Scene file prep when using Arnold

The Arnold render engine has a common feature across the various plugin builds that causes render errors on render farms. Specifically, the setting that causes the problems is “Auto-convert Textures to TX”. This setting is present and editable in the render settings window of your render application.

The reason this setting causes problems on render farms is that it makes each render node attempt to convert textures and write them to .tx files for every single frame being rendered. When there are multiple render nodes that are trying to write to the same files at the same time, that is impossible, so only one of the render nodes “wins”. The rest “lose”, which causes Arnold to exit with an error code…typically an 0xC5 (access violation).

We recommend you disable this setting in your scene file prior to submitting it to Pixel Plow. If you wish to have Arnold convert textures to .tx files on your machine, and make use of the “Use Existing Tx Textures”, then you are welcome to do so.

Use of the Optix denoiser is not available for Arnold jobs because, at present, all Arnold jobs are scheduled on our CPU farm. The CPU farm does not have access to GPU’s, so any scene with denoising enabled will produce errors.

As a safeguard, we recommend enabling “Abort on license fail” in your Arnold render settings. While this shouldn’t be necessary, individual machines occasionally lose contact with their license server. It’s better for those machines to fail rendering a frame so our system can flag that machine as needing attention. If this setting is not enabled, and communication with the license server is lost, the frame will continue to render with watermarks.