Gentlemen, my hat is off to you. Thanks for such a fast and helpful
response.
Adding in the Core Image Filter patch fixed the issue. Sidenote: I
was puzzled to note that when rendering my original Billboard-only
composition in Quartz Composer the same white fuzz did *not* appear on
my mask image. In other words, rendering the exact same composition
in Quartz Composer produced NO fuzz, while rendering it via QCRenderer
in my app produced fuzz. And I was careful to make sure it was pixel
aligned, real size, and no other transformations applied. A screen
capture confirmed that both rendered images were lining up pixel-for-
pixel in the final full screen layout, with the sole exception that
one had fuzz and the other didn't. Weird. But now fixed.
Thanks!
Chris
On Nov 11, 2008, at 2:33 AM, Chris Wood wrote:
What Christopher said, but also be aware of some of the things that
cause the image to get filtered in the first place.
The obvious one is scaling: if you render the image at a different
size to it's original, the graphics card with stretch it and do the
filtering. You can prevent that by setting the dimensions mode to
'real size', which forces the system to render it at exactly the
same size as the original image. That might not be what you want
though.
The other thing is pixel alignment - QC's units mean you can render
your billboard at positions that are 'between pixels', and that will
lead to fuzziness too. It took me ages to figure out that was what
was causing fuzziness in some of my work. You can prevent that by
ticking the 'pixel aligned' box on the billboard.
Chris
On 11 Nov 2008, at 03:20, Christopher Wright wrote:
When I feed the billboard an image with transparent pixels, it is
performing some kind of anti-aliasing which causes "white fuzz" to
appear where transparent pixels neighbor opaque pixels.
I'm not sure exactly what is responsible for the anti-aliasing, or
exactly what mechanism is being used to perform the anti-aliasing,
so I'm not sure how to turn it off.
That's called "Bilinear filtering" -- its the way the texture is
sampled. Not multisampling/antialiasing (though similar).
Check out /Developer/Examples/Quartz Composer/Compositions/Core
Image Filters/Nearest Neighbor Sampling.qtz -- that demonstrates
how to disable bilinear filtering inside the composition. This
should be what you're looking for.
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Quartzcomposer-dev mailing list ([email protected])
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/quartzcomposer-dev/archive%40mail-archive.com
This email sent to [EMAIL PROTECTED]
