Affordable ray tracing renderer: Corona Renderer
Corona Renderer is a modern high-performance (un)biased photorealistic renderer, available for Autodesk 3ds Max, MAXON Cinema 4D, and as a standalone application. The development of this affordable ray tracing renderer started back in 2009 as a solo student project of Ondřej Karlík at Czech Technical University in Prague. Corona has since evolved to a full-time commercial project after Ondřej established a company together with the former CG artist Adam Hotový, and Jaroslav Křivánek, associate professor and researcher at Charles University in Prague. In August 2017, the company became part of Chaos Group, allowing for further expansion and growth.
Despite its young age, Corona Renderer has become a production-ready renderer capable of creating high–quality results. The latest versions for 3ds Max and Cinema 4D are currently available on trinity3d here.
Ease Of Use
No–one calls themselves a “3D Technician” – everyone rightly calls themselves a 3D artist, and that means your tools should be as close to invisible as possible so they don’t get in the way of your creativity.
Corona Renderer is one of the easiest to learn render engines. Its setup really is as simple as pressing “Render”! Most new users will learn Corona Renderer in just one day, and fall in love with this affordable ray tracing renderer over the next few.
Our mission with Corona Renderer is to liberate users from technical and unnatural processes. We are constantly trying to simplify the creative process by removing or hiding any unnecessary technical settings so that artists can focus on their vision. The era of studying manuals and tweaking sampling is over. Just press render and let this affordable ray tracing renderer do its magic.
Corona Renderer is developed in tight cooperation with the artist community. Its creators are former artists as well, so this collective knowledge and experience play a huge role in the design and ongoing development.
Corona Renderer is compatible with a huge range of third-party plugins, so you can continue to use any tools you already have integrated into your workflow – whether you are using Corona’s Interactive Rendering or doing a final render, you can keep right on using iToo’s Forest Pack and RailClone, Siger Shaders, Quixel Megascans, Allegorithmic Substance, Phoenix FD, FumeFX, Ornatrix, Hair Farm, and many more.
Corona Renderer is also compatible with the core V–Ray Materials and V–Ray Lights, which allows you to render those using Corona even if V–Ray is not installed. This is ideal for downloading V–Ray assets from model stores, or if you already have a library of assets in V–Ray format, or if you are studio using both engines, and so on.
Corona Renderer delivers predictable, reliable, and physically plausible results with no compromises in quality. Realistic lighting and materials are yours right out of the box.
New in Corona Renderer 4, the Fast Caustics Solver lets you easily add caustics to your scene. Once enabled, reflective caustics are calculated automatically for all materials in the scene. You can then enable refractive Caustics per material. For further control, you can choose to disable caustics for individual Corona Lights, and render caustics to their own Render Element for manipulation in post-processing. Caustics also respect the include/exclude lists of Corona Lights.
Corona Renderer offers both biased and unbiased rendering solutions. By default, Corona Renderer uses a slightly biased solution, very close to being unbiased but considerably reducing render times. This is the recommended solution and works without you having to do any setup whatsoever. Corona Renderer will always deliver crisp, realistic results without splotches, interpolation artifacts, or any other visual imperfections.
Traditionally, you had to choose between using unbiased algorithms with no caching and accept long render times, or using biased caching algorithms and deal with splotches, missing shadows, and sensitive input parameters. Corona Renderer merges the best of both worlds – the UHD cache is significantly faster than plain path tracing, but does not suffer from artifacts, missing contact shadows, or complicated UI controls. The UHD cache uses only partial caching, so does not try to interpolate everything. While this is slower than a fully cached solution (such as irradiance caching), it does not create artifacts, the only noise that eventually goes away. The UHD cache is an ideal solution for animation and significantly reduces flickering even when light sources or geometry are moving. This is especially important when the cache cannot be precomputed.
Speed & Interactivity
Speed is an important factor in any production environment, and a renderer must always deliver results as fast as possible. As a result, we are obsessed with speed! We like to hunt for milliseconds in our own code and are always looking for ways to cut down parsing and rendering times without forcing users to buy expensive hardware, by focusing on creating smart algorithms under the hood. In every version we release, we look to boost the speed of rendering as much as possible as well as adding new features.
