[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Main character animations.

Steve Baker wrote:

> Gregor Mueckl wrote:
>>>You'll want to render at much higher resolution than you need so you can
>>>get them antialiased - also render against a 'blue screen' background so
>>>you can delete the background and have transparency in the right places.
>>Antialising and blue-screen backgrounds don't mix very good, mainly
>>because the pixel at the model's edges will be mixed with the
>>background. So if you enable antialiasing on such a scene you will have
>>a fixed-colored border around your model which is hard to get rid of.
> That's why you render at higher resolution - THEN extract the blue
> screen - so you now have an alpha (transparency) 'channel' in your
> image. THEN downsize the image to the scale you need to get the
> antialiasing effect.

I've thought about that one too at first, but that won't do the job 
unless you got a program that can downsize a selected area without 
bothering with the surrounding area in the picture. Otherwise you will 
create the same border as with antialiased rendering.

> Doing that will leave you with no fuzzy blue halo's whatsoever.
> Don't do it in the reverse order though (downsize and THEN extract
> the blue) or you will indeed get the effect you describe.
> Of course if your renderer can directly produce the alpha channel
> then by all means use that instead of a blue screen. (And of course
> when I talk about "Blue screen" you'll understand that it could
> be a green screen - or some yet less likely colour such as magenta).

As I described in my last posting, you can trick the renderer into doing that. It only needs support for ambient color on objects. Then you're even able to use antialiasing while rendering.


* Gregor Mueckl                 GregorMueckl@gmx.de *
*                                                   *
* The ChallengeOS project:                          *
* http://challengeos.sourceforge.net                *
* Math problems?                                    *
* Call 1-800-[(10x)(13i)^2]-[sin(xy)/2.362x].       *