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

[Brian M. <bma...@ra...>]

	I've been thinking about this more. The requirements for the hardware I'm
working with are somewhat different - I get maximum benefit from very long
strips, since the hardware has a very different caching scheme to G-Force
etc.

	I'm currently edging towards trying a combination of skip strips and your
suggestion Tom, of precomputed strips for various levels. The idea would be
to precompute good sets of strips at reasonable values, and use skip strips
to maintain the strips during edge collapses.
	During PM computation you start with doing a full stripification of the
model. Then as you do each collapse you rate the current set of strips - how
many degeneracies, how long etc. So when the strip quality reaches a user
set threshold you regenerate the strips. That way the user can set the
trade-off between memory usage (for extra sets of strips.) and rendering
efficiency. For an ultimate version you could recompute a new set of strips
for each edge collapse to compare the efficiency of the current skip-strips
against. Then you can decide exactly when to issue new strips. Not something
to do when the art team are working on the model, but should work great
overnight.

	There are a couple of problems I can see:
1. The edge collapse records get more complex - you need to issue sets of
strips as well.
2. The runtime memory state required is somewhat larger - you may need 2
sets of strips (the second having excess degenerate tri's removed for
efficiency), as well as more complex collapse records and extra data for the
sets of strips to restart things.

-Brian.

> Cool. I'll have a look at the second one of those. The first one
> (skipstrips) was discussed here a while back, and led to me burbling this,
> which bears repeating for those who recently joined us (especially as
> someone asked for it):