One of the questions that comes up over and over again when we talk to software authors about licence choice is: “what is each type of licence especially good for?” Personally, when discussing permissive licences I tend to point to the imperative of pushing an open data standard as a prototypical use case. Luckily for me, computer graphics industry giants (and competitors) Lucasfilm and Sony Pictures Imageworks have just released v1.0 of their 3d scene format Alembic to prove the point.
Anyone who has dabbled in 3d computer graphics, perhaps using the FOSS modeller and renderer Blender, will have noticed just how many competing object and scene description formats there are out there. While this is a minor inconvenience for amateurs like me, it becomes a massive and expensive problem for visual effects production houses and their clients. Complex animated objects and scenes created in one application have to be laboriously exported frame by frame and reconstructed in the target application, often requiring duplicated effort to complete the import. Alembic avoids this by allowing the compression and exportation and importation of entire complex animated sequences.
So for CG professionals there is a clear need for something like Alembic (the name is taken from the piece of chemistry glassware which distills products and delivers them to another container). However for the creators of the individual software packages the idea of a simple interchange format is not a high priority; after all, why should they make it easier for clients to use another company’s software? It’s natural, therefore, that it is the clients themselves who have produced the standard and software which ‘scratches this itch’. Indeed there’s a precedent in the same industry. Back in 2003 Industrial Light and Magic release OpenEXR, a data standard and implementing software that allowed the interchange of so-called ‘HDR’ images (images with a greater range of luminance than standard image formats can store). In eight years OpenEXR has become a widely-used standard. With any luck, Alembic will follow in its footsteps.