Warn About Missing Files When Performing an Animation Render.

I recently had an unfortunate incident where I started an expensive animation render on a project and didn’t notice that some image textures on a few objects had gone missing in the file. Only after reviewing the result of the aforementioned lengthy render session did I see the glorious pinkish-purple consequences of my mistake 🙂.

I feel like it might be fairly trivial to perform a check for missing files when a user starts an animation render — and then show some kind warning message if any are detected. At the very least, this behavior could be a configurable preference.