# Blender: render different periods of a sequence into different files

TL;DR: is it possible to render automatically frame X to frame Y into file first_part.mp4, and frame Y to frame Z into second_part.mp4? Ideally, I'd also love to be able to render via command line, using something like blender -b myfile.blend --part first_part to render a single part, and blende -b myfile.blend --all-parts to get both first_part.mp4 and second_part.mp4.

My use case: I'm trying to use blender to create animated slides for presentations. For example, my talk could look like:

<a girl is on the screen alone>
- Hello everybody, here is Alice
<I press a button, a boy appear on the screen>
- Here is Bob.
<I press again a button, and a box appears on the video, moving from Alice to Bob>
- See: Alice sends a message to Bob


On blender, I don't have any troubles to create a big animation, that shows Bob alone (say frames 1-5), then Alice arriving (frames 5-10), and then the box moving from Alice to Bob (frames 10-30). However, in order to pause the video at the right time, I'd much prefer having 3 differents video, and render them into different files. Of course I can manually render each one by putting some markers M and then manually render all the files, but when the number of "slides" become higher, it's really long to do manually, and error prone. So I'd love to have a way to name these parts, like:

• first_part = from frame 1 to marker "first part"
• second_part = start at marker "first part" and stops at marker "second part"
• third_part=starts at marker "second part" and stops at marker "third part")

That way I could ask to render one specific part, or all parts in one go. I'd also love to be able to use command line (see above) to specify which part I want to render, as it could be very practical if I want to redo the whole

Potentiel solutions: I guess I could write a python script, basing my idea on this answer, but it is a bit dirty I guess. Another option (thanks intrac) seems to use only the command line using something like blender my_scene.blend -f 1..50 -b, but not sure how to get the list of markers from the command line.