scripting, trackMatteType

[Scott G]

why the heck does
myadd02.blendingMode = blendingMode.ADD;
work, but
myadd02.trackMatteType = trackMatteType.ALPHA;
say that trackMatteType is undefined??

AAARRRGGGHHH!!!

[Scott G]

it works if you say
myadd02.trackMatteType = TrackMatteType.ALPHA;
instead of
myadd02.trackMatteType = trackMatteType.ALPHA;

notice how one uses a capital T?

but for blending modes, it works when they’re both lowercase.
that’s inconsistent!

can someone please explain why this inconsistency works and is necessary???????????????????????????????
completely non-intuitive.
ARGH.

[Jeff Almasol]

Hi Scott,

You need to use TrackMatteType.ALPHA (note the initial capital T), which should be how it’s listed in the doc.

Your blendingMode.ADD example doesn’t work for me (I get a “blendingMode is undefined” message). Maybe you have a blendingMode variable earlier in your script?

Jeff

[Scott G]

Hi Jeff,

Heh, I thought you only lurked on the AE Enhancers forum.

I think I’m going crazy, as I tried the blending mode one again with the lowercase and you’re right, it doesn’t work. Too many hours staring at the screen.

I see now it is listed with a capital in the script guide, I wasn’t paying attention to the 2nd column in the index of properties at the back of the guide, and in the main section of the guide I guess I wasn’t paying attention either.
I assumed that all the properties started with lowercase letters, and over the past few days I got used to typing all these firstword-lowercase names, it didn’t click with me that you had to use the captial when setting as opposed to the lowercase when referring to it.

sheepish,
scott.

[Jeff Almasol]

Scott,

Note that blendingMode and trackMatteType are attribute of the AVLayer object (accessed as .blendingMode and .trackMatteType from your layer variable), but BlendingMode.ADD and TrackMatteType.ALPHA are enumerated values that you either assign to these attributes or retrieve from them. Their names (TrackMatteType vs. trackMatteType) are similar, but their usage is not defined by whether it’s initially capitalized or not. The enumerated value could’ve just as easily been defined as myTrackMatteTypes.ALPHA, it’s just a similar name and initial cap syntax was used to make the association with the attribute that would use it.

Jeff