RandomControl Arion 2 stand-alone
arion :: real-time digital photography

Arion 2 - The hybrid Renderer

Because the most demanding productions require the sharpest tools, we have created Arion 2.

Packed with unprecedented flexibility, speed and output quality, the new Arion 2 technology is at the heart of our stand-alone renderer as well as the MAX LIVE and RHINO LIVE plug-ins.

What is Arion?

Arion is a hybrid-accelerated and physically-based production render engine. It inherits all our expertise in light simulation and makes it run on steroids, thanks to our very unique massively parallel GPU+CPU approach.

Arion is a high performance production renderer capable of producing hyper-real images.

Arion's unique approach

Arion uses all the GPUs -and- all the CPUs in the system simultaneously, not wasting a single flop available. Additionally, Arion can use all the GPUs and all the CPUs in all the other computers in the network forming a cluster for massive distribution of animation frames.


Arion 2 is able to handle very large data-sets and still deliver a very good performance. By means of using instancing, render-time displacement and render-time subdivision surfaces, it is possible to render virtually anything on a modern hardware-accelerated computer using Arion.


Arion 2 can handle most of the rendering effects which are considered standard these days such as displacements, instancing, motion blur, ... and more. And beyond the current feature list of Arion, we keep researching and developing to bring even more features in the near future.

Stable and rock-solid

The Arion 2 technology has been crafted with the highest coding quality standards in mind. As a result, its rendering core is nearly unbreakable and will relentlessly render for hours or days without ever crashing.

Key features: Interactive rendering and editing, CUDA empowered, displacement, photo-realistic materials, physically-based, unbiased...

Arion is fast, very fast

Arion raw raytracing speed is vs. quality ratio is unprecedented and can produce the cleanest and the most beautiful artworks.

Thanks to its carefully engineered rendering core, it outputs an astonishing amount of work in the same time as traditional renderers.

Beside a deep optimization of the core that affects raw speed, Arion 2's new sampling strategy leads to an even faster image convergence.

This excellent performance applies to all the different samplers in Arion 2, including Metropolis Light Transport (MLT).

LightMixer layers

LightMixer light layers are back.

It's now possible to output all the LightMixer layers in a multi-layer EXR file and tune it in your favorite editing software such as Photoshop, After Effect, Nuke...

Just like AOVs, LightMixer layers are computed on the fly during the standard calculation of the full unbiased render or AOVs.

With this method, it's now possible to re-light in full 32bit floating point a complete animation sequence with any software that supports EXR and multi-layer EXR without the need for extra plugins or limitations due to proprietary formats.

Arion v2.4.0 offers up to 8 LightMixer channels, plus the environment and sunlight channels, summing a total of 10 exploitable channels.

RandomControl has been working with FnordWare to provide you the best multi-layer EXR output possible. We strongly recommend their plugin ProEXR to read multi-layer EXR files in Photoshop and After Effect. Other softwares such as Nuke handle this natively just fine.

Metropolis Light Transport

For the first time on a full-featured renderer, Metropolis Light Transport can run on the GPU.

This is not a MLT look-alike or simili-MLT amputated from its glory to run on a GPU, it's the true, fully-featured Metropolis algorithm.

And as always with Arion, it's hybrid and can run on your GPUs, your CPUs or all at once.

Metropolis sampling can help get out of previously impossible rendering situation and produce an astonishing output.

The render above has been completed in a few hours on 2 Geforces GTX 580, missing no light component at all. The blue beam that is seen in the total internal reflection of the most left prism for example, is a very hard case for most renderers. Arion does it just right and noise-free.

Although MLT can be used on any kind of render, it has a great use in optical and lighting simulations.

If you're a professional working in optics or lighting, Arion is the right software for you, providing unprecedented speed and image quality, cutting no corners for a fully accurate physically-correct simulation of light.

The rendering on top of this page is also using the power of MLT to render underwater pool caustics accurately, with full dispersion.

Very large renders on the GPU

Arion v2.4.1 introduces a brand new framebuffer feature that compromises just a little performace, to allow very high resolution rendering.

This feautre called 'Dicing' is part of the supersampling paremeters group.

It allows you to render up to 16,000 x 16,000 pixels images on the GPUs, and much more on the CPU.

In fact, over 16k, you're far from hitting the memory limits of the GPU (about 350B for such buffer), you're more hitting a hardware limit itself.

When you are stranded on a scene that needs to render at very high resolution, dicing may help you get the job done at a little performance cost.

This feature would be particularly usefull to render complex animation in large formats like IMAX.

Click on the image above to see it full size.

Here is a comparative table of memory usage versus performance when using dicing and SuperSampling:

1080p render No SuperSampling 1x1 SuperSampling 2x2 SuperSampling Framebuffer Memory
No dicing 1.53 Msamples/sec 1.53 Msamples/sec 1.53 Msamples/sec 40 MB
Dicing 1 level 1.49 Msamples/sec 1.49 Msamples/sec 1.49 Msamples/sec 10 MB
Dicing 2 levels 1.27 Msamples/sec 1.27 Msamples/sec 1.27 Msamples/sec 3 MB

Render channels

Model and render courtesy of Hektor Perez.

Arion 2 extends the existing render channels, adds new ones and makes their usage more productive than ever.

Arion 2 can render all the render channels (now called AOVs for Arbitrary Output Value) at once along with the regular full unbiased render.

Here is an exhaustive list of all AOVs available in Arion v2.4.1:












Material ID (custom or random)

Object ID (custom or random)







Ambient Occlusion

LightMixer (see dedicated block below)

It's possible to define a custom range of roughness to set apart specular-glossies-diffuse materials to send the appropriate pixels to their respective AOV, giving you full control on your output.

All these channels can be output to 32-bit float HDR, EXR or multi-layers EXR.

RandomControl has been working with FnordWare to provide you the best multi-layer EXR output possible. We strongly recommend their plugin ProEXR to read multi-layer EXR files in Photoshop and After Effect. Other softwares such as Nuke handle this natively just fine.

*** RandomControl's Arion 2 is available for purchase ***

Purchase a copy of the RandomControl Arion 2 today!