omino pixel blog

The Mac OS X version of Omino Python has been updated. An installer for it — and all my other After Effects plug-ins are in the downloads section here.

For anyone just tuning in, Omino Python is an After Effects plug-in that lets you write scripts to draw into a layer of an After Effects composition. It’s a lot like writing BASIC on your old Apple ][.

Changes to the plug-in are primarily:

• Fixed a sporadic crash that could happen during text rendering.
• No longer install any files in /opt/local or /usr/local. All gone.
• Completely unlocked (no license needed for full use). Enjoy!

Here’s a frame from one of the example animations. This is a couple of for-loops in action.

And here’s the animation it came from.

And here’s the python source code.

Edit: See note at end of article for warnings about this script AE CS 5.5 on Mac

Hello, pixel pushers and vert herders! Ah, it’s great to be back in After Effects land. Alas in this last year, the day job (got hired by Skype, acquired by Microsoft) and life in general (after throwing elaborate theme-parties for decades, planning a wedding wasn’t actually that hard, but still) got a little busy, but thankfully again have a little bit of time for my favorite things. That is, pixels.

Omino Python Since I released it this year, it’s been downloaded several thousand times, and about a dozen enthusiastic folks have licensed it. Alas, I don’t really have the time to either properly promote or properly support this as a paid product… so I’ll make it completely free soon.

Ok! So, MIDI!

What is MIDI

MIDI is a control protocol and file format invented 20-odd years ago for music playback on synthesizers. It records all the notes. A .mid file is typically quite small, since it has no sound data in it.

Into After Effects?

Yes! The attached script lets you read a MIDI file into After Effects, and provides keyframes with all the notes.

Install:

1. Download this file.
2. Put the file in /Applications/Adobe After Effects CS5/Scripts/ScriptUI Panels/
3. Run AE, and under window, choose om_midi.jsx, and dock the panel where you like.

Recipe

Here’s one way you could use this script. In the om_midi panel, click the little dot button, and choose a MIDI file. I used one from Wikipedia, BWV 772, one of JS Bach’s 2-part inventions.

Then, with a Comp selected, click Apply.

This creates a Null layer named “midi” with several Slider effects full of keyframes.

This particular MIDI file kept the left and right hands in separate channels, which is nice! The “pitch” effect has keyframes at the beginning of each note with a value of 60 for middle C, 61 for C-sharp, and so on. Here we can see the left and right hands’ keyframes.

A fun way to use these keyframes is to drive the Position property of another layer. I took a photo of my hand, and set the Position expression and Opacity expressions:

Position:
 transform.position + 5*(0,thisComp.layer("midi").effect("ch_0_pitch")("Slider")-60)

Opacity:
  transform.opacity * thisComp.layer("midi").effect("ch_0_vel")("Slider")

So the hand will move 5 pixels for each semitone, centered on Middle-C (60).
Then I rendered the audio as AIFF and added it to the comp. (I used Propellerheads Reason. Yeah… if you’re using MIDI you need yet another set of software to manipulate it.)

And here is the result animation:

More Notes

This is just the simplest usage. A more elaborate deployment might be to export just 1 part of a complex sound-track work as MIDI, to get some of the cues into your AE timeline. With more complex scripts or expressions, you could to much more than just move the hands around.

The script will put multiple keyframes with the same time-value! In the example above, you can see the hands flicker slightly as the final chord begins. Most of the the part invention has just 1 note per hand, which was nice for the demo.

Also, inside the script is a general-purpose MIDI file reader, which you could use for other purposes. I’ve generated Illustrator pictures from scores, for example, full of circles and triangles. Drop me an email or comment if you want help using it! It’s pretty fun.

Update 2012.01.08 Warning about AE CS 5.5 on Mac

Under Mac OS X AE CS 5.5, when you choose the file, it deletes it! This is a CS5.5 bug. (Works fine in CS5.)

Best workaround is to use AE CS 5 or AE CS 4.
Another workaround is:

• make a copy of the file, like myfile_copy.mid
• Select it in the script UI
• recopy the file (selecting it deleted it)
• click apply and all is well.

I was going to provide another example or two of Python scripting, today, but was sidetracked by a little bit of historical research on Python in After Effects. The examples will wait a little longer…

Useful Things

Yes, indeed, everything old is new again. Just about the time I started using After Effects, I had heard of “Useful Things”, but didn’t really know what it was. Turns out it was… Python Scripting for After Effects! It appears to have been quite well-regarded in the AE community, too. Alas, for whatever reasons, that product seems to have faded, been reabsorbed in the various business permutations that are a fact of life.

Omino Python for After Effects, by coincidence and parallel evolution, seems to resemble that fine product in some aspiring ways.

Grant Munsey

Going back even a tiny bit further, to 2001, we find that Adobe computer scientist Grant Munsey created open source Python bindings for Photoshop and After Effects, as well!

Reading about him, he was a great proponent of open source development, and was a driving force for establishing http://opensource.adobe.com/.

He passed away in 2005; I did not know him. But reading about his long illness, I was touched by this part of his wife’s account:

We’ve been using the mouth stick. It’s a 16-inch rod with a rubber tip on one end and on the other end a U-shaped plastic thing he bites on. He can then trace patterns and point to letters on the letter board — very slowly. I asked him what UNIX command you’d use for getting regular expressions from a text file, and he spelled “GREP”.

And forgive me if I find in this a dark justification for the oft-maligned brevity of UNIX commands.

For immediate download: Omino Python Plug-in for After Effects.

This plug-in lets you write a script in Python and then run it on every frame. The script can do drawing, access other layers, and so forth. Because sometimes, you just need to write code to get the job done. Omino Python gives you a straightforward way to provide drawing code directly in your After Effects work flow.

This isn’t for everyone; but if you have a little bit of scripting experience, Omino Python should be very easy for you to pick up.

Mac OS X on AECS5 only, for now…

Here’s a little demo.

Here’s another youtube demo, too.

The download includes plenty of documentation, or you can read it right now.

I’ll be posting some tips and examples — there are so many possibilities opened up! — but to break the ice, here’s a simple Omino Python script to do some drawing.

The script in Python. I didn’t know Python before starting the project, but it’s a nice easy little language, and quite popular, so there’s plenty of resources to learn it. It’s not so different from JavaScript or anything else. No semicolons and no curly braces, though! Here it is:

import math
import random

def ompy_main(c):
    ctx = c.layer_out_context

    w = int(c.width)
    h = int(c.height)

    # draw a red circle...
    ctx.set_source_rgb(1,0,0)
    ctx.arc(w/2,h/2,100,0,2 * math.pi)
    ctx.fill()

    # effect parameter controls size
    size = c.floats[0]
    ctx.set_font_size(size)

    # draw a grid of random numbers, spaced by 30
    random.seed(c.frame) # start the random sequence
    for x in range(0,w,30):
        for y in range(0,h,30):
            # random color
            ctx.set_source_rgb(random.random(),random.random(),random.random())
            # random number
            n = str(random.randint(0,9))
            # draw it.
            ctx.move_to(x,y)
            ctx.show_text(n)

And here’s a screen shot showing the output:

Your script can access a collection of parameters — some floats, some colors, &c — and use them as needed. In this case, I just used one float parameter to control the size of the random numbers printed.

This is just the beginning! Read the doc for the full story. Try out the plug-in.

More to come!