POV-Ray : Newsgroups : povray.binaries.scene-files : how the **** do you make NICE grass ? Server Time: 18 Jun 2019 04:49:27 GMT
  how the **** do you make NICE grass ? (Message 1 to 7 of 7)  
From: Jonatan Hedborg
Subject: how the **** do you make NICE grass ?
Date: 21 Oct 1998 17:37:19
Message: <362E0E8D.5E59901A@tninet.se>
Hi!
How do i make nice grass?
in 3D, not colormap or whatever.
I want it realistic...
please help me!


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From: Ken
Subject: Re: how the **** do you make NICE grass ?
Date: 21 Oct 1998 19:03:20
Message: <362E21C9.696F3F92@pacbell.net>
Jonatan Hedborg wrote:

> Hi!
> How do i make nice grass?
> in 3D, not colormap or whatever.
> I want it realistic...
> please help me!

  That is one of the projects (pov related) that I am working on right now.
If I come up with something I'll let you know. My current strategy is tending
towards height fields but even that method lacks finesse in that you can't have
individual grasses overlapping each other on on a height field. Trying to do
blades of grass on an individual level is next to impossible on a pc unless you
nave 1000 megs of memory and a 1000 MHz processor. Well maybe I am
exaggerating a tad but it is difficult to distribute the quantities necessary to get
the right coverage and not end up with files producing  100k + or even
300 - 500k +  objects per scene.

Ken Tyler


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From: Peter Popov
Subject: Re: how the **** do you make NICE grass ?
Date: 22 Oct 1998 04:42:31
Message: <362ea9a7.0@news.povray.org>
See the FNORD animation and source in the respective newsgroups on this
server. This scene by Misha Moldavskuy aka Heretic features the best grass
I've seen in POV. Also, there was a post on using media to simulate fur,
check it out too (article "Fur" by Shinzano, posted in p-r.b.i. on Aug 6,
98)

Peter


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From: povray org admin team
Subject: Re: how the **** do you make NICE grass ?
Date: 22 Oct 1998 14:35:41
Message: <36303469.6971484@news.povray.org>
I'd be keen to see the results. I've got a model of my yet-to-be-built house
here that I'd like to add some better grass to ;).

Ken <tyl### [at] pacbellnet> wrote:

>Jonatan Hedborg wrote:
>
>> Hi!
>> How do i make nice grass?
>> in 3D, not colormap or whatever.
>> I want it realistic...
>> please help me!
>
>  That is one of the projects (pov related) that I am working on right now.
>If I come up with something I'll let you know. My current strategy is tending
>towards height fields but even that method lacks finesse in that you can't have
>individual grasses overlapping each other on on a height field. Trying to do
>blades of grass on an individual level is next to impossible on a pc unless you
>nave 1000 megs of memory and a 1000 MHz processor. Well maybe I am
>exaggerating a tad but it is difficult to distribute the quantities necessary to get
>the right coverage and not end up with files producing  100k + or even
>300 - 500k +  objects per scene.
>
>Ken Tyler


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From: Chris Cason
Subject: Re: how the **** do you make NICE grass ?
Date: 22 Oct 1998 15:13:13
Message: <362f3d79.0@news.povray.org>
>  That is one of the projects (pov related) that I am working on right now.
>If I come up with something I'll let you know. My current strategy is

I'd be keen to see any advances along this area. I have a POV model of my (as
yet unbuilt) house that I'd love to add some decent grass to.

-- Chris


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From: Lewis Sellers
Subject: Re: how the **** do you make NICE grass ?
Date: 15 Nov 1998 13:46:30
Message: <364ECCED.21D90E1D@usit.net>
Peter Popov wrote:
> 
> See the FNORD animation and source in the respective newsgroups on this
> server. This scene by Misha Moldavskuy aka Heretic features the best grass
> I've seen in POV. Also, there was a post on using media to simulate fur,
> check it out too (article "Fur" by Shinzano, posted in p-r.b.i. on Aug 6,
> 98)
> 
> Peter

You could of course always "cheat". Do some computations to figure out
the distance from the camera where grass should be, and if far enough
away just use texturing instead of objects. Not tried it. Might work.
get rid of a couple hundred thousand cones or so I'd guess.

Hmm. You could also try multiple height fields. Maybe three. slightly
pitched about with a rotate so that the grass can overlap.... hmm. If
you precompute a few cycles of grass into height fields you could even
do some "wind through grass" effects by sliding and tilting the hf's.
Tricky. but maybe.....

In the end, it doesn't matter if it structurely looks like a blade of
grass, only that it looks like a blade of grass enough that no one
notices otherwise. :)

--min


-- 
Lewis A. Sellers: writer and contract Multimedia Website Developer
mailto:lse### [at] usitnet (The Fourth Millennium Foundation)
http://www.public.usit.net/lsellers/ & http://www.intrafoundation.com
http://brain-of-pooh.tech-soft.com/users/critters/bios/sellers_lewis.html

You can bug the living bejesus out of me live on ICQ @ 491461
(If I don't get back to you within a month, I'm out of prozac in some
dark corner somewhere screaming things quite unintelligable but -- most
curiously -- thick with a sumerian accent.)

"The comedy is over" -i pagliacci


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From: Gordon
Subject: Re: how the **** do you make NICE grass ?
Date: 21 Dec 1998 04:54:53
Message: <367dd49d.0@news.povray.org>
There is a way!!!

Assume you want to cover a square 10x10 units.

First write a short routine to create a blade of grass as a mesh. Use say
4-8 triangles.
Place this inside a loop that creates, say, 1000x1000 blades of grass spread
over the 10x10 area.
This should end up as a single mesh{} object declared as, say, GrassPatch,
apply the texture to this object, not the individual blades.
Finally, use another set of loops to create, say 400 copies of the object
GrassPatch. Rotate these by random multiples of 90 degress around the
vertical axis, scale some of them by -1 to flip horizontally and translate
them by a random amount of +/- 1 units in the plane. This does put some
grass outside the fence, but makes the edges very realistic. You can always
clip the edges!

The net result is 400x1000x1000 blades of grass. A total of several BILLION
triangles. I have rendered these scenes with 64 Meg of memory with no
problems. They even render fast. The key is the fact that copies of mesh
objects are just pointers and you can have LOTS of them.

Using several different GrassPatch objects gives a very realistic patch of
grass/weeds/wheat/...

Hope that is useful.

Regards
Gordon
<gbe### [at] birdcameroncomau>

PS I didn't post the actual plug_in as its all at home and I'm at work. Mail
me if you want it.

Ken wrote in message <362E21C9.696F3F92@pacbell.net>...
>Jonatan Hedborg wrote:
>
>> Hi!
>> How do i make nice grass?
>> in 3D, not colormap or whatever.
>> I want it realistic...
>> please help me!
>
>  That is one of the projects (pov related) that I am working on right now.
>If I come up with something I'll let you know. My current strategy is
tending
>towards height fields but even that method lacks finesse in that you can't
have
>individual grasses overlapping each other on on a height field. Trying to
do
>blades of grass on an individual level is next to impossible on a pc unless
you
>nave 1000 megs of memory and a 1000 MHz processor. Well maybe I am
>exaggerating a tad but it is difficult to distribute the quantities
necessary to get
>the right coverage and not end up with files producing  100k + or even
>300 - 500k +  objects per scene.
>
>Ken Tyler
>


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