bmidi is a node-based MIDI animation system for Blender, built in Python.

Installing bmidi

bmidi is not available as a full Blender addon (for now), so creating a clone of this repository is necessary for usage.

1. Clone The Repo

Clone this repository into the desired folder with:

git clone https://github.com/Hydle-Research-Group/bmidi.git

2. Install The Python Requirements

Find the Blender Python executable by typing the following in the Blender console:

import sys
print(sys.executable)

Input the following into the terminal (ensure the current working directory is located in the repository root):

'<your blender python path>' -m pip install -r requirements.txt

You may have to ensure pip actually exists by first using:

'<your blender python path>' -m ensurepip

Then upgrade it with:

'<your blender python path>' -m pip install --upgrade pip

3. Run main.py

Create a new Blender project inside the root of this repository, and open the main.py file inside the "Script" tab. Run the file with Alt-P or use the run button located right next to the file name, launching bmidi's node editor.

Using bmidi's Node Editor

bmidi's node editor contains various node types to animate MIDI data.

• MIDI Data: the "root" node of the graph, containing the MIDI file and data.
• MIDI Data Filter: a node for filtering input MIDI data based on a specific note and channel.
• Frame Collection: a node for animating objects given the input MIDI data.
• Action Copier: a node for animating actions on objects given the input MIDI data.

MIDI Data Node

MIDI Data nodes contain a MIDI file and have an output for the parsed MIDI data. There are controls for generating object keyframes, including a "frame offset" input for offsetting the animation start.

Clicking "Generate Keyframes" will set the timeline to -1, reset the animation data for all specified objects, then generate the frames.

MIDI Data Filter Node

MIDI Data Filter nodes filter input MIDI data based on a specified note and channel, outputting the filtered data.

Frame Collection Node

Frame Collection nodes allow you to describe a set of frames that occur during certain triggers (e.g., when a note starts)

These frames act either on a specific object, or a target prefix, where target prefixes are in the format [prefix][note number]. For example, an object might be named Drum60, so it's prefix would be Drum and bmidi would append [note number] to the end.

Action Copier Node

Action Copier nodes allow you to select a specific action that is applied to an object every time a MIDI event occurs.

The action's f-curves (keyframes) are copied along the timeline so that when the MIDI note is played, the action is animated at that point.

Free & Open-Source

bmidi is 100% free with no drawbacks or limitations. There is no "premium" version; you get the latest and greatest, all licensed under the GPL-3.0.

All source code is public, to anyone. There is no "hidden mechanism" included in this repository; every reference and used factor exists completely and fully.