Hardware review: Caustic Series2 R2500 ray-tracing accelerator card

| Hardware | Reviews | 16/04/2013 14:00pm
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Does the debut of this real-time card and Maya plug-in mean the future has arrived for 3D artists? Antony Ward finds out

PRICE: $1,495

OTHER MODELS: Caustic Series2 R2100, $795


  • Windows Vista or 7 (64-bit)
  • Maya 2012 SP2 or Maya 2013 SP2


  • Two Caustic RTU (ray-tracing unit) chips
  • 1 6GB on-board RAM
  • Up to 100 million incoherent rays per second

DEVELOPER: Imagination Technologies

We’ve all been there. The deadline is looming and you’re at the stage where your scene needs its final tweaks. The shadows, lighting and shaders must be perfect before you produce your final render. The problem is, of course, each slight change results in a tortuous wait while that section or element re-renders.

There are obvious clunky workarounds, but this is supposed to be the future, isn’t it? Granted, the science world failed us on the promise of flying cars, hover-boards and free energy, but come on: where are our real-time ray-traced viewports?

The Visualizer for Maya plug-in dramatically upgrades the standard viewport

As it happens, Caustic Professional, part of the Imagination Technologies group, has recently come to our aid with the release of its suite of Caustic Series2 ray-tracing cards, with the accompanying Visualizer for Maya plug-in. (3ds Max support will be with us later in 2013.) With these tools, you may finally have what you’ve been hoping for: the ideal preview render, sitting neatly inside your viewport. Sounds too good to be true, right? Well, it gets better. On top of this, the viewport is still active, meaning you can continue to edit your scene in that viewport, with the ray-tracing preview updating on the fly at lightning speed.

The Series2 cards accomplish this by using their foundations in Imagination Technologies’ PowerVR OpenRL technology to take control of the ray-tracing and scene-geometry calculations. The shading of the scene objects is passed over to the CPU, unlike with most GPU cards, and textures are thrown into the system memory so that the Caustic cards are free to focus on each ray and polygon. With the R2500 card capable of handling up to 100 million rays, larger scenes are taken in their stride. While visiting Imagination Technologies, I took the opportunity to try some of my own work with the hardware. I know these scenes and I remember how much of a pain they were to set up and adjust, so what better test of the setup?

My ‘Serena the Genie’ scene loaded, and I activated the Visualizer for Maya viewport (which is as easy as switching to Viewport 2.0): in less than a minute, I was looking at a near render-quality version of Serena the Genie. This was impressive to see, but I also wanted to try it on my own ageing Dell T3400 in a real-world setting.

Change shaders and reflections on the fly, like the lenses in this demonstration model

By default, the Visualizer plug-in will runs through 10 passes of the viewport, starting with a rough interpretation and refining the image with each pass. With the hardware disabled, 10 passes of Serena took four minutes and 30 seconds to complete. Enabling the R2500 Series2 card reduced this to a mere one minute and 33 seconds. If you consider this factor over the duration of a project, the time saved could be immense, especially if you removed all those tedious test renders you would normally need to endure.

The Series2 boards come in two versions, the R2100 and the R2500, containing 4GB and 16GB of memory. The first is suited to single-processor machines, whereas its beefed-up brother is aimed at dual-processor systems.

With that in mind, you don’t initially need to buy one of these boards to experience the Vizualizer plug-in: you can buy it separately for $299, and a 30-day trial is available. Obviously, the Series2 cards offer a significant speed improvement, especially on larger scenes, but it doesn’t hurt to try before you buy.


Before you empty your piggy bank and hit the online stores, there are a few things to consider. First, the software and drivers aren’t yet Windows 8 friendly, although the developers assure me that they are working on this and an update will soon be released. Second, when I say this is a fully ray-traced viewport, there are some limitations. Lighting, shadows, shaders and reflections look great, but character artists may miss the lack of subsurface scattering and nHair support. I also noticed that it seemed to struggle with a texture pathed into a ramp node. However, Caustic is listening to its users, and plans to continue to develop the software to incorporate more shaders, systems and effects in the future. It also hinted at the possibility of more application support: ZBrush and Mudbox, maybe? We can hope! Which reminds me to point out that the OpenRL SDK is currently available as a free download for anyone wanting to investigate support.

The R2100 only has 4GB of memory and a single chip, but it’s still a powerful model

So, should you buy one of these cards? Whether you’re a professional 3D artist or more of a hobbyist, downloading the plug-in is a no-brainer. It’s free for 30 days, which gives you plenty of time to decide whether to purchase a full licence, or boost your viewport’s speed with the addition of a Series2 card. If you’re a heavy renderer, though, this may just be the tool you’ve been looking for.



  • Affordable real-time viewport ray-tracing
  • Good support and future plans
  • Could drastically improve your workflow


  • No Windows 8 support yet
  • Limited shader and dynamics support
  • The plug-in alone is slow on old machines

With the Caustic Series2 Cards, Caustic brings real-time ray-tracing to the everyday artist at an affordable price


Antony Ward has been provoking pixels since the early 1990s. He has worked for some of today’s top studios

Posted on Tuesday, April 16th, 2013 at 2:00 pm under Hardware, Reviews. You can subscribe to comments. You can leave a comment, or trackback from your own site.

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