OctaneRender® is the state of the art GPU rendering engine, using the full visible light spectrum, instead of the more limiting RGB methods of rendering. This introductory topic serves to familiarize you with terms and components of the Octane environment, to help get you up to speed as quickly as possible. 


Introduction

C4DOctane is a plugin for Cinema 4D that allows unbiased, full visible spectrum renders to be created by Octane from within Cinema 4D itself. The plugin bridges the gap between Cinema 4D and Octane, allowing you to create in the environment you know (and love), using state of the art tools. Octane's GPU power offers a near real time viewer called Live Viewer to assist with scene setup, lighting and material creation and editing. You see your scene fully lit and shaded, in near real time, allowing you to create more quickly than ever before. at a level of quality rarely seen. Once satisfied with the results in Live Viewer, the scene is sent to the Picture Viewer for final rendering. What's more, Octane scales very well with multiple GPU support, better than any other rendering engine, so you can really put your cards to work for you. 


GPU Rendering Considerations

Octane is uses GPUs for almost every task, except for some file prep work to send scene data to the GPU. Most computers will have at least one GPU, though many will have multiple GPU cards. GPU VRAM is a precious resource: it is commandeered by the operating system and then doled out as the OS deems necessary, while reserving a fairly large chunk for itself. More and more applications and plugins are using the GPU resources, which means that those resources can come into conflict from time to time. Even browsers take GPU resources for every open tab. Knowing this, therefore, it is a good idea to shut down any unnecessary application or browser tab when you need the most attention possible from the GPUs in your system — typically this is when you are rendering final frames.


File Management with Octane and Cinema 4D

The C4DOctane plugin exists within the larger host Cinema 4D ecosystem. Octane uses bitmap files (TIFF, HDR, JPG) for Image Textures, and renders a variety of image file formats. The only way to import or add files into a Cinema 4D scene is to use the Cinema 4D file tools (Open, Merge, etc.) However, Octane provides its own tools to directly write render output files. 


The Cinema 4D file system can interfere with the process of file saving if the Cinema 4D Save options are enabled from the Render Settings panel. While it is natural to want to use these options, there are known issues in Cinema 4D that prevent the accurate saving of certain file types favored by Octane users. For this reason, you should only use the native Octane file saving options and disable the Cinema 4D save option. That said, you may need to enable portions of the options in the Cinema 4D Save panel, such as Alpha channel, in some cases. The Octane file save options are available in Render Settings > Octane Renderer > Main tab (for render attribute settings such as Motion Blur, Color Space, etc.) and Render Settings > Octane Renderer > Render AOV Group tab, where the actual file save paths and file formats are set and managed.


Remember to disable the Cinema 4D Save option in Render Settings along with the Multipass options (though the Multipass toggle will need to be enabled, as that is the only way that Octane can save multipass files. 

known issues with the Cinema 4D save options

The following list contains known issues with using the Cinema 4D save options for Octane renders. This list is collected from support tickets and forum complaints received over the years. It is not complete and may change as these issues are addressed in software revisions: 


      • Unintended/additional response curves
      • Incomplete/interrupted AI Denoiser output
      • Incomplete/corrupted EXR format output (typically multilayer files)
      • Issues with some EXR file compression options

Save with Octane File options instead

Use the Octane file saving tools directly as this will bypass the issues with the Cinema 4D save routines. Octane will directly save files to the disc without any Cinema 4D intervention as a result. This also applies to file output types such as EXR; Cinema 4D does not correctly write certain aspects of the EXR formats that Octane relies on, which is why the EXR(Octane) output option is available in the Render AOV Group tab.


Octane Breakdown

The following sections break down aspects of Octane, with links provided here to dive deep and get to where you need to go as quickly as possible. 


