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From: Tim
Subject: Grass 'n' Glass
Date: 5 Apr 2006 17:35:00
Message: <web.44343684146b5f1439c1f1d20@news.povray.org>
To be honest I'm very nervous about posting an image here as I only
discovered POVRay since the 26th.  Thoroughly enjoying it though as I've
been ill for over a year now so no longer have a job in software
development and I can't get out anymore to do my photography.  Ah well, I
think this could be a lifelong passion!

On to the image.  The reason I'm posting it is because I wrote a macro (over
the past three or four days) to create Meadow Foxtail, each one having
random differences from the others.  I completed it tonight and thought I
would post it here as others have done with their macros in the past.
Before I got round to it though I thought it was about time I actually
created a full scene, and I don't think it's too bad for an extra half hour
work (although perhaps a little tacky).  So primarily I hoped someone would
comment on the Meadow Foxgrass itself, but secondly if anyone has any
comments on the scene I would love to hear them too.

And one last thing, kindly please!  I'm only a baby pover!  :D


Tim


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From: Zeger Knaepen
Subject: Re: Grass 'n' Glass
Date: 5 Apr 2006 19:10:57
Message: <44344e81$1@news.povray.org>
Reminds me of a Blake's 7 episode, Shadow.

To comment on the image: it's strange seeing grass grow from a 
reflective plane, but I like the effect :p

cu!
-- 
#macro G(b,e)b+(e-b)*C/50#end#macro _(b,e,k,l)#local C=0;#while(C<50)
sphere{G(b,e)+3*z.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1;
#end#end _(y-x,y,x,x+y)_(y,-x-y,x+y,y)_(-x-y,-y,y,y+z)_(-y,y,y+z,x+y)
_(0x+y.5+y/2x)_(0x-y.5+y/2x)            // ZK http://www.povplace.com


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From: Bob H
Subject: Re: Grass 'n' Glass
Date: 5 Apr 2006 19:13:45
Message: <44344f29$1@news.povray.org>
A great start going with a macro already. I guess some people like me still 
don't take advantage of that in POV as much as should be, since it's 
something fairly new that came along after so many version changes.

I wasn't sure what this plant is (nor what most anything is) so I did a 
google image search for it. Pictures almost always show longer "foxtails" 
than yours here. Maybe they're different in different places or times of 
year?

Only thing I was going to suggest is maybe using a green to yellow variation 
for the stalks, and the pictures I saw show that's possible in the actual 
plants. Probably something again that varies with particular varieties and 
times of year, just that plain green doesn't seem as true to life when 
rendering a plant.

Looks like you used a light directly above the plant that makes most of the 
tops dark. Not sure if that was your intention but guessing you tried to 
show both lit and unlit sides. The lack of shadows on the ground (or water) 
is interesting.

Oh, and welcome to the newsgroups and your new hobby! You're off to a 
fantastic start-- even if you didn't post a reflective sphere over checkered 
plane per tradition (I didn't either).
-- 
Bob H  www.3digitaleyes.com
http://3digitaleyes.com/imagery/


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From: Tim
Subject: Re: Grass 'n' Glass
Date: 5 Apr 2006 20:40:00
Message: <web.443462002c9ee25b39c1f1d20@news.povray.org>
"Zeger Knaepen" <zeg### [at] povplacecom> wrote:
> Reminds me of a Blake's 7 episode, Shadow.
>
> To comment on the image: it's strange seeing grass grow from a
> reflective plane, but I like the effect :p

I tried to find whatever Blake 7 thing it is the picture reminds you of but
had no luck.  I like graphics where there is something subtle but obviously
(if that makes sense) "wrong" or "strange", and I'm dead chuffed you like
the effect I've used here.  Thanks for the comment.  :D



"Bob H" <omniverse@charter%net> wrote:
> A great start going with a macro already. I guess some people like me still
> don't take advantage of that in POV as much as should be, since it's
> something fairly new that came along after so many version changes.

I didn't realise this was a fairly new feature.  I thought constructing
macros was a good place to start learning to pov given that I used to be a
developer, and whatever I write can be used in future pictures if they're
reusable enough.


> I wasn't sure what this plant is (nor what most anything is) so I did a
> google image search for it. Pictures almost always show longer "foxtails"
> than yours here. Maybe they're different in different places or times of
> year?

I grew up in the Scottish countryside and this grass grows everywhere there.
 It's THE plant which makes me think of summer which is why I wanted to
model it.  I sent a copy of the picture to my father as he's clued up on
botany and nature in general and he said the same thing about the foxtails.
 I thought the same thing too, but what bothers me is that the botany site I
used as reference says they are between 5-8cm long which is exactly the
range I've used.  Last night I spent a few hours reconstructing the foxtail
to make it *appear* longer but can do no more.  So when the Meadow Foxtail
grows again I intend to check the length myself, and change it if
necessary.  My other option is to reduce the range to something line 7-8cm.
 If that doesn't help though I'm going to be at a loss whether to
inaccurately lengthen them for appearence or not.  :-/


> Only thing I was going to suggest is maybe using a green to yellow variation
> for the stalks, and the pictures I saw show that's possible in the actual
> plants. Probably something again that varies with particular varieties and
> times of year, just that plain green doesn't seem as true to life when
> rendering a plant.

