Network rendering

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Whether you are rendering with LightWave Screamernet, ButterflyNetRender, another render manager or on an online renderfarm like GarageFarm.NET or REBUSFARM you should follow certain guidelines to make sure your final frames will come out like you want them to.

This tutorial will not go in depth on how to setup specific render farm software. However it should give you enough information to prevent most common errors that arise during network rendering.

Preparing Scene

Since LightWave scene contains many information about objects used in scene, images, plugins and related files, it is very important that you keep your files in such a place, that all network machines will be able to access them. Most problems in network rendering arise because some data can not be found from the network rendering machine.

Collect all files

Before you send your scene to the render farm you should check the following things:

  • Use Package Scene, Content manager or some other plugin to collect all scene related files into a single folder. If you are using .pfx or .mdd data you will probably need to move those by hand into the scene folder. You can open your .lws file in a text editor and check for any wrong paths.
  • Check if your scene is using any 3rd party plugins. The render farm machines will need to have the same plugins installed.
  • Make sure your network farm computers have read and write permission on the scene folder.

Choosing render mode

Which render mode you are going to use depends on the scene.

  • When using Raytrace mode there are no special requirements for the network rendering.
  • When using Photon mapping or Photon estimate mode special preparation is needed. If you have no moving items in the scene except the camera you should use Shared For All Frames. If there are moving lights or objects Interpolated mode is more appropriate. However Interpolated mode is not particularly farm friendly at the moment so we do not recommend using it on render farm. Independent mode can be used also but will most likely produce flickering between frames.
  • Path tracing can also be used on farm. It does not use photon maps so there is one thing less to worry about. If you are using Cached Irradiance then you should first make a preredner pass. If you are not using Cached Irradiance then you don't need to do the prerender pass.

Shared For All Frames

This mode is appropriate for scene with no moving lights or objects. The indirect shadows will be cached in this mode, meaning they will be computed only for the first frame and then reused for all subsequent frames. However you can allow your objects to move even in this mode if you really want by checking Allow animation checkbox.

Prerender pass

Rendering in Shared For All Frames mode requires you to make a prerender pass to cache GI data before doing the final rendering of frames. Creating prerender pass:

  1. Change Shared For All Frames mode to Update and specify a file name for GI Cache file.
  2. Save your Kray rendering settings so you can reload them later.
  3. Set frame range in Lightwave Render Globals. Set frame step to around 10. If you have fast moving camera you may need to decrease this number, if your camera is realy slow you may want to increase it.
  4. Turn Antialiasing to None on Sampling tab. On Quality tab set Reflection/Refraction Quality rays to some low number like 10/50. This is purely just to increase rendering speed of the prerender pass.
  5. On FG tab Passes must be set to 1. Otherwise your render times will grow with each frame.
  6. back in general tab select "Bake only" checkbox so Kray will skip final render pass because we don't need it for baking GI. Also uncheck file output.
  7. Render the whole sequence. This will generate the Cache GI file for the entire animation.
  8. Reload your original render settings and set the Shared For All Frames mode to Load. Make sure the path specified for the Cache GI file can be accessed by all the network rendering machines!

Rendering on Render Farm

You can render with Kray on two popular render farms:

GarageFarm is highly recomended. It's not the largest out there but you get excellent support and it's very cheap.

Rebusfarm is an online render farm service that allows you to quickly render your frames. To make sure your rendered frames come back like you want follow this guidelines:

  • Collect all scene files in one folder as described above. Also check if you are using any 3rd party plugins. The easiest way to do this is by making a separate LightWave installation that does not include any 3rd party plugins. Open the scene there and it should warn you if it finds any plugin that is not installed.
  • create prerender pass like described above.
  • Send your files to render farm as per their instructions and you are done!

Rendering on Butterfly NetRender

For now a short but important tip: BNR has per default a checkmark at "Remove Masterplugins" made mainly to strip the LWS from masterplugins like Spreadsheet Editor which can crash LWSN.exe in certain cases. This will remove our beloved kray plugins too...

  • Options/Configure/Configure Platforms, that should bring you to the "LightWave Windows Setup..." tab and then right column at the top.
  • Uncheck it and remove unnecesary masterplugins manually if needed.

We asked Paul Lord for an option to exclude kray from this default switch in future BNR versions.