When you upload a piece of content to our servers, we run a variety of processes on it before building the final export packages. We build one package per platform (e.g. one for WebGL, one for standalone, one for each mobile OS, one for each console.) This processing does take some time to perform depending on the content type. Regions typically take around 15 minutes to process depending on their size (a large multi-gigabyte region can take up to an hour), whereas virtual goods (such as Clothing, Gestures or Vehicles) less than 5mb will process usually within 20 seconds.
When you upload content for processing it, we will process it in the order it is received, with a handful of exceptions. Virtual Goods less than 10mb in size will always process on a separate priority queue regardless of account status (this is to ensure you can quickly preview content that does not take long to process).
Other content will process on the larger region queue. We have a separate priority region queue for customers subscribing to a large region plan. Generally speaking we do aim for content to process quickly; during periods of large user growth, we may need to add additional processing servers
What happens to your content
Depending on the platform your textures are likely to be re-compressed into a native format for that platform, e.g. DXT1/5 on Standalone, JPEG for WebGL, etc. you can configure these settings prior to upload in the 'Importer'. We recommend against picking a specific format, and instead using the 'Automatic True Colour / Automatic Compressed / Automatic Crunched / Automatic 16-bit' master options; as specific formats may be substituted on a platform by platform basis.
Models & Meshes
We will strip mesh data down into a compact binary format. The specific format varies platform to platform (such as using 16-bit precision on mobile, and 32bit on desktop). Included animations will be often converted into rotational space, and re-sequenced onto a series of timelines. We may also strip data which is not being used by your materials (e.g. Vertex Colours or UV3/4 if your shaders do not require them.)
From time to time, we make make changes to our packaging formats, either to introduce new compression schemes or allow for new features to be supported. Often this will break compatibility with previous releases; so we have support for content reprocessing. When your content is published, we keep a copy of the original files uploaded to the processing server and can use these to automatically reprocess content into the newer formats. Generally this should not require any intervention on your part.