INTRODUCTION
Janus is a render management system designed to organise entities in LightWave, such as objects, lights, cameras, render settings, and plugins for multi-pass rendering over a ScreamerNet render farm or using mode 3.

Janus's main strength is that is highly configurable by the user, and supports a wide range of parameters that may be modified on a per-pass settings. Of note, plugin settings, whether they be 3rd-party or LightWave-bundled, may be modified per pass. Other 'data blocks' such as texture layers of Clip Maps, Displacement Maps, and Node Displacements may also be changed and replaced on a per-pass basis. A wide array of scene settings can be modified, from Render Globals parameters to Effects Panel parameters. Lights can be modified, not only in terms of exclusion, but also their basic properties such as light color, shadow type, projection image, and others. A light's Volumetric properties may also be overridden.

Janus's flexibility is due to its 'command-line' approach to render passes. And this enables new commands to be easily added in the future. The command-line approach, however, may initially intimidate users who want an artist-friendly system of managing passes. However, as it shall be demonstrated, Janus employed within its 'out-of-the-box' workflow is highly efficient and simple. But, still, the user must take time to understand some of its concepts that may be unfamiliar.

Meanwhile, its configurable structure is an advantage for users with particular ways of working. It reduces render-pass setup time significantly. One way Janus facilitates setup time is through its ability to reference user presets for settings, so that oft-used parameters are standardised. This also reduces user-related errors. Once the foundations of Janus is understood, the user will be able to leverage other tools that is specific to Janus, such as using parameter inheritance to propagate settings from one type to another.

All in all, you'd still have to try it in your own projects. The important thing is the way Janus can fit in your way of thinking and your current way of working.

Render Pass Terminologies
Render pass, render layers, and render buffers: these are sometimes used interchangeably in the world of render pass management. For the purposes of clarity I will use the term 'render pass' as a generic term that may mean both 'render layers' or 'render buffers'. 'Render pass' in Janus is essentially any kind of pass it outputs.

On the other hand, I will use the term 'render layers' to mean layers that are used to separate elements in a scene. This is from the standpoint of actual scene elements. Example: car layer, street layer, sky layer.

This is juxtaposed by my use of the term 'render buffers', which mean the various data images that may be used for that particular element. 'Render buffers' include things like specularity buffer (i.e. of car layer), raw color buffer (i.e. of sky layer), normals buffer (i.e. of car layer), etc.

I hope that clears things up.

Mac Version
Janus was largely developed on a PC platform and was tested only in the Mac recently. It was found not to run reliably at all. It is possible that the code may be rewritten in the future for the Mac platform.

Trial Version
If you are using a trial version of Janus, there are only some minor differences to the full version. The trial version is time-locked to 15 days, and you can only have one pre-defined definition file. Do not change this definition outside the Janus interface, because it will render it incompatible with Janus if done so.

How to proceed with this documentation
I recommend going through (in no particular order) the Interface Walkthough, Concept and The Group - Command Relationship sections to understand the basic principles and functions behind Janus. Then view some of the tutorials, which will give you a better idea of how things are done in Janus. The Commands in Detail section provide some reference and a way to get started on the gritty details of Janus. Groups in Detail explains the innerworkings of groups.