In a practical sense the only way that a curved edge made of pixels can appear to be smooth is to:
- Have the pixels so small that your eye can't discern the jagged edges (aliasing) or,
- Blur the edge so that your eye is fooled into thinking the edge is smooth
Computer monitors have a very short dot (pixel) pitch so that the type appears to be smooth. Use a CRT from 1990 and see how pleasing the type is to look at. But even todays very high resolution displays have built in antialiasing that smooths out the edge of the type.
Your question seems to be "Can AE export clean masks?" It sure can. The higher the bit depth the cleaner, but a clean matte does't mean no grey in the alpha channel. It means an edge that appears smooth. Even with the cleanest edges I'm always applying a form of Light Wrap to the image to smooth out and blend a layer into the background so that the composite is believable. Light does this. I'm looking outside at the sun filtering through my Laurel hedge and the edges of the leaves have a little of the blue from the sky around their edges. To make a believable composite you have to blur the edges and wrap pixels from the background on top of the foreground.
If you really want to clip a matte to an exact pixel value you can set that up easily with levels. The attached image from the comp window is of two identical circular masks on a white solid positioned at uneven pixel values (off by an whole pixel value by .5 in one direction and .8 in the other). I simply applied levels to the layer on the right and set the offset black to .5000000 and white to .500000001 to clip the edge of the mask to a very precise pixel value. Which one looks like a circle? Which is the cleaner mask? The one on the right is clipped to very small pixel value. Change the number of decimal places to 4 places and the matte will be different, so you might say that the mask on the right is more accurate than the one on the left. The problem is that the one on the right would not composite into a scene easily, so IMHO the one on the left, the one with the grey values in the edges, the one with the interpolated pixel values, is the cleaner matte.
I hope this helps.
I believe your example is exactly what I mean by "clean", the pixels go to one or the other vs. the interpolation between them, it's not visually smooth but there is a clear separation of values..
I can't verify the solution until I get a test case back but you're describing the issue perfectly...I don't even have AE so it's difficult for me to describe any specific steps to remote users, this should be enough info to straighten things out..
I'll probably flag this as the solution after I can verify the results, I was pretty sure that AE could do this with the right settings, it sounds like you know what I'm looking at..
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In addition to Rick's magnificent (as usual) explanation of the underpinnings of not only reality, but the digital replication of it, here are two examples of what the difference between a "draft" setting, and a "best" setting will yield. Both are circular masks drawn on a white solid.
> The artists I am working with state that After Effects is unable to export clean mask images. If this is true, my other options are to (a) pick some alternate format for shapes, load the shape data and rasterize it myself, or (b) get up to speed with the AE SDK and try to write an export filter.<
Welcome to the family.
I'm having a bit of trouble with this claim but not because of my competence or experience, simply from our anecdotal history around here.
Major houses use After Effects at 2k and 4k resolution and even IMAX to create totally invisible masking and effects.
Hi bogiesan, I have to admit I'm being a little facetious in my post, I was absolutely positive this could be done in AE but I don't have a copy (or access to s system with one) and I don't know how else to explain it to the guys I'm working with remotely..
I asked the artists to disable anti-aliasing and they said it "could not be done", so I figured I would take them literally at their word and bring it up on the AE forums, I'm glad I did..
I'm still waiting on a test case to verify so I can mark this as solved, the test renders from TimeRemapper and Rick Gerard demonstrate exactly what I was looking for so I expect it will work for what I need..