TVPaint is a proprietary, pixel-based, 2D cartoon animation drawing program. It has a .csv export format, specially to export the animation into other applications. CSV is a plain text spreadsheet format (=comma separated values). The exported files are: png pictures in a folder and an exposure sheet in a csv file. The animation is layered, and the pictures are randomly reusable on any frames.
My addon is an importer for this format, based on the "Images as planes" and the Gimp import addons . Each picture is an individual plane object with its own image texture. I used animated visibility and renderability: on picture changes, it switches off the old picture and switching on the new one. Additionally, since each picture is a separate object, there are no frozen picture problems in the 3D editor, like with the image sequence textures.
There are two main modes:
1: It creates Compositing nodes and puts each layer on separated render layers. Wit this solution, many blending modes are possible for the layers.
2: It creates everything on the same, current layer and emulates some layer blending modes through material and texture settings. In this mode the supported modes are: Color, Add and Screen, and also in Cycles, Multiply. But these are a kind of fake.