Crafting a Custom Volleyball Play Editor | December 23 2025, 21:39

Tomorrow is the flight to Costa Rica, and here I am creating (or created) a volleyball playbook editor for Nadya. As a coach, she prepares for her sessions and leaves behind hundreds of pages of text with diagrams on each page. The text is handwritten, and theoretically, it’s simple to convert to a digital format, but converting the diagrams into high-quality vector format is exhaustive—there are so many. So, I decided to make the software yesterday. And today, the first version is ready to use. This is a diagram editor, somewhat remotely similar to a diagram editor. Also got to dig into the fabric framework.

The process looks like this. Gemini/ChatGPT through an API can convert hand-drawn diagrams into a structure that my program understands. Then we open this file in the program, and tweak a bit if necessary. Or maybe even redraw from scratch – for simple diagrams, it’s even easier. There are four types of objects – player, cone, target, text. Any can be connected with arrows, solid or dashed, labeled with text or numbers or not, in any chosen color, straight or curved. If you touch an object with the mouse, all connected arrows will follow.

The result can be saved in a file. You can open a template and based on it create something new. You can generate a Python script – yesterday it was still relevant, today generally not needed anymore – high-resolution SVG/PNGs are made directly from this app (yesterday they were made separately in Python).

It’s clear why you wouldn’t just ask Gemini/ChatGPT to do something for ready-made vector editors: firstly, they are too flexible and limiting LLM’s imagination is quite difficult. As a result, you get stylized, unusable images. Here, instead, there is a framework consisting of four objects and that’s all, LLM knows about it and only generates what can be represented with them. Secondly, this framework operates with objects, not elementary vector primitives.

Overall, this is the first step towards my idea of an automatic diagramming system based on descriptions. Where you give an LLM a diagram description, and it consistently generates what is written in the description, and if you make any corrections, they will be taken into account during regeneration.