Let’s Talk Render Engines: Octane vs Corona vs Redshift

There are multiple different methods for rendering 3D scenes these days, from built-in systems such as MentalRay or Arnold in Maya, to the magic spouting from Cinema4D. Other engines have popped up alongside these more mainstream systems, each boasting a long list of projects and accomplishments, and also a similarly realistic end-product.

When seeking out a new render engine things can get a tad confusing, though, and a lot of these newer bushy-tailed plugins seem to do a very similar job for those with experience in 3D texturing. A few years ago, those with keen eyes could tell what renderer was used based on what the final product looked like, but these days, the lines are blurred. That means your choice comes down to affordability, usefulness, and what you’re comfortable with. Today, we’re looking at three competitors: Octane, Corona, and Redshift.

CPU/GPU and biased/unbiased

Each one of these rendering engines works on a slightly different mix of CPU/GPU and biased/unbiased. For those who don’t quite know what this implies, here’s a very watered-down explanation:

The CPU is short for ‘central processing unit,’ and up until relatively recently was the main source of rendering power. Arnold, for instance, is a CPU-based renderer. The GPU, or ‘graphics processing unit,’ was originally sold to the public for uses such as 3D game rendering. Artists and programmers (among other unrelated fields) quickly discovered its programmability and potential.

If you have good hardware, a GPU-based rendering engine can spit out renders insanely fast- but again, if you have good hardware, cause that hardware can leave you with a rather large bill or tricky setup process.

Perhaps one of the best explanations of the differences between CPU and GPU processing power is by Kevin Krewell from Nvidia:

“Architecturally, the CPU is composed of just few cores with lots of cache memory that can handle a few software threads at a time. In contrast, a GPU is composed of hundreds of cores that can handle thousands of threads simultaneously.”

Now, onto biased versus unbiased:

• An unbiased renderer does its absolute best to compute your scene and lighting exactly as it is. Error or uncertainty will be rendered as noise, unless given enough time to resolve the errors to mathematical perfection. Arnold, yet again, is a good example, and an engine I’ve personally worked with. I have seen unpleasant graininess in difficult areas, which took a bit of fiddling to rectify.

• Biased renderers, on the other hand, are built for efficiency and speed. If there is an area that the program is uncertain about, it will do some calculations to fill in said area with perhaps a bit of blur or interpolation. Your end render won’t be mathematically perfect, but you’ll get more of them done. Biased renderers are also typically more customizable, and if you know what you’re doing, can produce an end result of similar quality to an unbiased render in a lot less time.

If you were going to match a specific job to these different techniques, I’d say that biased renders are good for high-volume jobs such as film and animation, whereas unbiased renders are good for still images, so they can be perfect. This is, of course, a personal take.

Let’s file this information away and move on to the three render engines in question, though.

Octane

First, we have Octane. On their website, the makers of Octane tout it as ‘the world’s first and fastest GPU-accelerated, unbiased, physically correct renderer’. This means it uses the powerhouse of a GPU to do the longer process of unbiased rendering, which seems like a nice compromise. You’ll need a CUDA enabled NVIDIA video card to use it, though, and they suggest having one of the newer, faster ones.

As for operating systems, the 64-bit version of Windows Vista, 7, 8, and 10 support Octane, as well as the 64-bit versions of Mac OS X and Linux. If you’re unsure about your hardware/software setup, there is a free demo and benchmark tool that will evaluate your computer.

Regarding workflow, Octane supports 21 different plugins, and imports geometry and materials through .obj and .abc formats from your original 3D modelling program (unless Octane itself is being used as a plugin). From there, you adjust the materials and lighting to your liking, keeping an eye on the viewport. Once you’re happy, increase your resolution and render settings. One thing to note is that Octane has a Standalone version, and a plugin to go with it. Unfortunately you can’t just get the plugin and put it in your host 3D program, you need the Standalone, too.

This is where things get a bit sticky with Octane. You need to buy a license for every active computer you use it on, because the software snatches its license from your account and only releases it once you close down the program. Even more complications arise when looking at Octane 3 versus Octane 2, the latter having a difficult and involved license activation process. Price-wise, expect to pay $400 for a single Standalone program, which is necessary to run the plugins. Those cost about +$220 on average if you buy them as a combo.

Despite the video card requirements and somewhat complicated licensing/pricing, Octane has an impressive resume in regards to ability and speed. So far, it has only been used in small projects by teams or individual artists. There’s a great community of these avid fans online, and Octane’s website gallery shows the quality and potential of its render engine. There are some experimental videos by smaller companies such as Bulwark, and a rather impressive animation called Reebot.

Not much can be found about large project involvement, though IAMAG Master Classes did use Octane to render a trailer for 2018.

Corona

Corona is a ‘proudly’ CPU based renderer with unbiased path tracing and biased UHD cache. It has a big material library and looks nice, but here’s the catch: it only works with Autodesk 3DS Max, and even then, that’s only a plugin. There are other program types in development, including Cinema 4D, Blender, and a Standalone version, but those are currently still in alpha.

Fortunately your hardware options are pretty vague and open, the creators say Corona will run on basically any PC that’s 10 years or younger- as long as it’s running Windows, because that’s the only system it will work on right now. Obviously they advise running their renderer on the newest computers, and have a legacy option for the older ones. There’s a little warning label, though, that says those older, legacy versions might chug up to 20% slower.

The software requirements are a bit confusing, since they differ from the currently available plugin to the alpha development versions.

• For Autodesk 3DS Max x64, 2012-2018: 64-bit Microsoft Windows (7, 8, 8.1, 10) (no MacOS). You must have access to administrator privileges. Distributed rendering requires matching Backburner version of program.

