Fix Ftrack Thumbnail Issue With ExtractLastVersionFiles

Understanding the Issue: Static Thumbnails in Ftrack

In the fast-paced world of animation and VFX, staying organized and getting a clear overview of your work is crucial. Ftrack is a fantastic tool for this, acting as a central hub for all your project's assets and progress. However, a recent issue has surfaced that can make this overview a bit blurry – literally. When using the "Reuse from Last Version" feature, particularly when publishing existing frames on a farm, the ftrack thumbnail can sometimes appear as a static image instead of the expected playable video. This can be a bit frustrating because while the actual review video works perfectly fine when you navigate to it directly within ftrack's web review, the visual cue – the thumbnail – isn't quite giving you the full picture at a glance. This article delves into why this happens and how we can fix it to ensure your ftrack thumbnails are as informative and dynamic as your work.

Imagine you're working on a complex animation sequence. You've rendered out a bunch of frames, but maybe there was a hiccup, and a few frames in the middle didn't get rendered. Instead of re-rendering everything, you use a handy feature called "Reuse from Last Version" to grab those missing frames from a previous iteration. This is a huge time-saver! The system is smart enough to understand that the full range of frames should be considered part of the current version. It updates the representation data, telling ftrack that frames, say, 1001 through 1100 are now part of this version, even if only 1001 and 1003 were newly rendered. But here's where the hiccup occurs: while the representation data gets updated correctly, the instance-level frame data doesn't. Downstream plugins, which are responsible for generating those helpful review videos and thumbnails, rely on this instance-level data. Because this data hasn't been updated to reflect the full frame range, the thumbnail generation process only sees the explicitly rendered frames (1001 and 1003 in our example). The result? Ftrack displays a static image, essentially a snapshot of just those few frames, rather than a smooth video showcasing the entire sequence. This disconnect between what the system knows about the full frame range and what the thumbnail generation process perceives leads to this static image problem, hindering our ability to quickly preview our work directly from the ftrack asset list.

The Technical Breakdown: How "Reuse from Last Version" Impacts Thumbnails

Let's dive a bit deeper into the technical specifics of what's happening behind the scenes when you use the "Reuse from Last Version" feature in Nuke, especially when leveraging farm rendering. The core of the issue lies in how Ayon (formerly OpenPype) manages frame data during the publishing process, particularly when dealing with gaps and reusing existing frames. When you opt to publish with "Use Existing Frames - Farm," the ExtractLastVersionFiles tool is invoked. Its primary job is to intelligently fill in any missing frames by copying them from a previous version. This is a fantastic workflow for efficiency, ensuring continuity without unnecessary re-renders. The tool correctly identifies the full range of frames that should be part of the current version – let's say frames 1001 to 1100. It then updates the `repre[