RE: [Algorithms] VIPM With T&L - what about roam

[Martin F. <mf...@ac...>]

I assume you mean a single degenerate per coulumb per tile. (which was what
I was 
talking about)

Suppose you have a 4x4 heightfield section. If you draw 16 points on a piece
of
paper, start at the bottom left corner, connect to the point to the right of
this,
then the point immediatly above the start point, build a vertical strip and
you
will see at the top in order to get onto the next coulomb you only have to
use 
1 degenerate triangle.

Infact nDegeneratesTriangles = nCoulombs - 1.

While a 4x4 is impractically small on current hardware this gets the point
made.
The larger your tile the better the ratio of degenerates to normal triangles

becomes.


-----Original Message-----
From: Pai-Hung Chen [mailto:pa...@ac...]
Sent: 12 September 2000 02:24
To: gda...@li...
Subject: Re: [Algorithms] VIPM With T&L - what about roam


> Here's a question though. If I want to VIPM a heightfield is there anyway
to
>
> maintain a minimal indexed triangle strip. By minimal I mean as few strips
> and
> as few degenerate triangles as possible. A plain heightfield strips very
> well
> obviously with one strip per tile, (Assuming a quadtree split) with best
> case
> 1 degerenrate triangle per coulomb.
>
> It's all swings and roundabouts, there are cruder LOD techniques for
> heightfields ......

Could you elaborate a little bit on how to get "1 degenerated triangle per
tile"?

Thank you,

Paihung


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