Yes , I would concur that actual meshes would be the way to go ,
simply because displacement mapping ends up handcuffing you in so
many ways . Great for simple "nice rendering" scenario's however .
Yep, displacement can look great but has its drawbacks. Only suitable for
birds-eye views, you can't get too close. But I still love it!
I really have no idea how other landscape S/W's make it all
happen , but for RS , I would think a big mesh , and then have RS
take a look at it's resulting polygons , set up a database of how
you think an actual landscape might be broken up into catagories
(certainly more than lo/hi flat/sloped) and then have RS see which
polygons suit which catagory . Average out neighbouring polygons
and apply .
The polygons are still pretty big even in a quarter-million-points mesh,
you're asking for triangle artifacts this way... Example: a poly has a
single slope value because it's flat. This needs camouflaging. The
materials depending on slope should be 'smeared out' by adding some noise
or something, if not the polys stand out too much. I actually saw that
happen, it's not theory.
In phong shaded poly meshes, artifacts can occur occasionally where the
light angle is very small and perhaps a polygon casts a shadow onto itself
(???). In an attempt to reduce this, I tried to apply bumpy shadows: a kind
of shadow displacement (see manual materials/VSL/Bumpmapping at the end and
the example in tutorprojects), with interesting but inconclusive results.
However , as I said several mails ago , it would seem to be a big
effort and it would be great if a kind of 'group' was formed to attack
this project so as to eliminate all the duplicated wasted efforts on a
learning curve of this magnitude .
BFN
Garry Curtis
A few more tips:
- big meshes like 500x500 (250000 points) are NOT hard to render, 5 minutes
for a 800x600 picture is normal on a 1.5 GHz machine
- lots of memory is nice, 1 GB or more
- editing scenes with such big meshes can be very slow. Disabling Undo
helps a lot (set Undo depth to 0 in Prefs)
- don't convert triangular faces to quads.
Maybe a big tutorial when we figured it all out... or a book: "How to
attack a mesh with VSL" , that title will draw millions of readers ;)
I'll keep you posted,
Mark H
