Corona for 3ds Max
Corona Renderer is a new high-performance (un)biased photorealistic renderer, available for 3ds Max and as a standalone CLI application. Corona Renderer 1.5 delivers high quality, physically-based shading in production rendering. All of its features are tightly integrated into Autodesk 3ds Max. The development of Corona Renderer started back in 2009. Despite its young age, Corona Renderer has become a production-ready renderer capable of creating high-quality results.
Corona Renderer offers both biased and unbiased rendering solution at the user’s discretion. In both cases it delivers predictable, reliable, and physically plausible results with no compromises in quality. Our Forum and Gallery section provide great examples of this.
Rendering by Bertrand Benolt
You can render in a fully unbiased mode and use advanced rendering algorithms like BDPT/VCM to get the most realistic, true-to-life results. Or you can use the defaults, which is a slightly biased solution. This is very close to being unbiased, however it considerably reduces render time and increases flexibility. This is the recommended solution as it works straight out of the box with no setup whatsoever. Even in this mode, Corona will always deliver crisp, realistic results without splotches, interpolation artifacts or any other visual imperfections.
Rendering by Eduard Callman
Usability is our strongest weapon, as Corona is one of the easiest to learn render engines. Its setup is really as simple as pressing “Render”. Most new users will learn Corona in just one day, and fall in love with it over the next few.
Rendering by Dmitry Grankin
Our mission with Corona Renderer is to liberate users from the technical, unnatural process that rendering was in the past. We are constantly trying to simplify the creative process by removing or hiding any unnecessary technical settings, so artists can focus on their vision. The era of studying manuals and sampling tweaking is over. Just press render and let Corona do its magic
Rendering by Dmitry Grankin
Corona Renderer was developed in tight cooperation with the artist community
. Its creators are former artists as well, so this collective knowledge and experience played a huge role in the design and development. We call this approach A.D.D. – Artist Driven Development
Rendering by Andre Holzmeister
Corona Renderer is extremely flexible. We understand how important it is to be able to “bend” physical laws to deliver the results your clients expect. So Corona supports numerous reality hacks which allow you to get exactly the effect you desire.
You can make any light source invisible to the camera, as well as invisible to reflections/refractions. Shadows can be turned on/off and specific objects can be included/excluded from receiving illumination from any Corona light. Backplates can be easily created with the invisible to GI option. 3ds Max default lights are fully supported.
Rayswitcher material and texture allow a wide range of artistic tweaks when rendering with Corona. Use them to create materials invisible to camera or not affecting GI, to reduce or increase color bleeding, and more.
You can use different environment maps for reflections, refractions and direct visibility from the camera. For example you can use a clear sky HDRI as a light source and a second cloudy HDRI just for reflections and refractions.
Reflection Override Comparison Animation
Caustics can be difficult to compute, especially when using path tracing. But in many cases, water or glass look plausible even without caustics, window glass panels being prime examples. Because of this, we have decided to disable caustics by default. This significantly reduces render times, and if caustics are needed they can easily be enabled with the “Caustics” checkbox in Corona material.
Corona implements its own shadow catcher (matte/shadow) solution. It is a single material with all the necessary controls in one place – there is no need to combine special materials with other special texmaps. It works especially well with our interactive rendering for rapid camera and illumination matching. Advanced features, such as light illuminators and matte bump mapping, are of course supported.
Rendering by Ludvik Koutny
Speed is an important factor in production that cannot be ignored. A usable renderer must always deliver results as fast as possible. That is why we are always looking for ways to cut down parsing and rendering times, without forcing users to buy expensive hardware.
Rendering by Ramunas Gerulskis
In fact, we are obsessed with speed and we like to hunt for milliseconds in our own code. Corona Renderer also proudly uses Intel Embree Ray Tracing Kernels, making the CPU-only Corona as fast as many GPU renderers – but without the memory and flexibility limitations.
Corona Renderer 1.5 is significantly faster than any previously released version in the Alpha stage. And we have the numbers to prove it:
Forget the long delays before starting the rendering of geometry-heavy scenes. The whole process has been multi-threaded and otherwise improved. We have measured up to 12 times shorter preprocessing times.