Again I agree with you, but again I'm going to wait until it grows so I can
check the colour variations in detail!


> Looks like you used a light directly above the plant that makes most of the
> tops dark. Not sure if that was your intention but guessing you tried to
> show both lit and unlit sides. The lack of shadows on the ground (or water)
> is interesting.

Not being used to 3d rendering I used a typical (and very basic) lighting
setup in my closeup natural photography.  The main light is coming from the
left-rear, while a weaker light from the right-rear fills in the shadows
while retaining the texture.  At least that's the plan!  The difference in
lighting with the tops is because each foxtail is covered in about 100
(give or take) tiny cylinders at an angle (with a slight randomness).  I'm
not convinced its 100% accurate but I thought it gave a good idea to the
feel of the real plant.


> Oh, and welcome to the newsgroups and your new hobby! You're off to a
> fantastic start-- even if you didn't post a reflective sphere over checkered
> plane per tradition (I didn't either).

Thank you loads for the comments, and I do appreciate that you've taken the
trouble to look for pictures of the real plant.  I'm off to have a go at
that great idea of an image you've suggested!  ;-)


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From: Bob H
Subject: Re: Grass 'n' Glass
Date: 6 Apr 2006 00:48:26
Message: <44349d9a$1@news.povray.org>
"fairly new" was a slip of the tongue. I should have worded that another 
way. I've used POV-Ray for about 12 years now and the macro feature was 
added to version 3.1. Sure, maybe it's been a half-dozen years since then 
but I can be slow to adapt.  ;)

Back to your rendering...
Thanks for explaining the lighting used. Looking at it with higher 
brightness here now, I can see them better than before. I was going to 
mention potential for the well-known coincident surfaces problem, but I'm 
not really able to see anything wrong concerning that so I suppose the 
randomness is preventing that. The small size of those things makes it 
impossible to be sure anyway, but it would show up as either blank or 
speckled parts if the cylinder ends matched. It's the extreme darkness of 
them that just looks wrong to me with that whiteness all around, something 
'radiosity' might help with to illuminate them more.

I've tried to find out what kind of plant this reminds me of. Something I 
was always plucking from the ground and tearing apart when I was a kid in 
Washington (northwest US). Apparently called buckthorn but this is the only 
relevant photo I could locate and it isn't a very good one. They didn't have 
thorns so I don't know why the name.

http://www.plantsgalore.com/articles/weeds/images/Weed_Buckthorn.jpg

The flowering top parts can look much like the middle two in your plant 
before they turn into tiny flowers. That plant just seemed to attract me to 
ripping it apart, kind of like blowing on dandelion fluff did.


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From: Tim
Subject: Re: Grass 'n' Glass
Date: 6 Apr 2006 06:40:00
Message: <web.4434efd32c9ee25b39c1f1d20@news.povray.org>
Hehe, looking at the picture you linked to it looks very much like a common
weed I used to rip apart as a kid!  It was as if it had a label on it
saying "Destroy Me."  Coincidentally though, halfway through writing the
macro I realised it wouldn't take much to create another macro to create
that plant.

I'm sure there's no problem with coincidence surface problems as I chose the
angles and vertical gaps to avoid that.  I think if thhat problem existed
the heads would appear as black splodges as there are just so many
cylinders.  I double checked the darkness issue and verified it is simply
because of the angles of the cylinders when the plant is turned around.  I
tried altering the radiosity but I didn't like the results.  Instead I've
ensured that none of the stems are placed at such an angle to cause the
problem.  I'm thinking (hoping) that the contrast between the stems is
going to add some depth and interest to any future landscape images I use
this macro in.

I noticed a fault with the generation of the leaf blade meshes, so rewrote
that part to provide a better and more varied curve and to stop them looing
like thin wire clones of eachother.

Finally I found a website which specifies the heads to be 9cm long so my
random value is now from 7-9cm.  That and a little jiggery pokery I did
with the seeds/cylinders and I reckon they look good now.  The picture has
grown on me now so although I know it's not up to the standard of most of
the pictures here, I'll probably post and hope for more feedback!

Tim


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From: Tim
Subject: Re: Grass 'n' Glass
Date: 6 Apr 2006 11:40:00
Message: <web.443535492c9ee25b39c1f1d20@news.povray.org>
I received an email asking if I could send the macro for this, so I'm gladly
posting it into the binary utilities newsgroup.  Below is an updated image
which shows the improvements I've made.

