Darn, my news reader just crashed as I was writing a reply to this! I'll try and
remember what I said...

Basically it's just a mesh. Each blade is triangular, and is divided in two
along it's length so I can texture it. The texture is uv mapped so that the
blade is opaque at the center of it's base, and fades to transparent at the
edges. This gives a nice soft appearance without the need for hundreds of focal
blur samples :) The blades also vary slightly in colour.

Each blade is placed using the trace() function, by firing a ray vertically down
onto the object. The blade is oriented to point in the direction of the surface
normal, and then the top point is displaced by a vturbulence() function and a
small random displacement.

Here's a couple of bits of source code to help explain that:

//trace a position onto the object
#macro m_Place(vP)
 (trace( oHill, vP+y*5, -y + .3*(<rand(rs),rand(rs),rand(rs)>-.5), vPlaceNorm )
+ vP.y*y)
#end

#declare vPos = 1.3*<rand(rs)*2-1,0,rand(rs)*2-1>;
#declare vPos = m_Place(vPos);

#declare vTop = vPos + vPlaceNorm*.0025;
#declare vTop = vTop + (vturbulence(2, .5, 6, vPos*20)*.0004 +
(<rand(rs),rand(rs),rand(rs)>-.5)*.0004)*<1,.3,1>;

I can post the full source if you like, but I'll probably carry on working on
this image so I'd rather wait until it's "finished".

--
Tek
http://www.evilsuperbrain.com


"Tim Nikias v2.0" <tim### [at] gmxde> wrote in message
news:3eebbd41$1@news.povray.org...
> Would you care to explain a little more in detail how you've
> gone about creating the grass? Placing, object's orientation,
> how many are there, texturing? It looks really great.
>
>
> --
> Tim Nikias v2.0
> Homepage: http://www.digitaltwilight.de/no_lights
> Email: Tim### [at] gmxde
>
> > > Fantastic! Add some flowers, bees or butterflys,
> > > position the camera a little different to make
> > > the fractal more visible, and you've made yourself
> > > a picture worthy of Zazzle!
> >
> > Good ideas, that's the kind of thing this scene needs. Though at the
> moment I'm
> > playing with the lighting instead...
> >
> > I have to admit I didn't think it was that good, but people really seem to
> have
> > picked up on the atmosphere of it so I think I'll develop it further :)
> >
> > --
> > Tek
> > http://www.evilsuperbrain.com
> >
> >
>
>

Post a reply to this message