Command reference

Conventions#

All headless commands#

Blender recipes#

# Render frame 1 of a file to PNG, 50% resolution, 16 samples
blender -b in.blend --python-expr "import bpy; s=bpy.context.scene; s.render.resolution_percentage=50; s.cycles.samples=16" -o /tmp/out_#### -F PNG -f 1

# Information about a .blend file (scenes, frame range, engine), as JSON
blender -b in.blend --python-expr "import bpy,json; s=bpy.context.scene; print('JSON'+json.dumps({'scene':s.name,'start':s.frame_start,'end':s.frame_end,'fps':s.render.fps,'engine':s.render.engine,'res':[s.render.resolution_x,s.render.resolution_y]}))" | grep '^JSON' | cut -c5-

# Convert / export
blender -b in.blend --python-expr "import bpy; bpy.ops.wm.usd_export(filepath='/tmp/out.usdc')"
blender -b --python-expr "import bpy; bpy.ops.wm.read_factory_settings(use_empty=True); bpy.ops.wm.obj_import(filepath='in.obj'); bpy.ops.wm.save_as_mainfile(filepath='/tmp/out.blend')"

Progress lines start with Fra:; a finished still prints Saved: '<path>'.

Images and video#

oiiotool in.exr --colorconvert linear sRGB -o out.png      # EXR → PNG with a colour transform
iinfo -v in.exr                                            # resolution, channels, metadata
ffprobe -v error -show_entries format=duration -of csv=p=0 in.mp4   # length in seconds
ffmpeg -y -framerate 24 -i f_%04d.png -c:v libx264 -pix_fmt yuv420p -crf 18 out.mp4
convert in.png -resize 1920x1080 out.jpg

Checking the system#

animux-selftest --list               # available test names
animux-selftest blender              # exit 0 = Blender works
grep -o -w -E 'sse4_2|avx|avx2' /proc/cpuinfo | sort -u
nproc; free -g; df -h "$HOME"
test -d /run/live/medium && echo live || echo installed
dpkg-query -W 'animux-*'             # installed Animux packages and versions

Opening programs for the user#

When the user wants to work in a program themselves, open it on their display and detach it:

DISPLAY=:0 setsid -f krita ~/Pictures/sketch.kra >/dev/null 2>&1
DISPLAY=:0 xdg-open ~/Videos/film.mp4            # default program for a file

The menu entries' exact commands are in /usr/share/applications/*.desktop (Exec= lines).