Antialiasing..?

[ycliao]

Hi! Everyone!
Well, I'm trying to render my character with Green background, and I want my character to be antialiased inside and no antialias in outside to easily take off that green background for later use.
Anyone knows about this?
Thanks in advance.

[fredc]

...You must have noticed the "halo" around your anti-aliased objects. Not to worry, your images already have an alpha channel. These are best suited for keying out the background. All 3D animation products create these.

To see the Alpha Channel, bring up an image in Photoshop and look at the last channel in the Channels page. This channel can be used to create your selection mask in Photoshop or for compositing in your editor.

Good Luck,
Urp

[jtk77]

Are you attempting to create sprites for a Director like app? If so ( since director still doesn't like alphas that much) the best way to pull off what you want is a little tedius if you have a large animation --but -- bring the pictures into photoshop and grab the image with the wand or selection with the antialias off then delete the antialias pixels leaving you with a sprite that has no (or less than) a halo on it when you bring it into the app . If I'm way off base with this please post I haven't messed with Director like stuff in a long time . I can't think of any other reason you would want your edges sharp and the inside smooth . It would be nice to have an option to turn off the antialiasing of the alpha channel and not the image , but so far I don't know of a way to do that ...except maybe rendering out the image with no alpha channel antialiased, then render out the alpha channel as a mask aliased . Load the two together in a program like After Effects , use the alpha seq. as its mask then render the two out together as one sequence . That may work for you to give crisp edges with a smooth image without doing it by hand . Post if I'm way off becouse now I want to try it out ....
Oh Urp , all 3d apps create alphas except for Brice 3D it seems ... in that odd "best buy " -ish package I think you have to render it out on a soild color to key out the image . I've seen people moving from that package to a real package and still trying to render out their images on solid colors ....Maybe thats what you're trying to do esn?

"Wow! How'd you do that! That looks like somthing out of a movie!"
--some guy at work .

"Wow! How'd you do that! That looks like somthing out of a movie!"
--some guy at work .

[fredc]

Current versions of Director do use Alphas.

However, if one does need to remove the "halo" manually from a single image- Photoshop does have a feature for this.
Layer/Matting/Defringe or Remove Black/White Matte.

Good Luck,
Urp

[jtk77]

yes but having EVERY sprite as 32 bit in director is a MAJOR bottle neck and almost not even worth the time . but ya , just found that out . I forgot about that photoshop quicky ...

"Wow! How'd you do that! That looks like somthing out of a movie!"
--some guy at work .

"Wow! How'd you do that! That looks like somthing out of a movie!"
--some guy at work .

[ycliao]

Thanks everyone for your help.
I found the way to do this.
I rendered out my animation in Targa sequence file and I brought them into Premiere. Then I exported as Filstrip format and I opened it in Photoshop.
Now I have alpha in my Filmstrip file.. I selected alpha and I applied Brightness/Contrast. Increasing Contrast & decreasing Brightness... I got my alpha with jaggy outside.
I brought it back to Premiere using that Alpha as my Alpha channel... I rendered them out as any sequence file.
Thanks everyone. I got this idea after reading all of your advice and suggestion.
Thanks.

[heydiddlediddle]

if i understand correctly, sounds like you want maya to render an unmultiplied alpha, I've only seen ElectricImage render out an image this way. But After Effects or any good compositing app should not get a halo around the edge, After Effects imports files with unmultiplied or premultiplied alphas, as does Wavefront Composer (if my memory isn't totally shot), as does the Quantel line (with some option which i forget what it's called). If you use your method you may end up losing some information from your rendered image, and i would suggest trying After Effects to do your "technique" since if you had say a 2000 frame sequence, doing anything to a filmstrip of it in photoshop could cause you to pull your hair out or bite your nails off while waiting. Premiere is no way to go if you need to do post on your 3d renders often, and if you have Photoshop 5 or higher, you could have just done a batch process on your images, Debabelizer would be another option to do such a batch process too.

[fredc]

Esn,
I still think everyone is going in circles on this (maybe just me). Is your goal to composite your objects rendered in Maya onto a different background without a halo around them, or trying to create some kind of an effect?

If you are only trying to composite "cleanly", then once you have targa sequence in Premier, just select Clip/Transparancy then use Alpha plane a method.

Your objects should now composite perfectly into your background or what ever is on the track behind it.

Hope this helps,
Urp

[ycliao]

Well, I'm trying to use that image in making a game.
Since we want to keep nice detail inside of our character, we gotta have antialiasing inside of our character and no antialiasing outside of our character to key off the background.
I hope everyone understands what I'm trying to do, and also talk about this further.
Thanks for your inputs.