omino pixel blog

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!

(The parentheses in the post title mean that this post is essentially parenthetical.)

Arggh. Developing Pixel Bender kernels and plug-ins, my test files kept behaving erratically. Expression indexes were to blame. Each time I added or removed a parameter, the numbers all shift.

So you see, first enabling the expression produces effect("my_effect")(8). But it depends on the exact order of the parameters!

But effect("my_effect")("param 9") depends on the name.

I think I like the second one better, because I’m pretty good about nailing down my parameter names, but more likely to move them around order-wise.

(See?)

Early this month, we visited the San Jose Museum of Quilts and Textiles, featuring patterns and clothing by the Hawaiian designer Alfred Shaheen. Great stuff! Yeah, I have a closet full of Hawaiian shirts.

(Show show goes til August 8, worth visiting. On the first Friday of the month, many of the galleries on First Street in San Jose, CA are open late, definitely a nice night out.)

Since I adore repetition, and halftoning, I got to wondering if I could recreate some of the patterns programmatically. The “Omino Stamper” filter runs in After Effects and attempts to do this.

download ==> omino_stamp.pbk, an After Effects filter.

The idea is pretty simple: draw a “stamp image” in a pattern which can be affected by the source image. It’s a little bit like a particle effect, but more mechanical.

Here’s the controls and few examples, which look nothing like Hawaiian shirts.

A quick rundown:

• The pattern- settings adjust the stamping grid
• The stamp- settings adjust orientation and size of the stampimage image
• The stampOverlaps setting controls how many nearby stamps are computed for each pixel; slows down the render a bit but is necessary for closely-spaced stamping. (If you see missing corners and such, increase this setting. (Those of you familiar with Pixel Bender will immediately apprehend why this is so. 🙂
• The affectsStampSizeAmount, affectsStampColorAmount, and affectsStampRotationAmount settings control the halftoning features of the filter.

Here’s a basic stamp:

Next, we adjust the bricking a little, to make it less square-y:

And let the color of the underlying image affect the stamp color:

How about affect the rotation, instead of the color? Kinda wild:

Or back to basics, let the underlying image affect the stamping-size:

Here’s a festive little animation playing with the effect a bit, and does include a Tiki god or two.

download ==> omino_stamp.pbk, an After Effects filter.

Enjoy!