Displacement is now also precomputed using all available CPU cores. This speeds up the process by about 450% on typical Intel i7 CPUs.
Scenes with many geometry instances will render faster after reworking the internal instancing engine. We were able to get speedups of up to 50% in some extreme instancing examples.
We have already reduced the delay after rendering large images in Alpha v7, but now we have found a way to speed them up by an additional 50% on top of the previous improvement.
We have found a simple tweak that speeds up the entire rendering when using GI caching, from 5% to 15%.
We have found and fixed a bug that sometimes caused an excessive displacement processing time. It is hard to determine the exact speed-up as sometimes the impact is negligible, but sometimes the render now starts up to 20 times faster.
The light sampling was improved considerably in Corona Renderer 1.5. This is a huge improvement especially in scenes with lots of directional/IES lights – but even scenes with simple diffuse lights benefit from this improvement. We estimate that a typical scene renders 25% faster on average.
Corona Renderer brings you state of the art, fully-featured interactive rendering.
Rendering by Andrey Minakov
You can change materials, lights, and create or adjust geometry while rendering. There is no need to manually restart or update the rendering, as it happens automatically usually within less than a second. It runs completely on the CPU, so it has no limitations and does not require any special hardware.
Rendering by Victor Naumik
Our interactive rendering is an integral part of the Corona core. In fact, it 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 with the non-interactive version. You can render motion blur, DOF, create proxies, scatter systems and more, all with instant feedback.
Rendering by Denis Jitnik
Because our interactive and regular renderer are almost identical, all types of geometry and proxies are supported. The same goes for all the 3ds Max maps and third party maps. Even the advanced third party plugins such as Itoo Forest Pack work as expected. You can find a full list of supported plugins in the Resources section.
Rendering by Dmitry Grankin
Our design goal for Corona materials is to make them physically based, yet intuitive, flexible, and easy to set up, without having to tweak unnecessary sampling values or other confusing parameters.
Rendering by Chakib Rabia
Material preview uses the same rendering engine as the final frame rendering. The default 3ds Max material preview scene is replaced with a custom, more representative Corona scene, to get the real “What You See Is What You Get” material editor.
Rendering by Ludvik Koutny
Corona Renderer uses the GGX microfacet model to deliver realistically looking metals and other glossy materials. This model produces much more plausible results than legacy models such as Blinn, Phong, or Ward. Because of our state of the art implementation, using this model does not incur any speed penalty which is usually present in other microfacet models.
Rendering by Victor Naumik
Our resources section contains some high quality materials from well-known artists and companies. The free to use materials are a great way to get started in your Corona endeavors.
The whole process of creating lights is designed to give artists complete control over their scene, while being fast and intuitive. There are no sampling multipliers, no differences between using light objects and materials, and no need to create artificial fill or dome lights. You can use HDRI, IES files, Sun & Sky system, 3ds Max lights, Corona Lights, or you can turn any mesh object into light simply by assigning to it the Corona Light Material.
Rendering by Maxim Kagirov
There are no sampling parameters that you would have to set by trial and error. Lights will always work as expected.
There is no difference in behavior of Corona Lights and Corona Light Material. Both of them have almost the same options and deliver the same results. So it is up to the artist to use what is more convenient.
In Corona, there is very little penalization for using mesh lights with high polycount. They will perform as well as low-poly ones with the same shape. Additionally, the version 1.5 improves sampling of directional/IES lights. They now render almost as fast as regular diffuse lights. You can see the improvement in this comparison with the older A6 version:
You do not need to set up any dome light object for HDR image-based rendering. Just put your HDRI into a 3ds Max environment and you are done. There is also no need to put downsampled/blurred versions of the map into a GI override slot – HDRIs in Corona work always fast and without splotches, regardless of resolution or complexity.
CoronaSky & HDRI Map, Equal Rendering Time Animation
Corona Renderer was the first production render engine that implemented the most accurate sky system available today – HoL?ek-Wilkie sky. It is currently selected as default whenever sun/sky is used.
