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John VanSickle schrieb:
> Yadgar wrote:
> >
> > Hi Tracers!
> >
> > Today, I fiddled around with exponential scaling of simple pigment
> > pattern, for example checker.
> > I made a checker pattern with rgb <1, 0, 0> and rgb <0, 0.5, 1> and made
> > an animation, during which it is scaled exponentially down to 1/10^11. I
> > hoped, that sooner or later, the two colors would blend into a
> > homogenous average color, such as rgb <0.5, 0.25, 0.5>. But instead, I
> > got strange interference patterns, sometimes single frames with
> > stretched patterns at much too large scale showed up.
> >
> > Then I tried AA, non-recursive, first at 0.3, than at 0 threshold - the
> > whole thing became fuzzier, but there are still those strange dropout
> > frames. Now I do it at threshold 0, still method 1, but with depth 9 -
> > calculation takes ages, and it's simply not proceeded far enough yet to
> > estimate the results. Is there any way to make any pigment pattern at
> > very small scales blend into one single color?
>
> You can build some anti-aliasing into the pigment. You have to know how
> much area is spanned by each pixel. Then you build several pigments,
> each one moved around slightly, and average them together. Apply this
> to your surface.
>
> I've done this in a couple of my IRTC entries. In "Robotany" the little
> placards in the background are pre-blurred for far-away shots. In
> "Revenge of the Greb" I blurred a brick pattern so that the rays would
> hit the mortar in a reliable way.
>
> Here is some sample code here:
>
> #local Brick=
> pigment {
> bozo color_map { [0 rgb .6] [1 rgb .5] }
> scale 30
> warp { repeat y*20 offset z*15 }
> }
>
> #local pigT111=pigment { brick
> pigment { rgb <.95,.85,.75> } , pigment { Brick }
> brick_size <30,20,15>
> mortar 1
> transform FlipXZ
> }
>
> #ifdef(BrickBlur)
> #local sD=vlength(BrickBlur-pCamL)/sCamZ/240;
> #local pigT111=pigment { average
> pigment_map {
> #local iI=-7; #while(iI<8)
> #local iJ=-7; #while(iJ<8)
> [1 pigT111 translate <0,iI,iJ>/16*sD ]
> #local iJ=iJ+2; #end
> #local iI=iI+2; #end
> }
> }
>
> #end
>
> In this code, BrickBlur is a spot on the wall that the camera is facing,
> sCamZ is the length of the direction vector in the camera, 240 happens
> to be the height of the image, and pCamL is the location of the camera.
>
> If you were to use this code, the camera would be specified this way:
>
> camera {
> direction z*sCamZ
> location pCamL
> look_at BrickBlur
> }
>
> Hope this helps.
>
> > Now playing: Don't Go (Yes)
>
> I've played that album continuously over the past three weeks! It's
> got some not-so-good tracks, but "Give Love Each Day" and "In the
> Presence Of" are great tracks.
>
> Regards,
> John
> --
> ICQ: 46085459
Hey, another Yes fan on this server! Really, this music is truly addictive...
can't count the hours I spent pixeling gigantic heightfields for my virtual
Afghanistan projects, with "The Ladder" or "Magnification" in the head-
phone...
But after getting to know the latest album by heart, I regret having bought
two titles you mentioned would have been an absolutely ecstatic experience to
me there, instead, they were just some new unknown pieces - and on stage, the
orchestra didn't come out as good as on CD.
And I remember that long ago, in early 2000, there was one guy here in the
newsgroup who rendered a stunning reproduction of Roger Dean's ABWH cover of
1989... I keep all pictures since 1999 on a CD (currently some 200 megs), but
I missed his name - and after a system crash, I only gradually recover my
original Netscape entry list of this group.
Your suggestions for anti-aliasing/blurring look intriguing... but up to
know, I hadn't found the time to try them, I hope I will do so in the coming
days! Do they also work with official PoV 3.1g or do have to tackle with
MegaPoV or 3.5?
See you in Khyberspace - http://www.geocities.com/electricafghan/index-e.html
Yadgar
Now playing: Pas de trois (Ashra - a German 70s electronic band which
influenced Ozric Tentacles very much)
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