CGTalk - Weird problem with alpha channel

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phoenixart

07-15-2003, 11:36 AM

Hi guys!
a lot of time from my last post here ... sorry, very busy.
Here's the problem.

I'm creating a classic animation about objects into 3D grid space, with a camera movement as well.
So far I've 4 flat planes and 4 shaders applied to them: btw, the shaders have a movie into the color channel and alpha map to give to the planes a more subtle borders.
The weird problem is that when the planes intersects the grid, a "mezzotint" effect appears right near to the borders of the planes.

I've tried with a SLA gradient shader as alpha channel and with a Photoshop map, but the problem is still here.
And nothing happenings if I use Cubes instead of Planes.

Here's two examples:
(direct link)
http://f1.pg.briefcase.yahoo.com/bc/pdesopo/lst?.dir=/My+Documents&.order=&.view=l&.src=bc&.done=http%3a//f1.pg.briefcase.yahoo.com/

(if direct link doesn't works)
http://briefcase.yahoo.com/pdesopo

(Into "My Documents")

Any idea?

phoenixart

07-16-2003, 07:45 AM

No one?

tcastudios

07-16-2003, 06:44 PM

I´m not shure if I fully understand your problem but have you tried other AntiAlias settings? As far as I know , only the Best/Still setting makes all problems disapear regarding objects using alfa.

Lennart

Per-Anders

07-16-2003, 08:44 PM

you can't look into your documents folder on yahoo without a password. it's just a way of storing stuff for yourself.

instead use geocities or tripod or some other free webhosting (best if you can find one that allows hotlinking of images) then we could see what the trouble is.

JIII

07-16-2003, 08:53 PM

maybe post a scene file too man.

That can always help.

phoenixart

07-30-2003, 04:58 PM

Many apologies guys for this long-long delay: away from the web in these days ...

Ok, finally I've uploaded two sample images on my web site:
http://phoenixart.com/pub/alpha.jpg
http://phoenixart.com/pub/alpha_strokes.jpg

JIII

07-30-2003, 05:42 PM

hmm looks like a calssic geometry only anti alising.

If your settings are on best rather than geometry, then we have a problem.

AdamT

07-30-2003, 05:44 PM

I'm still not sure what it is you're highlighting.

phoenixart

07-31-2003, 08:11 AM

Here's the anti alias settings:
http://phoenixart.com/pub/anti_alias.gif

@AdamT: I'm highlighting the areas where Cinema render weird dotted lines, and they should be straight lines (just like others lines those are outside the red highlighted areas).

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