SSS and Volumetrics
Corona Renderer also offers the volumetric/SSS rendering option in the version 1.5. We call it the Subsurface scattering revolution (SSSR). Why revolution? Because it is a fast, fully ray traced solution without any interpolation, and its UI is extremely simple.
Historically, there were many algorithms for volumetric rendering, most of which relied on interpolation, fakes, and heavy bias to compute the result. Fortunately with the modern fast CPUs and our research, we have been able to ditch all of these outdated options and go straight for the most accurate, 100% ray traced solution. Even we were surprised by how fast the unbiased, un-interpolated solution could be.
Rendering by Ramunas Gerlskis
Setting up volumetric scattering or SSS can be especially challenging. Fortunately Corona’s implementation comes with zero sampling controls, all sampling is done automatically. This makes its UI extremely simple: just set up the scattering and absorption properties of the material and press “Render”.
Proudly CPU Based
Corona Renderer does not need any special hardware to run. It uses the CPU and you can run it on any processor from Intel or AMD released in the past decade.
Rendering by Eduardo Diez Viñuela
By rendering only on the CPU we avoid all bottlenecks, problems, and limitations of GPU rendering. These include high cost, heat, and noise of GPUs, limited memory, limited shading complexity, limited support for third party plugins and 3ds Max maps, driver problems, and slower development. CPU shaders are faster to write, can utilize tens of gigabytes of memory, and can run on any hardware.
The only proposed advantage of GPU rendering is the speed. But how much faster are GPUs, really? The often mentioned “100 times faster” claim is a myth. According to a recent SIGGRAPH paper, CPUs and GPUs have roughly the same per-$ and per-Watt performance in non-trivial scenes. Empirical evidence from comparing various CPU and GPU renderers also supports this.
As of now, switching to current GPUs is just not worth losing the CPU flexibility and memory. We are however on the lookout for any upcoming technologies – CPUs, GPUs, and other coprocessors.
Corona Renderer uses the Intel Embree ray tracing kernels, the fastest CPU ray tracing primitives on the market. Since they mesh well with the Corona architecture, they are an important factor in its performance.
Traditionally, users had to choose to either use unbiased algorithms without any caching and wait long time for all renders, or use biased caching algorithms, and deal with splotches, missing shadows, and sensitive input parameters. Corona merges the best of both worlds. Its cached solution, called “UHD cache”, is significantly faster than plain path tracing, but does not suffer from artifacts, missing contact shadows, or complicated UI controls.
Rendering by Mohammadreza Mohseni
UHD cache uses only partial caching, and does not try to interpolate everything. While this is slower than fully cached solution (such as irradiance caching), it does not create artifacts, only noise that eventually goes away.
Rendering by Denis Jitnik
The biggest difference between UHD cache (released in Corona 1.5) and its predecessor, the HD cache, is in the animations. UHD cache is much more accurate, so it significantly reduces flickering – even when light sources or geometry are moving. This is especially important when the cache cannot be precomputed.
Rendering by Damjan Minovski
Rendering with multiple computers at once is essential for any real production. Corona facilitates this in multiple ways. It has its own distributed rendering system, and it is compatible with the Backburner and Thinkbox’s Deadline render farm management systems. It is also supported on a number of commercial render farms.
Setting up Corona distributed rendering (DR) is easy. Just make sure all render nodes have Backburner and Corona DR server installed on them. Search process is automatic and Corona can search for render nodes during rendering – render nodes will connect and disconnect automatically, as you turn the computers on or off, without stopping the render!
As former CG artists, we know that the output quality and speed are not the only things that make a great renderer. That is why Corona comes with many “little” workflow tweaks, that will make your life much easier.
Rendering by Tadeusz Chmiel
Creating masks in Corona Renderer is an easy process. You can create monochromatic as well as RGB masks simply by specifying Object ID, Material ID or by directly picking objects in the scene. You can combine different selections as union or intersection.
