GIMP Motion: part 2 — complex animations

This is the second video to present GIMP Motion, our plug-in to create animations of professional quality in GIMP. As previously written, the code is pretty much work-in-progress, has its share of bugs and issues, and I am regularly reviewing some of the concepts as we experiment them on ZeMarmot. You are still welcome to play with the code, available on GIMP official source code repository under the same Free Software license (GPL v3 and over). Hopefully it will be at some point, not too far away, released with GIMP itself when I will deem it stable and good enough. The more funding (see in the end of the article for our crowdfunding links) we get, the faster it will happen.

Whereas the previous video was introducing “simple animations”, which are mostly animations where each layer is used as a different finale frame, this second video shows you how the plug-in handles animations where every frame can be composited from any number of layers. For instance a single layer for the background used throughout the whole animation, and separate layers for a character, other layers for a second character, and layers for other effects or objects (for instance the snow tracks in the example in the end of the video).

It also shows how we can “play” with the camera, for instance with a full cut larger than the scene where you “pan” while following the characters. In the end, we should be able to animate any effect (GEGL operations) as well. This could be to blur the background or foreground, adding light effects (lens flares for instance), or just artistic effects, even motion graphics…
All this is still very much work-in-progress.

One of the most difficult part is to find how to get the smoother experience. Rendering dozens of frames, each of these composited from several high resolution images and complex mathematical effects, takes time; yet one does not want to freeze the GUI, and the animation preview needs to be as smooth as possible as well. These are topics I worked on and experimented a lot too because these are some of the most painful aspect of working with Blender where we constantly had to render pieces of animation to see the real thing (the preview is terribly slow and we never found the right settings even with a good graphics card, 32GB of memory, a good processor, and SSD hard drives).
One of the results of my work in GIMP core should be to make libgimp finally thread-safe (my patch is still holding for review, yet it works very well for us already as you can see if you check out our branch). So it should be a very good step for all plug-ins, not only for animation only.
This allowed me to work more easily with multi-threading in my plug-in and I am pretty happy of the result so far (though I still plan a lot more work).

Another big workfield is to have a GUI as easy to use, yet powerful, as possible. We have so many issues with other software where the powerful options are just so complicated to use that we end up using them badly. That’s obviously a very difficult part (which is why it is so bad in so many software; I was not saying that’s because they are badly done: the solution is just never as easy as one can think of at first) and hopefully we will get something not too bad in the end. Aryeom is constantly reminding me and complaining of the bugs and GUI or experience issues in my software, so I have no other choices than do my best. 😉

You’ll note also that we work on very short animations. We actually only draw a single cut at a time in a given XCF file.  From GIMP Motion, we will then export images and will work on cut/scene transitions and other forms of compositing in another software (usually Blender VSE, but we hear a lot more good of Kdenlive lately, so we may give it a shot again; actually these 2 introduction videos were made in Kdenlive as a test). Since 2 cuts are a totally different viewpoint (per definition), there is not much interest on drawing them in the same file anyway. The other reasons is that GIMP is not made to work with thousands of high-definition layers. Even though GEGL allows GIMP to work on images bigger than memory size in theory, this may not be the best idea in practice, in particular if you want fast renders (some people tried and were not too happy, so I tested for debugging sake: that’s definitely not day-to-day workable). As long as GIMP core is made to work on images, it could be argued that it is acceptable. Maybe if animations were to make it to core one day, we could start thinking about how to be smarter on memory usage.
On the other hand, cuts are usually just a few seconds long which makes a single cut data pretty reasonable in memory. Also note that working and drawing animation films one cut at a time is a pretty standard workflow and makes complete sense (this is of course a whole different deal with live-action or 3D animation; I am really discussing the pure drawn animation style here), so this is actually not that huge of a deal for the time being.

To conclude, maybe you are wondering a bit about the term “cel animation”. Someday I guess I should explain more what was cel animation, also often called simply “traditional animation” and how our workflow is inspired by it. For now, just check Wikipedia, and you’ll see already how animation cels really fit well the concept of “layers” in GIMP. 🙂

Have a fun viewing!

ZeMarmot team

Reminder: my Free Software coding can be supported in
USD on Patreon or in EUR on Tipeee. The more we get
funding, the faster we will be able to have animation
capabilities in GIMP, along with a lot of other nice
features I work on in the same time. :-)