Fluid

• Create a cube and set it to physics → fluid → domain
• Create an object inside cube and set it to physics → fluid → fluid
• On domain click to physics → bake button

/lab/blender/fluid

bake.py

import bpy
import sys
from bpy.app.handlers import persistent
 
#@persistent
def do_bake():
    for scene in bpy.data.scenes:
        for object in scene.objects:
            for modifier in object.modifiers:
                if modifier.type == 'FLUID_SIMULATION':
                    if modifier.settings.type == 'DOMAIN':
                        bpy.ops.fluid.bake({'scene': scene, 'active_object': object})
                        break
 
 
 
#@persistent
def do_render_opengl():
    bpy.ops.render.opengl(animation=True, view_context=False)
    bpy.ops.wm.quit_blender()
 
 
print("BAKE")
do_bake()
print("RENDER")
do_render_opengl()

rm -fR /tmp/cache_fluid*
blender fluid.blend --background --python bake.py 

Now in /tmp there are *png photograms