If you’ve left a comment on this blog in the past month or so, and you wondered why I didn’t approve it or respond, then you might be interested to know that our spam filter went rogue and started killing… well… everything.
I’m digging through the purported spam now, trying to find the legitimate comments and approve them and respond to them.
Richard Harrington and Marcus Geduld have just released a new book about my favorite application and… well… that other one. You see, I’m one of those people who knows After Effects backwards and forwards but has had a hard time making the crossover to Flash. I’m pretty sure that there are a lot of people in the reverse position. (Actually, I know that there are, because I’m constantly correcting people when they use words like ‘stage’ when talking about After Effects.)
Richard and Marcus have come to the rescue.
The first two chapters of their book are designed for people like me. (Well, one is designed for people like me; the other is designed for my evil Flash twin.) One teaches the basics of Flash in terms that an After Effects user can understand, and the other teaches the basics of After Effects in terms that a Flash user can understand.
The good folks at Peachpit Press have made these two chapters available on their website:
The rest of the book goes on to explain how you do creative and production work in each of these applications and then move the pieces and outputs back and forth to get the best of both. But you have to buy the book to get those parts. I’m pretty sure that many of you will do just that as soon as you see the value in the introductory chapters.
Thank you, Richard and Marcus, for creating a two-way information bridge between these two applications.
Of course, there’s a section in After Effects Help (and in Flash Help) about working with After Effects and Flash. Richard and Marcus just did a more understandable and thorough job than we did.
I think that we do a solid job with the reference material for rendering and exporting to SWF, FLV, F4V, and XFL for Flash and Flash Player in After Effects Help, so I’m not too embarrassed.
Someone just asked on a forum why expanding a rectangular mask resulted in a mask with rounded corners. I made a little visual aid to answer the question, so I thought that I should post it here.
Increasing mask expansion is not the same thing scaling a mask. Scaling preserves shape. Expansion extends the influence of the mask by growing outward from each point along the mask path by a certain number of pixels.
For each point on the original mask path, imagine a circle radiating outward by the number of pixels by which you’re expanding.
In the image above, the white rectangle is the original mask path. The red circles indicate the expansion radius. Note how these circles define a sharp inner rectangle, which is what you get with a negative expansion; and they define a rounded outer rectangle, which is what you get with a positive expansion.
[Today's post is from Tim Kurkoski, After Effects quality engineer.]
When you render and export an FLV file with an alpha channel and then import the FLV file into Adobe Flash Professional (the Flash authoring application), you may get a colored halo in semi-transparent areas of the image if the background color of your After Effects composition is not black.
To work around this problem, do either of the following and re-render the FLV file:
* Change the background color of your composition to black.
* Change the Color setting to Straight in the Video Settings section of the Output Module Settings dialog box.
This problem occurs because the FLV encoder (the Adobe Media Encoder) only embeds alpha channels as premultiplied with black. The encoding happens after After Effects renders each frame and passes it on to the Adobe Media Encoder, according to the output module settings. This means that if After Effects rendered a frame as premultiplied and the background color was not black, then the background color will become embedded in the visible pixels of the frame.
Adobe Flash Professional and Flash Player only support alpha channels that are premultiplied with black. This is faster and simpler for Flash Player to decode than straight alpha channels. Flash Professional does not have a function to control how alpha channel colors are interpreted.
It is safe to use the straight alpha mode in the output module settings because straight mode does not embed the background color into the pixels. Thus there is no color contamination when the FLV encoder converts the alpha to premultiplied with black. However, the default Color setting is Premultiplied (with the composition background color), so you must change this setting manually every time. If you use this setting frequently you can create a new output module template.
Note: Earlier versions of After Effects have the opposite problem: black as the background color will cause a black halo, while other premultiplied colors may appear OK in Flash. FLV encoding in After Effects CS4 was changed so the default options (black background and premultiplied alpha) will produce a good-looking image. For any version of After Effects, choosing straight alpha will produce a good-looking image.