Rendering

Rendering is what Octane does: it takes your scene that you create in Cinema 4D, along with the Octane materials that you have created, the lighting you have set, and the cameras that you have chosen, and builds the final imagery using a technology called Spectral Rendering, which is far superior to standard RGB rendering used in most other products (including Cinema 4D). Spectral rendering uses the entire visible light spectrum to color each pixel as determined by lighting, material and camera contributions to that pixel, using all of the colors that human eyes are capable of seeing. By contrast, RGB engines must approximate the visible light spectrum using limited ranges, such as 16 or 32 bit color, which can actually eliminate or clip large amounts of color from the full visible spectrum color space — Octane does not have that disadvantage. 


Kernels

Octane offers several different, spectrally-based, unbiased core rendering algorithms, each one suited to different approaches. Which one you choose depends on your needs, along with how much time you have, as some algorithms can take longer than others. Octane packages these algorithms as kernels, which house all of the attributes needed by each particular algorithm, with many kernels having similar attributes. All of Octane's kernels are discussed here.


Near REal time previewing with Live Viewer

Live Viewer is the effective "command center" of Octane. It is in Live Viewer that you view material and lighting changes in near real time, access important Octane Settings (discussed here), and add Octane Materials, Lights and Cameras to the scene. Depending on your GPU setup, Live Viewer is fast enough to actually model under render scene lighting conditions in some cases, though make sure you save your scene before you do. It is important to note that Live Viewer cannot accurately show motion blur and other animation effects, as Live Viewer does not perform a full scene evaluation — Live Viewer is just a "snapshot." Only Picture Viewer renders go through a full scene evaluation. Read more about Live Viewer here.


Final Render/Picture Viewer Render

Once the scene meets your liking, its time for a final render. This is done by rendering to Picture Viewer, using the Render Settings discussed here. Rendering to Picture Viewer is the only way to validate your scene, visually, as all Picture Viewer renders go through a complete evaluation of the scene. Do not commit to animation renders without rendering test frames to Picture Viewer. 


Cameras

Octane cameras, like Octane lights, are actually Cinema 4D cameras with Octane tags applied that offer additional features specific to Octane. This tag is required in order to render from any camera in the scene. To learn all about cameras in Octane, go here.


Lights

Octane offers a variety of lights; many of these lights are based upon Cinema 4D lights, with Octane Light tags applied. Most Octane lights are "mesh lights," polygonal meshes with an Emission node applied. That is not true of the AI Lights; instead, these are parametric lights that are very efficient in terms of rendering. Octane lights are discussed in full here.


Octane Tags

Tags are used by Cinema 4D to extend object capabilities beyond the "out of the box" software experience. Tags can be used for selection of elements within objects, tracking, animating, and building associations between scene components. The C4DOctane plugin uses tags to add Octane functionality to Cameras, Lights and Objects:

Octane Camera tag

The Octane Camera tag is attached to any camera created from Live Viewer > Objects. You can manually add an Octane Camera tag to any camera object in the scene, just by going to the Object Manager, selecting the desired camera, and going to Object Manager > Tags > Extensions > C4DOctane tags > Octane Camera tag. This tag is required in order to render from any camera in the scene, and offers support for motion blur, depth of field, the AI Denoiser, and many other features. To learn all about cameras in Octane, go here.

Octane Light tag

The Octane Light tag, like the Octane Camera tag, is also attached to any light created from Live Viewer > Objects. You can also manually add an Octane Light tag to any light object in the scene, again by going to Object Manager > Tags > Extensions > C4DOctane tags > Octane Light tag. This tag is required in order to enable any Octane Light enhancements, such as color temperature, distribution, visibility and more. Octane lights are discussed in full here.

