Re: [Plib-devel] texture repeating

[Steve B. <sjb...@ai...>]

"Curtis L. Olson" wrote:

> Yes, setting the wrapu / wrapv to FALSE totally fixed this particular
> problem.

Good!

>  But it didn't help with the mipmap bluring when viewing my
> runways from edge on ... or the problem where different sections of
> the runway with different textures can't always have the same ft/pixel
> ratio so the mipmapping choices don't always blend nicely from one
> section to the next.
> 
> Runways are hard to get looking nice ... :-(

Yep.  The most critical object in the scene - drawn at the worst
possible angle at a place in the scene where the polygon count is
largest and where we can least tolerate poor frame rates. Then the
white lines on black tarmac are the highest contrast thing in the
scene and the thin side-stripes are most inclined to alias.

It would be hard to pick a nastier case.

At work, we don't use texture for runway markings - but in the absence
of antialiased polygon edges, you don't have a whole lot of choice...
although I've been playing with antialiasing on the GeForce cards - and
it looks pretty good...*almost* identical to SGI's ONYX in quality -
perhaps even slightly better at some angles.

> FYI, here's what I've got so far (as viewed from a mipmap friendly
> vantage point)
> 
>     http://www.menet.umn.edu/~curt/fgfs/Gallery/Link/kmsp-runway.html

I would add a tarmac-to-grass blend into the texture at the edges of the
runway to avoid the polygon aliasing along the outer edges of the white
stripes.

> > Joining two textures is a harder problem...for which I wrote a FAQ:
> >    http://web2.airmail.net/sjbaker1/tiling_textures.html
> 
> It's probably obvious to everyone (and now to myself as well) that you
> also need to have a consistant ft/pixel ratio along the edge you are
> matching... this could be something worth mentioning in the FAQ.

I guess - I kinda thought it was obvious - but it's hard to argue that
ANYTHING is obvious in a FAQ answer.

> > It's all rather disappointing for the purist though.
> 
> This whole mipmapping scheme sucks for edge on runways which is the
> view you see them at 95% of the time ... generating "squat" textures
> (more resolution cross-wise than length-wise) helps a lot but still
> leaves a *lot* to be desired. :-(

The answer is definitely 'RIPmapping' - but it's disappointingly
implemented only rarely on 'real' hardware.
 
-- 
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