Waiting through the final rendering just to discover that you forgot to set one mask can be very annoying. Usually you would have to create a copy of the scene, turn off lights and GI or set up material override to speed up the render, render again, and load back the original scene. But Corona has a better solution: you can simply set up the missing mask and press the "Render Only Elements" button. Corona Renderer will instantly render only the masks and other render elements without the costly beauty pass.
Corona Material can be made invisible to masks, while staying visible in the beauty pass. This is a very useful function, for example when you want to create masks for objects behind glass panels.
All color mapping in Corona can be done in real time, before, during, and even after rendering. Available controls modify exposure, add or remove overburns, tweak contrast, tint, or white balance. This gives the artists the much needed flexibility in exploring light and colour in their visuals during the creative phase. The most used controls are conveniently available right in the Corona frame buffer. Here are some examples:
Exposure: +0EV, +2EV, -3EV
White Balance: 4500K, 6500K, 8500K
Highlight Compression: 2, 5
Artists can use a realistic camera model which incorporates all the common parameters, such as f-stop, shutter speed, ISO, sensor width, and aperture shape (blades/custom). This allows closely matching live footage. Corona’s specialty is the ability to turn any camera in your scene into a “Corona Camera” with CoronaCameraMod. This way any camera can have the same features and options (ISO, f-stop, …), without the need to convert its object. This can be especially useful when working with older scenes from other render engines.
Corona Renderer comes with its own scatter system, Corona Scatter. It is an integral part of the Corona Renderer plugin for Autodesk 3ds Max, designed to give a complete solution for distributing millions of high-poly meshes or proxies across geometry surfaces. A typical use is the distribution of vegetation: grass, forests, etc.
Thanks to Corona Scatter you are able to create scenes with virtually unlimited number of objects or polygons, while enjoying the luxury of a low memory footprint and high performance. Despite still being in the early stages of development, it already contains advanced functions like distributing and scaling objects by a texture map, collision detection, etc.
At any point during the rendering process, you can save the contents of the frame buffer into a single .exr file. This includes all the rendering passes as well. You can then open another scene or even close the application, and later resume the original render right where you left of.
With one click you can enable the Autosave function, which will save the rendering progress every few minutes in an .exr file. So if your render or computer crashes, you have the latest progress saved. You can either use the .exr as it is, or resume the rendering from it.
Corona comes with a new proxy format .cproxy. The format is cross platform (you will be able to use it in Cinema4D, Maya, standalone, or in any other future platform). It uses compression, so it is small and fast to save, load, and to upload to renderfarms. Proxy models are always converted to millimeters and properly scaled when loading in scenes using different units. Older formats are still supported, and an automated solution is provided for batch-converting all existing proxies into the new format.
The proxy contains human-readable metadata at the beginning of each file, for example the name of the source object and its material, making them friendly to your pipeline:
Rendering in Corona does not block 3ds Max UI. This means you can check your render settings and other parameters while rendering.
The settings UI has tooltips for most parameters, activated automatically when you hover over the controls. There is also an automatically generated online GUI manual you can consult when you do not have 3ds Max opened
Windows Vista, 7, 8, 8.1 or newer
- Currently Microsoft Windows only
- Corona is x64-compatible only.
- 3ds Max version: Autodesk 3ds Max x64 version 2011-2017, Microsoft Windows (Vista, 7, 8, 8.1 or newer).
- Cinema 4D version: Maxon Cinema 4D R14, R15 or R16, Microsoft Windows (Vista, 7, 8, 8.1 or newer).
- Standalone: Microsoft Windows (Vista, 7, 8, 8.1 or newer).
- Corona Distributed rendering (available in 3ds Max only) requires Backburner on render nodes.
- Versions for Linux and Mac OS are planned.
- Corona Renderer currently supports x64 versions of 3ds Max 2011 – 2017.
- There are no plans of supporting older versions of 3ds Max.
Floating Render Nodes, 3ds Max
- Unlimited access to all major, monthly, and daily experimental builds
- Paid monthly, with option to pre-pay 1 year
- Cancel any time without any penalty
- Requires 64-bit 3ds Max 2011-2017
- One floating workstation license (works also as a render node) + 3, 5 or 10 floating render nodes