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Limitations of Render Nodes
There are a few important limitations to remember while setting up compositions and rendering over a network.
Time Stretching
Compositions using the Time Stretcher and Time Speed tools may encounter difficulties when rendered over the network. Speeding up or slowing down compositions and clips requires fetching multiple frames before and after the current frame that is being rendered, resulting in increased I/O to the file server. This may worsen bottlenecks over the network and lead to inefficient rendering. If the composition uses the Time Stretcher or Time Speed tools, make certain that the network is up to the load or pre-render that part of the composition before network rendering.
Linear Tools
Certain tools cannot be network rendered properly. Particle systems from third-party vendors, such as Genarts’s Smoke and Rain, and the Fusion Trails node cannot render properly over the network. These tools generally store the previously rendered result and use it as part of the next frame’s render, so every frame is dependent on the one rendered before it. This data is local to the tool, so these tools do not render correctly over a network.
Saving to Multi-Frame Formats
NOTE: The above does not apply to network rendered previews, which are previews created over the network that employ spooling to allow multi-frame formats to render successfully. Only final renders are affected by this limitation.
NOTE: The above does not apply to network rendered previews, which are previews created over the network that employ spooling to allow multi-frame formats to render successfully. Only final renders are affected by this limitation.
NOTE: The above does not apply to network rendered previews, which are previews created over the network that employ spooling to allow multi-frame formats to render successfully. Only final renders are affected by this limitation.
Multiple machines cannot render a single QuickTime file. Always render to separate sequential file formats like EXR, DPX, JPEG, and so on. Once the render is complete, a single workstation can load the image sequence in order and save to the desired compiled format.
Troubleshooting
There are some common pitfalls when rendering across a network. Virtually all problems with network rendering have to do with path names or plugins. Return to the “Preparing Compositions for Network Rendering” section in this chapter to review some of the essential setup requirements. Verify that all Render nodes can load the compositions and the media, and that all Render nodes have installed the plugins used in the composition.
If some difficulties persist, contact Blackmagic Design’s technical support using the support section on the Blackmagic Design website. Save a copy of the render.log file to send to technical support.