Octane Object tag

The Octane Object tag adds additional Octane features and attributes to any C4D polygonal or procedural object (note that some features may require the object to be converted to polygons.) As with the Camera and Light tags, Octane Object tags are added via Object Manager > Tags > Extensions > C4DOctane tags > Octane Object tag. The Octane Object tag is used to control material updates in Live Viewer or in final renders, motion blur, object visibility to cameras and shadows, and can replace the Subdivision generator in most cases with a GPU-optimized generator from Otoy. It is particularly important to use the Octane Object tag in animation, as it is needed a the top level of any object hierarchy that will be motion blurred, otherwise the motion blur will not be correct. Read more about the Octane Object tag here.


Materials and material components

Octane uses its own materials, as Octane materials contain additional information that Octane leverages to render spectrally. Cinema 4D's materials will not work with Octane, and should be removed from the scene before any final renders with Octane, as these materials can interefere with Octane's performance if they are present. C4D materials can be partially converted to Octane, but many of the more advanced C4D material features will not be converted (read more about that here). 


It's best to build Octane Materials from scratch, by starting with one of the many types of Octane Materials menu located in Live Viewer, or in the Octane menu found in the main menu bar of Cinema 4D. Octane materials make the scene, so spending time making them is worth the return on investment. For more information on materials, start here.


Textures

Materials need building blocks to create the best results, and textures are how to do this. Octane uses Image Texture nodes to load in bitmap textures, which is different than Cinema 4D materials. Octane has a "Bitmap Node" for compatibility purposes, but it should not be used. Instead, use the Image Texture node, available in both the Cinema 4D Material Editor and the Octane Node Editor. Octane also has a variety of procedural textures or generators, and supports OSL shaders (though these shaders may require modifications in some cases). Image Textures and procedural generators are discussed here.

Mediums

Mediums are non-empty volumes through which light passes, allow that light to be cirectly visible in the form of light rays and scattered light artefacts. Essentially particle clouds, these mediums can be used to add mood, provide ambiance, and so on. Common use of mediums would be to make the cone of a spotlight visible, or to add translucense to glass, for example. Octane offers several different takes on mediums, each with their own benefits. See more about mediums here.


Nodes and Node Editor

Materials can be built using the Cinema 4D Material Editor to a degree, but the custom Octane Node Editor is by far the better choice. The Node Editor contains all of the available parts to build incredible and efficient photorealistic or NPR (non-photo-realistic) materials to enhance any scene. The Node Editor is a drag and drop editing environment, literally drawing connections from one node to another as you build your materials. Nodes are the building blocks for Octane, as Octane is built directly on nodes. All components within the Octane universe are built from nodes, and assembled into node trees called "node graphs.". For more on the Node Editor, see here.


Node graph

While the Node Editor is used for editing Octane Materials, along with AOVs, lights and camera attributes, it is the Octane Node Graph that does the work behind the scenes. What you see in the Node Editor is a subset of the overall Octane Node Graph. Most of the time, you do not need to bother with this, but, if you're curious, you can see what the Node Graph looks like, and how to access it, here. The Node Graph is the heart of Octane Standalone, which is the basis of all Octane DCC plugins. Octane Standalone is used to verify any The Render Network job submission and is included along with your C4DOctane plugin, though you will need to download it separately from your OTOY customer account.


The Render Network

The Octane rendering service, The Render Network, offers a scalable online rendering service using a variety of operators over the world, utilizing GPU resources for rendering power. It is a token-based system, using concepts such as blockchain for transactions. The Render Network requires ORBX files to render. ORBX files can be output by the C4DOctane plug or by Octane Standalone.


ORBX

ORBX is the Octane object format that is used to render. The C4DOctane plugin with covert the scene file directly into ORBX format behind the scenes, but you can also directly write out the ORBX format from either Live Viewer or from Render Settings. ORBX is necessary for the The Render Network service.

Mograph

One of the great benefits of Cinema 4D is the Mograph system of cloners and modifiers for an amazing array of animation possibilities. Octane will work with most of the Mograph featureset, though it is best to "bake down" Mograph components before rendering animation, and definitely before submitting any jobs to The Render Network (as The Render Network cannot directly support Mograph). 

