Workflow: Interactively run snippets of code (breakpoint, hot reloading)

[Splines]

I've just watched Grant's awesome How I animate 3Blue1Brown video and was fascinated by his effective workflows where he could run part of the code and immediately see the output in an interactive window. In the video, this is between 3:32 and 6:48, with the most important part starting at 5:29.

This workflow is described in his Readme here and relies on

• Manim having an interactive mode (which is different than rendering a video file and opening it).
• Sublime shortcuts that are state-aware and can interact with a terminal. E.g. Grant highlighted part of the code that had a comment on top. Apparently, the checkpoint_paste() method then looks for cached scene states (cached based on the comment) and renders the scene starting at that point. With the help of Sublime shortcuts, Grant is able to highlight code, press the key and immediately see the effects in an interactive window that even supports navigating the 3D scene. All of this kind of acts as a Python debugger breakpoint.

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When I first tried Manim community a few years ago, what annoyed me was that the turnaround time is too long in my opinion, especially when working with a bit more complex scenes than the examples. Always having to render out a video file is tedious. Looking at the Manim Getting Started guide again now, it still proposes to enter commands in the shell in order to render out video files to preview a scene.

That's why I'm asking if there is any more interactive workflow available with Manim Community? E.g. one like the presented in the video where an interactive 3D scene is always visible in a floating window. It would be really cool if this was even available in VSCode as I don't use Sublime. Maybe this would be something for manim-sideview @Rickaym if this kind of workflow doesn't already exist?

How do you work efficiently with the Manim Community edition? Could you share some of your tips?

[Rickaym]

Mhm, manim-sideview does have a similar workflow. It allows you to see the rendered output in realtime inside the VSCode window. The way it works is that, it is listening to vscode events and when the file is being saved or a custom shortcut is being stricken, the video is rendered and a webview is spawned in the editor. The underlying rendering command is the same command for rendering that we would usually do.

[uwezi]

The underlying rendering command is the same command for rendering that we would usually do.

...and therefore Manim Sideview is "as slow" as it would be rendering the same scene from the command line. But are you aware that you can use Section()s in ManimCE.
https://docs.manim.community/en/stable/tutorials/output_and_config.html#sections

I myself don't find the rendering times problematic, even when working on quite long scenes. I sometimes break out short snippets and try some quick layout changes on these short snippets, but in general from working with Manim I have got an innate understanding and feeling on how to place objects on the scene.
I am also writing almost all my texts using LaTeX and have done so for almost 30 years now - I find most GUIs very annoying because everything is hidden in menus under menus of menus and drop-down lists...

so everyone's mileage may vary...

[Splines]

While I greatly appreciate all the efforts for Manim Community Edition (Manim CE) & Manim Sideview and what it is already doing, the workflow still feels a lot more tedious compared to Grant's ways of doing things:

• With Manim CE & Manim Sideview, the scene is completely rendered before any output is shown. Compare that to Grant's workflow, where the scene is rendered "live" and you get to see the output immediately, no waiting time (depending on processor power of course). For example, see these few seconds of the video and look at the right side of the screen.
• With Manim CE & Manim Sideview, the output is a video file (that is rendered inside a webview in VSCode for example). With Grant's code the output is as well a video stream, but one that is interactive. He can place his cursor inside it and rotate around in the 3D scene (which I find very useful in other software even for 2D scenes to get a better sense of the spacing). See for example these few seconds of the video.
• With Manim CE & Manim Sideview, I can only preview the whole scene. Grant's workflow is more fine-grained: he can select some lines of code of a scene that starts with a comment and then start rendering at this particular part of the scene (all of this triggered by a single shortcut). This is especially useful when the scene is complex and shares lots of context and where it might not be worth it to split into several classes.
  I don't think it's an easy undertaking to get this partial scene rendering to work correctly as all the previous states of the scene have to be correctly inferred. But somehow Grant did manage to do it ;)

I was just wondering, as Manim CE is a spinoff off Grant's library, whether some similar functionality is already available for Manim CE to ease the process of creation where it's a lot of back and forth and adjusting parameters (like color, spacing, sizing etc.). Quick turnaround times would tremendously help there. In Blender I get all the interactivity, but then programming in Python is way harder over there as you don't get all the lovely functions and objects that Manim already comes packed with. On the other hand, Manim is feature-rich and eases automation and animation according to mathematical rules, but the interactivity is lacking for me. More interactivity would mean more fun during the creation since less time is spent waiting for some video to have finished rendering.

[behackl]

I would like to see, at the very least, a version of Grant's mechanism for previewing particular, short sections in a scene in the community version too, it is very handy. Our section-mechanism does, in principle, something similar; it is just that the interface is less agile (and that the current render loop still needs to process the entire scene, which is somewhat slow even if rendering is skipped).

It mainly is a question of resources; we have been working on a refactor of the render loop for ages, recently with some more progress on our experimental branch. But progress is slow, and people get busy with other things. Help to get things done is, of course, always welcome.

[Rickaym]

It would indeed be fantastic to see Grant's mechanism incorporated into Manim CE.

Thanks for pointing out the Section class, @uwezi - I didn't realize it before. The speed of Sideview does seem to be somewhat unusual, and it seems to be tied to the processes of VSCode, which can occasionally be a bit cumbersome. Much optimization remains to be done there. Ideally, we'd be able to see it function at the same level as Grant's GUI.

And I'd honestly love to contribute to Manim CE at heart, but unfortunately, it is a tough effort to spare time.

[VladimirFokow]

check out this new VSCode extension (it's specifically for 3b1b's manim version. Maybe it can be adapted to community?):
https://marketplace.visualstudio.com/items?itemName=bhoov.vscode-manim

extension's repo: https://github.com/bhoov/vscode-manim

update: the repo was renamed to: https://github.com/bhoov/manim-notebook

[VladimirFokow]

however I have a problem with this workflow - I don't have checkpoint_paste command defined at all..
Issue: 3b1b/videos#78

[Splines]

Did you use the latest version of manim that is available on pip? I don't think it has this command available. Instead, use the latest commit on the master branch. Clone the repo, then do pip install -e . inside it, see here.

[VladimirFokow]

ooh, thanks, will try!
upd: It worked!

[Splines]

don't forget to uninstall the version from "online-pip" beforehand: pip uninstall manimgl

[Rickaym]

Interesting. I'll see if I can implement something similar in sideview for CE/GL.