• For the alpha Cinema4D version: 64-bit Maxon Cinema4D R14-R19. Again, administrator privileges. 64-bit Microsoft Windows (7, 8, 8.1, 10) OR MacOS 10.7 or newer.

• For the alpha Standalone version: 64-bit Microsoft Windows (7, 8, 8.1, 10)

For those of you who use 3DS Max and can get Corona without jumping through a few hoops, it’s a plugin and supports mostly whatever you throw at it. So, what does this plugin cost? It’s actually a monthly price, set at 24.99 Euros. There’s no cancellation penalty, and you get one floating workstation license + 3 floating render nodes.

This might make it a nicer option for small businesses (if they have 3DS), and to support that, there’s a large artist network online and for festival films. Corona has been used in smaller projects such as:

• Forester project by Andrew Krivulya, a 3D fantasy world that used Corona as its main renderer.

• On My Way music video by Grand Yellow.

• Rendering in the movie Monkey Talks, January 2017.

Redshift

Out of the three render engines here, Redshift seems to be the heaviest hitter regarding company use. It’s a GPU accelerated, biased renderer, and supports a nice selection of 3D programs: Autodesk Maya, Autodesk Softimage, Autodesk 3DS Max, Maxon Cinema4D, and Houdini.

Redshift also works on multiple platforms, which is a bonus:

• Microsoft Word 64-bit (7, 8, 10)
• Linux 64-bit distribution with glibc 2.12 or higher
• MacOS El Capitan (10.11) or higher

The 3D program requirements are listed in detail on Redshift’s website, but for the sake of facilitating access to information, here’s a summary:

• Autodesk Maya (Windows, Linux, MacOS) 64-bit, 2014+
• Autodesk Softimage (Windows) 64-bit 2011+
• Autodesk 3DS Max 64-bit 2013+
• Maxon Cinema4D (Windows, MacOS) 64-bit R16 or higher
• SideFX Houdini (Windows, Linux, MacOS) 64-bit 14.0 or higher
• Katana (Windows, Linux) 64-bit 2.5v4 or higher

Apart from the stringent-yet-lenient software and platform requirements, Redshift is also very specific about its hardware requirements, setting both a minimum requirement and suggested optimal.

Minimum Requirements: 8GB system memory, SSE2 support (Pentium 4 or better) processor, NVIDIA GPU + CUDA 2.0 or higher, 2GB of VRAM, and a single GPU.

Suggested Optimal: 18GB system memory, Core i7 or Xeon equivalent, 3.0GHz or more, NVIDIA GPU + CUDA 5.0+, 8GB of VRAM, and multiple GPUs.

Phew! Ok, that was a lot of information. It’s nice that Redshift lists this, though, and that they developed their program for so many different programs and platforms. So, what does this all-encompassing render engine cost?

Well, you receive one node-locked (or floating) license per machine at $500. For this half-a-grand you get a render engine that does not distinguish between render nodes, and there’s no limit on GPUs (well… not exactly. The limit is 8 before you have to add other computers). If you want more licenses, you can get them for $600 (floating), and must get a minimum of 5. It’s a tad difficult to tell if they mean $600 per extra license, or $600 for all 5. You have to contact their support team to buy that option, anyhow, you can’t just add it to your cart.

Redshift distinguishes itself from the other two render engines when it comes to its claim to public exposure, being used from small teams on passion projects to companies as prominent as Blizzard.

Personally, the most notable films are the ever-popular Overwatch shorts by Blizzard, with millions of views and an avid fanbase. Apart from those, Redshift has been used in:

• Nike commercials
• Empire: Four Kingdoms commercials
• Heineken beer commercials
• Singing Babies for Cadbury commercial
• More Stuff by Blue Zoo Animation short film
• Many, many other short films all over the internet (it’s a very popular render engine)

So, what’s the rundown?

Redshift seems to be the popular, heavy-hitter here, allowing for a wide number of platforms and programs. Depending on how the floating-node-pricing works, it is also the most expensive of the three, and requires a decent computer.

Corona is CPU-based, which might make it more accessible for the regular artist. Its low price helps, especially since you get 3 floating nodes with your plugin. The problem with Corona is that unless you dig your fingers in and get the alpha versions of in-development-programs, you’re stuck with 3DS Max, which not everyone has access to without dropping some extra money.

Octane is the interesting child here. It’s very fast, has a good fan base, and a very promising future. You could consider it a breakout program, but it’s been around for 6 years with not much major news compared to Redshift, the other GPU-powered renderer. Buying a single version costs only $100 less than Redshift, but getting extra nodes seems to be less than half the price (again, unsure about Redshift’s pricing). I feel like Octane has a lot of promise, but still needs to catch on.

To be fair, all three of these render engines produce gorgeous final images, and seem to be built for different tiers of production and different purposes. Some are more affordable, and some are built for chugging out large products over many machines. They focus on different strengths of your computer, Redshift and Octane being GPU based and Corona being CPU based. All three have a free trial, so in the end, it may just be down to preference, and what software you already have and are willing to experiment with.

Referenced Articles

Ashley, Chad. “Octane vs Arnold vs Physical – What Renderer is Right for You?” GrayScaleGorilla. March 29, 2016, Acc. March 13, 2018

Krewell, Kevin. “What’s the Difference Between a CPU and a GPU?” NVIDIA. December 16, 2009. Acc. March 13, 2018

Pizzini, Joe. “GPU Rendering vs CPU Rendering – A method to compare render times with empirical benchmarks” Boxx. October 2, 2014. Acc. March 14, 2018

Slick, Justin. “Rendering Terminology Explained” LifeWire. February 19, 2017. Acc. March 13, 2018