Corona Renderer uses Intel Embree Ray Tracing Kernels, making the CPU–only Corona as fast as many GPU renderers but without any of the limitations of GPU–based solutions.
The denoising feature analyzes noise in the 3D space, so is not just a 2D post–process. You can use it to reduce the number of passes needed to get a noise-free image, with render time reductions of 50 to 70% reported to us by third parties in commercial usage (not in carefully crafted test scenes!). It will also remove fireflies (hot pixels) from an image, and can be used only in that mode if required.
Denoising is seamlessly integrated into the core as a one-click solution. The denoising level can be interactively adjusted in the VFB after rendering is complete so that you are not locked into the level set in the rendering options. This lets you check and adjust the blending between the regular and the denoised image without having to re-render. You can also calculate Denoising in the Corona Image Editor rather than at render time and without the overhead of working in a 3D application. To learn more about it, you can watch the tutorial from when Denoising was released: Corona Renderer aims to make you faster as well as your renders, with a workflow that is second–to–none. Thanks to its fully-featured Interactive Rendering, Corona Renderer brings you all the same advantages as a GPU render engine but without any of the drawbacks and limitations.
You can change materials, lights, and create or adjust geometry and see your interactive render respond almost immediately. It runs completely on the CPU, so it has no limitations and won’t care what graphics card you have installed.
The NVIDIA OptiX denoiser is the only denoiser that you can use during Interactive Rendering and gives you a noise-free image in record time.
You aren’t limited to using it only for interactive rendering, however – you can also use the GPU denoiser for final renders too if you choose. Note that this denoiser requires a compatible NVIDIA graphics card. Standard denoising uses the CPU only so can be used with any graphics card.
This AI denoiser for final renders offers a balance between quality and speed. It is purely CPU–based so you can use it whichever graphics card you have, and it runs on any CPU (not just Intel).
Our interactive rendering is an integral part of the Corona core and shares over 99.9% of the regular renderer code. This means that all features of Corona Renderer are supported and that the results are exactly the same as your final render – you can render motion blur, DOF, create proxies, scatter systems, and more, all with instant feedback.
Because our interactive and regular renderer is almost identical, all types of geometry and proxies are supported, as are almost all 3ds Max maps and third party maps. Even advanced third-party plugins, such as Itoo Forest Pack, hair and fur from Ornatrix and Hair Farm, simulations from PhoenixFD, and FumeFX are supported. Core V–Ray Lights and Materials will also work in Interactive Rendering, even if V–Ray is not installed. Check out which V–Ray features are supported – and support will be growing in the future for this affordable ray tracing renderer.
Interactive Rendering also offers as many render regions as you like, which can be moved and resized as you choose. This means that so that they can act as a “sample brush”, letting you paint–in areas that you want to refine faster or inspect at better quality.
Corona handles scenes with many lights without problems and with no penalty to render time, so that you don’t have to worry about trying to optimize your scene.
This balances out the rendering calculations over the image to focus more processing power on tricky areas like shadows. By keeping noise more evenly distributed, this gives a usable image more quickly, and also allows Denoising to work its magic. Coupled with the new High-Quality Image Filtering introduced in Corona Renderer 4, which gives a much more natural and less CGI look to the noise, and your images will be noise-free faster than ever!
We had the luxury of being able to do things differently right from the start, and we took advantage of that not only in development but also when creating our licensing plans.
We have two simple goals:
- to make Corona Renderer an affordable ray-tracing renderer for as many users as possible, and
- to secure reliable funding for the development of Corona Renderer so that it keeps improving.
Corona is actively used in 143 countries around the world, and that means the average wage for our users can differ by a factor of 20. Even with today’s internet, most CG artists work for local customers, and that means at local prices.
We want to offer our product to the broadest audience around the globe for a fair price that would suit everyone. Traditional perpetual license models don’t fit this concept as they require a large upfront investment, which is unaffordable to many. That’s why we came up with the solution that we call FairSaaS licensing.
- This is a subscription-based model without the common problems and hassle that come with the traditional SaaS/subscription options. It is paid monthly, so it completely eliminates any upfront investments and can be canceled, resumed, upgraded, or downgraded as you go, without any additional penalties. This keeps corona render an affordable ray-tracing renderer for everyone.