Tim


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From: Ross
Subject: Re: Grass 'n' Glass
Date: 6 Apr 2006 11:48:54
Message: <44353866$1@news.povray.org>
"Tim" <tim### [at] gmailcom> wrote in message
news:web.44343684146b5f1439c1f1d20@news.povray.org...
> To be honest I'm very nervous about posting an image here as I only
> discovered POVRay since the 26th.  Thoroughly enjoying it though as I've
> been ill for over a year now so no longer have a job in software
> development and I can't get out anymore to do my photography.  Ah well, I
> think this could be a lifelong passion!

it does quickly become an obsession :)


>
> On to the image.  The reason I'm posting it is because I wrote a macro
(over
> the past three or four days) to create Meadow Foxtail, each one having
> random differences from the others.  I completed it tonight and thought I
> would post it here as others have done with their macros in the past.
> Before I got round to it though I thought it was about time I actually
> created a full scene, and I don't think it's too bad for an extra half
hour
> work (although perhaps a little tacky).  So primarily I hoped someone
would
> comment on the Meadow Foxgrass itself, but secondly if anyone has any
> comments on the scene I would love to hear them too.
>
> And one last thing, kindly please!  I'm only a baby pover!  :D

Nice work. For the stems, the ones that go crooked look a little too sharply
crooked. For the scene, i'd change the lighting somewhat. Maybe add a dim
fill light directly behind the camera (so as to not cast unwanted shadows),
or use some radiosity. Otherwise, it's a perfectly fine first posting to the
group.

-r


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From: Tim
Subject: Re: Grass 'n' Glass
Date: 6 Apr 2006 12:35:00
Message: <web.443541ee2c9ee25b39c1f1d20@news.povray.org>
Hi Ross,

> Nice work. For the stems, the ones that go crooked look a little too sharply
> crooked.

Hmmm, I think that must be the lighting.  For the stems I simply took a
random length within a given range, multiplied it by 16 and created a torus
with that circumference, then took 1/16th out which gave the final bend to
the stem.  This way I could use polar coordinates to find any point I
needed to.  On the other hand... :)  if you mean the angle they're leaning
to you may be right!  My intentions are to examine the meadow foxtail
directly when the time of year comes around.  And if I get the chance I'll
study it's movement in various wind conditions and add an interface to use
that information.

> For the scene, i'd change the lighting somewhat. Maybe add a dim
> fill light directly behind the camera (so as to not cast unwanted shadows),
> or use some radiosity. Otherwise, it's a perfectly fine first posting to the
> group.
>
> -r

Your right about the lighting, there's no other word for it!  I only quickly
rendered a half hour scene last night to show the plant really.  I tried
playing with the light settings this afternoon after chatting with Bob H
but could only make it worse!  To tell the truth I gave up, deciding that
with so much light bouncing about it wasn't the best scene to learn on.
There's no denying it, I chickened.  :-/  Thanks for your comments though.
I was expecting to be cut down today as I know it can be so easy to like
anything you put alot of effort into regardless of what it looks like, and
it's nothing compared to the other images on this site, but the comments
I've received so far have been a big confidence booster.

Tim

Btw the macro is posted to the binary utilities now so I hope people can
make some use of it.


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From: St 
Subject: Re: Grass 'n' Glass
Date: 7 Apr 2006 15:53:42
Message: <4436c346@news.povray.org>
"Tim" <tim### [at] gmailcom> wrote in message 
news:web.44343684146b5f1439c1f1d20@news.povray.org...



> To be honest I'm very nervous about posting an image here as I only
> discovered POVRay since the 26th.

 Hiya Tim, welcome to the world of PovRay. Don't be nervous though, there 
are a whole bunch of people around here with varying expertise in many 
aspects of... erm, life, and CG art! If they can help in any way, they will, 
so just ask away in any of the groups for your subject.



>Thoroughly enjoying it though as I've
> been ill for over a year now so no longer have a job in software
> development and I can't get out anymore to do my photography.  Ah well, I
> think this could be a lifelong passion!


    And a passion it is. A wholehearted one for me and many, many others. I 
hope you enjoy it as much as I've seen many people here enjoy it.


>
> On to the image.  The reason I'm posting it is because I wrote a macro 
> (over
> the past three or four days) to create Meadow Foxtail, each one having
> random differences from the others.

  I like it, and I see where you're getting that angle on the leaves from. 
It's a very similar grass to the Timothy Grass we have here in the UK: 
http://strubi.uni-graz.at/projects/allerg_03.jpg


 I completed it tonight and thought I
> would post it here as others have done with their macros in the past.
> Before I got round to it though I thought it was about time I actually
> created a full scene, and I don't think it's too bad for an extra half 
> hour
> work (although perhaps a little tacky).  So primarily I hoped someone 
> would
> comment on the Meadow Foxgrass itself, but secondly if anyone has any
> comments on the scene I would love to hear them too.

   Well, Googling images of the Meadow Foxtail, I notice that the actual 
shape of the flower-head(?) is more of a torpedo shape, maybe you could try 
that out? Generally though, your image is a nice, relaxing, mellow scene. A 
good start.

  (Sheesh! Listen to me. I sound like a teacher writing a school report! 
Anyway, you're A+ at the moment...)     ;)


>
> And one last thing, kindly please!  I'm only a baby pover!  :D

    Ok, we'll let you off just this once...

    Oh, and don't forget the 'Reflective Sphere Over Chequered Plane' thing 
that goes on around here. See if you can come up with something different.

   Liked the later image too.   :o)

       ~Steve~


>
>
> Tim


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