Dynamics and Simulations

Dynamics and simulations have come far, especially in recent versions of Cinema 4D. Any simulation needs to be cached before final rendering or submitting to The Render Network.

Volumetrics

Volumetrics are used to create and render smoke, clouds, and fire. Volumetrics use VDB files created with various simulation products, such as Embergen, Houdini and so on. In Cinema 4D, FumeFX, Turbulence FD and Cinema 4D's Pyro can be rendered directly in Octane, without the need to generate a VDB file, as long as the rendering is local. However, The Render Network requires VDB files. More on Octane volumetrics can be found here. 


Octane Standalone 

Octane Standalone is the original version of Octane. As the name suggests, Octane Standalone is NOT a plugin, but rather a free standing application, focuses solely on rendering. Octane Standalone is focused on the concept of a nodegraph, which is what drives the scene rendering. The user interface is minimal, but functional. While learning Octane Standalone is not a requirement, having those skills can help in some situations, particularly in debugging anomalies if they occur. Also, Octane Standalone can render more quickly than rendering via the C4DOctane plugin, as there is virtually no overhead involved when rendering with Octane Standalone.


Color Management

Color Management is used to process the original rendering output into a final form (or, perhaps an intermediate form for compositing). Cinema 4D and After Effects have both recently introduced the ACES/OCIO color management system, although Octane has supported this system for several versions now. Color Management is a complex topic, and much of the available research online is geared towards live action needs, which are far more complicated than the needs of computer rendering. Fortunately, color management in Octane is rather simple, though Cinema 4D does need to be properly configured to make it seamless. Configuring the Cinema 4D color management settings is discussed here and the overall Octane color management settings are discussed here.


Outputting Animation

Live Viewer is good for checking lighting and materials ONLY — the output of Live Viewer will often not be in sync with final renders to Picture Viewer in terms of motion, motion blur or changing procedural objects. This is because Live Viewer cheats to get real time. The output to Picture Viewer is the ONLY output that matters in the end, since that is your final render. Tools such as Make Preview can help to isolate motion issues. Do not use Live Viewer for this.


To prepare for final animation renders, bake everything down to remove procedural objects and operations (you need to do this to render in Octane Standalone and The Render Network as well). The reason is that you want to remove any potential issues that can happen with procedural objects when getting sent to Octane for rendering. By baking things down directly, any issues will become apparent BEFORE you commit to a final render. It's much less expensive to fix before you send.


AOVs, Cryptomatte and Z-Depth with compositing applications

In most cases, Octane is but a stop along the road of getting your work done. It is quite common to use compositing applications such as Adobe After Effects, Da Vinci by Black Magic or Nuke by The Foundry to assemble final shots together. For composite-heavy pipelines, AOVs (Arbitrary Output Variables) are commonly used. These AOVs allow for the isolation of  pixels in rendered frames for further operation, such as color enhancement, compositing and so on. 


Cryptomattes are uniquely-colored per pixel masks and can represent a variety of material and object characteristics, depending upon settings you choose. Octane can generate a variety of different cryptomattes, and they can also work with other AOVs. These masks can be used to isolate materials, backgrounds, objects and so on, with full transparency, reflections, refractions, and motion blur support. 


Another common output is the Z-Buffer, AKA Depth Buffer or Z-Depth pass, which is a 32bit per pixel grayscale representation of the depth of a given shot (you typically specify the beginning [black] and end [white] of the depth buffer range). Z-Depth passes are not anti-aliased by design, as the Z-Depth pass is a data representation about the depth of scene items within a range you specify. This pass is typically used for post-process depth of field effects. 


Getting to know more about Octane

There are numerous online sources of information regarding Octane outside of this documentation: this collection of Cinema 4D-specific links have a variety of additional topics to improve your Octane experience. Some of the linked articles also have video tutorials and presentations. Of course, there is also the Octane Forum, located here. This should be enough to get you started.