This article was originally written by Nathan Willis on LWN.net. Thanks to him !
An unfortunate drawback to the scratch-your-own-itch development model on which many free software projects depend is that creators can lose interest. Without a maintainer, code gets stale and users are either stranded or simply jump ship to a competing project. If the community is lucky, new developers pick up where the old ones left off, and a project may be revived or even driven to entirely new levels of success. On the other hand, it is also possible for multiple people to start their own forks of the code base, which can muddy the waters in a hurry—as appears to be happening at the moment with the 2D animation tool Pencil. Plenty of people want to see it survive, which has resulted in a slew of individual forks.
Pencil, for those unfamiliar with it, is a “cell animation” application, which means that it implements old-fashioned animation drawn frame by frame (although obviously the software helps out considerably compared to literally drawing each frame from scratch). In contrast, the other popular open source animation tools Tupi and Synfig are vector-based, where motion comes from interpolating and transforming vector objects over a timeline. Despite its old-fashioned ambiance, though, Pencil has proven itself to be a popular tool, particularly for fast prototyping and storyboarding, even when the animator may create the final work in a vector application.
Original Pencil maintainer Pascal Naidon drifted away from the project by 2009. At that time, the latest release was version 0.4.4, but there were newer, unpackaged updates in the Subversion source repository. Version 0.4.4 eventually started showing signs of bit-rot, however, particularly as newer versions of the Qt framework (against which Pencil is built) came out. Users of the application, however, have continued to maintain a community on the official site’s discussion forum.
A box of forks
Understandably, there were never a ton of Pencil users, at least as compared to a general-purpose desktop application. But the dormant project picked up a dedicated follower when the Morevna Project, an open source anime movie project, adopted it for its workflow. Morevna’s Konstatin Dmitriev began packaging his own fork of Pencil in late 2009, based on the latest official Subversion code. He added keybindings for commands, command-line options to integrate Pencil with Morevna’s scripted rendering system, and fixed a number of bugs. Subsequently, he began adding new features as well, adding user-selectable frame rates, some new editing tools, and support for multiple-layer “onion skinning.” Onion skinning in animation is the UI technique of overlaying several (usually translucent) frames onto the current drawing, so the animator can visualize motion. But there are also a lot of bug fixes in the Morevna fork that deal with audio/video import and export, since the team uses Pencil to generate fill-in sequences for unfinished shots. Since Morevna is a Linux-based effort, only Linux packages are available, and they are still built against Qt 4.6.
In contrast, the Pencil2D fork started by Chris Share eschewed new features and focused squarely on fixing up the abandoned Subversion code for all three major desktop OSes. Share’s fork is hosted at SourceForge. One of the fixes he applied was updating the code for Qt 5, but that decision caused major problems when Qt 5 dropped support for pressure-sensitive Wacom pen tablets, which are a critical tool for animators. In early June 2013, Matt Chang started his own fork also at the Pencil2D site, using Qt 4.8.4. Whether Share’s fork hit a brick wall with the Qt 5 port or has simply stagnated for other reasons, Chang’s is still active, to the point where he has posted a roadmap on the Pencil2D forum and is taking feature suggestions. Chang has only released binaries for Windows, but he believes the code will run on Linux and OS X as well, and maintains it for all three.
Both of the forks at Pencil2D headed off on their own, rather than working with Dmitriev’s Morevna fork. More to the point, Chang’s roadmap includes a different set of drawing tools and a separate implementation of function keybindings. Luckily, the two forks’ editing tool additions do not conflict; Morevna’s adds a “duplicate this frame” button and adds controls for moving layers, while Chang’s include object transformations and canvas rotation.
In contrast to the other Pencil forks, the Institute for New Media Art Technology (Numediart) at the University of Mons took its fork in an entirely different direction as part of its “Eye-nimation” project. Eye-nimation is used to produce stop-motion animation. Numediart’s Thierry Ravet integrated support for importing images directly from a USB video camera into Pencil, where the images can be traced or otherwise edited. It uses the OpenCV library to grab live input from the camera, and adds image filters to reduce the input to black and white (bi-level, not grayscale) and smooth out pixelation artifacts. Ravet spoke about the project at Libre Graphics Meeting in April. The work is cross-platform, although it is built on top of an earlier release of the original Pencil code, 0.4.3.
As if three concurrent forks were not enough, many Linux distributions still package the final official release from the original project, 0.4.4. And there are several independent Pencil users who maintain their own builds of the unreleased Subversion code, some of which refer to it as version 0.5.
On the off chance that one might lose count, the total currently stands at five versions of Pencil: the final release from the original maintainer (0.4.4), the unreleased Subversion update, the Morevna fork, Chang’s Pencil2D fork, and Numediart’s Eye-nimation. The situation is a source of frustration for fans of the program, but how to resolve it is still quite up in the air. Dmitriev maintains the Morevna fork for utilitarian reasons (to get things done for Morevna); his preference is to work on Synfig and he does not have time to devote to maintaining Pencil in the long run, too. Chang does seem interested in working on Pencil and in maintaining his fork as open project that is accessible to outside contributors.
But combining the efforts could be a substantial headache. The Morevna fork is considerably further along, but Chang has already refactored his fork enough that merging the two (in either direction) would be non-trivial, to say the least. And it is not clear whether the Eye-nimation feature set is something that other Pencil users want; Dmitriev expressed some interest in it in his post-LGM blog report, though he was concerned that Numediart had not based its work on the Morevna fork.
The primary competition for Pencil is the prospect that cell-animation support will get added to another program. Krita has a Google Summer of Code (GSoC) student working on the feature (in addition to the partial support already added), while Dmitriev said in a private email that he hopes one day to implement cell-animation features in Synfig. If either effort bears fruit, that would be a positive development, but in the near term news of something like a GSoC project can sap energy from existing efforts, yet still might ultimately fall short.
It is a fairly common problem in the free software community for a well-liked project to fizzle out because the maintainers can no longer spend the time required to develop it and no one else steps up. It is rarer for multiple parties to independently take up the mantle and produce competing derivatives—especially in an obscure niche like traditional animation software. But when that does happen, the surplus energy, if it remains divided, can still end up doing little to revitalize a project that many users want to see make a return.