buy.

Poser Service Release 5.2

Along with the sale, Smith Micro has pushed out the “5.2 service release”, which includes a bunch of enhancements and fixes. I hadn’t updated since service release 2, so it was a nice surprise. Installed just today. As only an occasional user of the software I haven’t noticed much of a change, but there are likely others out there that are eager for their fixes and boosters.

Renderman Non-Comercial

The really big news comes from Pixar, who have just released a fully featured non-commercial release of their wildly famous Renderman. While this is super-cool news, it’s also somewhat muted by the fact that Maya and Katana are the only programs currently supported by Renderman directly via plugins. There are a number of other programs that have various levels of compatibility with RM. DAZ Studio with it’s tight integration with 3Delight (which is Renderman compliant), can export RIB files, which can be readily rendered with RM standalone. Poser, as far as I can tell is also RM compliant and can also export RIBs. So, great news, and ok news right there.

Commercial versions of the engine have had a huge price cut. Happy 25th birthday to Renderman!

Iray Tests

And just because, here’s a few tests I did recently with Iray. Happy days!


Iray by Jim-Zombie on DeviantArt

Unbiased (PBR) GPU Rendering in DAZ Studio with Iray

*See this article for graphics card suggestions.

DAZ Studio DAZ Studio users have been enjoying unbiased, physically based rendering (PBR) via GPU for a good while now. The go to for many users up till now has been LuxRender via the Reality and Luxus series of plugins. Octane and it’s tightly integrated plugin for DAZ Studio has been embraced by both, professionals, and enthusiasts with more cheddar to throw at their hobby. Now with DAZ Studio 4.8x (aka Project Iradium – a clever little play on words), DAZ 3D has gone big and, thanks to a recent deal signed with Nvidia, brought production grade unbiased GPU rendering to the masses.

Not familiar with Iray? Just type “Iray” into Google and prepare to have your jaw dropped. The exact details of the deal aren’t clear. I’ve contacted D3D for comment and will post any details that come to light, but any way you slice it, unbiased GPU at this level is a very cool tool to have tightly integrated into DS, especially when sitting alongside 3Delight, DS’s long-time primary render engine.

In this article:

  1. The usual explanations – CUDA, OCL, Unbiased etc (for dinosaurs and noobs)
  2. Basics of using Iray – surfaces and rendering
  3. Iray vs LuxRender

CUDA, OpenCL, Unbiased, GPU – What Does It All Mean?

There is still a good deal of confusion in the community about CUDA, OpenCL, unbiased rendering, and GPU based rendering. As some already know, and others will guess, Iray is a CUDA based engine, so those with newer and beefier Nvidia cards (ie. those with more CUDA cores) will have the most to gain from the new engine. Those with AMD cards (myself included) miss out on all the accelerated goodness, but luckily, we can still make use of Iray as it also includes CPU options.

So, the short:

CUDA is strictly a technology accessible to only those with Nvidia cards

Iray is CUDA reliant for GPU modes of rendering, but those with cards without CUDA cores can still make use of Iray’s CPU modes.

OpenCL is supported by both AMD and Nvidia, but AMD have adopted it to a greater extent. Most examples of programs that utilise OpenCL tend to be much faster on AMD cards.

Unbiased rendering algorithms simulate the way light interacts with geometry and materials in such a way that the results are physically plausible, sometimes to the point where observers are unable to determine the difference between a photograph and a 3D rendering. It is therefore easier to light a scene for unbiased rendering than for one that will be rendered with a biased engine, which often require the placement of more lights and wizardry to produce plausible or aesthetically pleasing results.

The trade-off that has kept unbiased engines in the domain of super geeks and the artistic fringe is that all those simulated photons and surface interactions are incredibly expensive, in terms of processing power. For film and television all those extra cycles can quickly blow the budget. In recent years the massive parallel processing power of graphics cards has seen the development of software to move the burden off the CPU and onto the GPU.

That’s the basics, and in a few short years anyone that happens to read this will smile at my quaint assumption that such things still need to be explained.

Using Iray: The Very Basic Basics

Iray stuff in action.

Iray stuff in action.

Getting The Latest DAZ Studio Public Beta

If you have not yet picked up a free copy of a beta from the DAZ store, pay a quick visit to the DAZ Studio Beta page and add it to your cart. If you have already participated in a beta from the post 4.5x days you can download it from DIM or your product library on DAZ 3D’s site. The steps are a little convoluted for DIM, but if you check out the beta thread on the forum you’ll get there. [Ed] Somehow I missed the fact that the beta page also includes screen caps to show the exact process for installing with DIM.

Surfaces

DAZ have clearly done a lot of work integrating Iray into DAZ Studio. Though the current offering is still a public beta it is easy to get up and running with Iray in minutes. The default DAZ shader translates quite effectively into Iray, as does Age of Armour’s Subsurface Shader Base (SSB), but for best results it is suggestible to apply the Iray ubershader or a fitting shader preset. These presets are all easy to access from Surfaces (tab) > Preset > Shaders > Iray.

Anyone that has any experience SSB or UberSurface should be able to quickly recognise the various inputs and controllers. There is also a pretty darn good preset for G2 characters, though I think it works best for those of lighter skin.

 

Rendering

Rendering is also a breeze. Render Settings (tab) > Engine > NVIDIA Iray. In many cases you can simply hit render. There are some options to play with, especially when it comes to playing with the sun/sky model and tone mapping. Think photography on the latter there – all very familiar to Lux users and photographers, though the values and controls seem to produce some odd results.

45 mins to render? Don't recall exactly now

45 mins to render? Don’t recall exactly now

 

LuxRender Vs Iray

There has been a good deal of debate on the various community forums whether Lux or Iray is faster in both CPU and GPU modes. Given that I’ve slipped behind on LuxRender in recent times I don’t have anything solid to add to the debate. With CUDA and Iray being more mature than both OpenCL and LuxRender I’d take a punt on Iray in both cases. For those willing to forego the most physically accurate results Lux probably has the upper hand as both Luxus and Reality expose a number of Lux’s alternate algorithms, which can produce some great results quickly.

A bonus of Iray is that DAZ have implemented a very nice progressive preview viewport option. This means we can see all the tweaks we make rendered before our eyes in a close approximation to how our final render will look. Compare this with Luxus’ preview, which is perhaps marginally faster (and more restrictive) than exporting to the Lux GUI. Of course, 3Delight users have been enjoying a progressive preview since the DS 4.7x general release.

I have noted that the Iray viewport preview, at least on my CPU, lags and crashes Studio if I ask too much from it too quickly. Given the CPU intensive nature of the preview this is not unexpected, but hopefully DAZ will have a solution to minimise this inconvenience, assuming this is a problem for CPU users in general, and not just me.

The one department Lux stands head and shoulders over the current implementation of Iray in DAZ Studio is its external GUI. With Lux’s GUI you can alter tone mapping and light settings on the fly, along with adding and configuring post effects such as bloom and vignetting. Hopefully we will see similar features for Iray incorporated into the DS GUI.

With OpenCL, and the render engines that utilise it, still playing catch-up to Nvidia’s CUDA technology it is likely plugins like Reality for DAZ Studio will take a hit, but with AMD cards remaining considerably cheaper than those offered by Nvidia , and with more advanced rendering algorithms moving into LuxRender’s pure GPU, it is likely that Lux and Reality will be with DAZ users for years to come.

Conclusion: Being a lover of new toys I am once again considering Nvidia cards against a list of priorities.