Doom running in Blender Video Sequence Editor timeline

Here's a video (click):

A modal blender operator that loads doom file, creates VSE timeline full of color strips (80 columns, 60 rows), listens to keyboard input for player control, renders doom frame and updates the VSE color strip colors to match the rendered result. Escape key finishes the operator.

I have no idea what I'm doing, so it is entirely possible that the operator is written in a completely nonsensical way!

All the Doom-specific heavy lifting is in render.py, written by Mark Dufour and is completely unrelated to Blender. It is just a tiny pure Python Doom loader/renderer. I took it from "Minimal DOOM WAD renderer" and made two small edits to avoid division by zero exceptions that I was getting.

Instructions

1. Download code of this repository.
2. Put doom1.wad next to vse_doom.blend file, can get it from doomwiki or other places.
3. Open vse_doom.blend file in Blender. The file is made with Blender 4.0, I have tested up to Blender 4.4.
4. Click "Run Script" atop of the script editor window.
5. This will create 80x60 color strips in the VSE timeline below, load E1M1 from doom1.wad and start a modal operator that reacts to arrow keys to move. Escape finishes the operator and returns to "normal blender".

Performance

This runs pretty slow (~3fps) currently (blender 4.1-4.4), due to various VSE shenanigans. Updating colors of almost 5000 color strips is slow, it turns out.

The pure-python Doom renderer, while perhaps written in not performant Python way, is not the slow part here. It takes about 7 milliseconds to render 80x60 frame. It takes almost 300 milliseconds to update the colors of all the VSE strips, in comparison. I will see if I can optimize it somehow!

In Blender 4.0 or earlier it runs even slower, because redrawing the VSE timeline with 5000 strips takes about 100 milliseconds; that is no longer slow in 4.1+ (1-2ms).

A blog post with more details: https://aras-p.info/blog/2025/01/17/Doom-in-Blender-VSE/

.blend file contents

The vse_doom.blend file itself contains pretty much nothing, except this text script block:

import bpy
import os
import sys

# add blend file folder to import path, so that we can use .py scripts next to the file
blen_dir = os.path.normpath(os.path.join(__file__, "..", ".."))
if blen_dir not in sys.path:
    sys.path.append(blen_dir)

# make sure to reload run_doom/render modules so we can do edits while blender is running
if "run_doom" in sys.modules:
    del sys.modules["run_doom"]
if "render" in sys.modules:
    del sys.modules["render"]

import run_doom

def register():    
    try:
        bpy.utils.register_class(run_doom.DoomOperator)
    except:
        pass # was already registered

def unregister():
    bpy.utils.unregister_class(run_doom.DoomOperator)

if __name__ == "__main__":
    register()
    bpy.ops.lol.doom_player('INVOKE_DEFAULT')