k1s3k1 nous apporta ses lumieres en ce 2007/08/16 20:53:
> thanks Marc  you helped me so much! i quite understand it now.. :)
> 
> By the way, is it possible to make the ground a big curvy, not flat? Because
> of rocks etc.. And how do i add shrubs ?
> 
> 
> 
You can use a very large, possibly flatened sphere. This will make it gently 
curve down from the center.
For example:
sphere{0, 10000 scale<5,0.01,5> translate -100*y}

It's possible to use an isosurface to do the same, with the benefit that you can 
alter the actual shape, but with a slower rendering speed.

-- 
Alain
-------------------------------------------------
You know you've been raytracing too long when you have ever brought your 
computer to its knees by mistakenly launching 64 simultaneous frames to be 
traced, while trying to maximizing the benefits of parallelizing them.
Carsten Whimster

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46c4f5c4$1@news.povray.org...
> You can use a very large, possibly flatened sphere. This will make it 
> gently curve down from the center.
> For example:
> sphere{0, 10000 scale<5,0.01,5> translate -100*y}
>
> It's possible to use an isosurface to do the same, with the benefit that 
> you can alter the actual shape, but with a slower rendering speed.
>
An other easy alternative, now that k1s3k1 has understood height_fields is 
to use a 2nd one made from a image created by POVRay.
It is sometimes easy to use the procedural textures to create images for 
height_fields.
I post 2 small example files in povray.binaries.scene-files (see topic 
"Rocky ground")

Marc

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can anyone teach me how to make plants/shrubs etc.. im having problem
finding it out :(

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web.46c9227d4683e647197c09550@news.povray.org...
> can anyone teach me how to make plants/shrubs etc.. im having problem
> finding it out :(
>
It's a 2 parts problem.
1st- you have to get shrubs.
You can make some with this kind of application
http://propro.ru/go/Wshop/povtree/povtree.html

2nd- you have to plant them.
There is a POVRay function called trace()
http://www.povray.org/documentation/view/3.6.1/229/  (item 2.2.1.4.5)

Some times ago, I put online a small tutorial for trace() (in French, sorry, 
but the code is the same for us all)
http://marc.jacquier.free.fr/tuts/trace_while/Trace_tut_page1.htm

Marc

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"M_a_r_c" <jac### [at] wanadoofr> wrote:

> web.46c9227d4683e647197c09550@news.povray.org...
> > can anyone teach me how to make plants/shrubs etc.. im having problem
> > finding it out :(
> >
> It's a 2 parts problem.
> 1st- you have to get shrubs.
> You can make some with this kind of application
> http://propro.ru/go/Wshop/povtree/povtree.html
>
> 2nd- you have to plant them.
> There is a POVRay function called trace()
> http://www.povray.org/documentation/view/3.6.1/229/  (item 2.2.1.4.5)
>
> Some times ago, I put online a small tutorial for trace() (in French, sorry,
> but the code is the same for us all)
> http://marc.jacquier.free.fr/tuts/trace_while/Trace_tut_page1.htm
>
> Marc

Thanks, but i dont understand at all -_-

I dont know how to start using trace.. is there a template of the code that
i can modify or something?

Because the french tutorial confuses me

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"k1s3k1" <k1s### [at] gmailcom> wrote:
> "M_a_r_c" <jac### [at] wanadoofr> wrote:

> > web.46c9227d4683e647197c09550@news.povray.org...
> > > can anyone teach me how to make plants/shrubs etc.. im having problem
> > > finding it out :(
> > >
> > It's a 2 parts problem.
> > 1st- you have to get shrubs.
> > You can make some with this kind of application
> > http://propro.ru/go/Wshop/povtree/povtree.html
> >
> > 2nd- you have to plant them.
> > There is a POVRay function called trace()
> > http://www.povray.org/documentation/view/3.6.1/229/  (item 2.2.1.4.5)
> >
> > Some times ago, I put online a small tutorial for trace() (in French, sorry,
> > but the code is the same for us all)
> > http://marc.jacquier.free.fr/tuts/trace_while/Trace_tut_page1.htm
> >
> > Marc
>
> Thanks, but i dont understand at all -_-
>
> I dont know how to start using trace.. is there a template of the code that
> i can modify or something?
>
> Because the french tutorial confuses me

Hi k1s3k1,
 Trace is the way to go for accuracy but it might not be a good idea if you
have a deadline. You could try placing your shrubs manually and adjust

can move your camera away from its final position so that you can see where
you have placed the objects.
IMO if this project is an assignment make sure that you have something you
can hand in first then tidy it up and make it look good. You seldom get
marks for spending all of your time experimenting with no results.



Stephen

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k1s3k1 nous apporta ses lumieres en ce 2007/08/22 09:21:
> "M_a_r_c" <jac### [at] wanadoofr> wrote:
>> "k1s3k1" <k1s### [at] gmailcom> a écrit dans le message de news:
>> web.46c9227d4683e647197c09550@news.povray.org...
>>> can anyone teach me how to make plants/shrubs etc.. im having problem
>>> finding it out :(
>>>
>> It's a 2 parts problem.
>> 1st- you have to get shrubs.
>> You can make some with this kind of application
>> http://propro.ru/go/Wshop/povtree/povtree.html
>>
>> 2nd- you have to plant them.
>> There is a POVRay function called trace()
>> http://www.povray.org/documentation/view/3.6.1/229/  (item 2.2.1.4.5)
>>
>> Some times ago, I put online a small tutorial for trace() (in French, sorry,
>> but the code is the same for us all)
>> http://marc.jacquier.free.fr/tuts/trace_while/Trace_tut_page1.htm
>>
>> Marc
> 
> Thanks, but i dont understand at all -_-
> 
> I dont know how to start using trace.. is there a template of the code that
> i can modify or something?
> 
> Because the french tutorial confuses me
> 
> 
> 
Trace:
You need to pick a starting point somewhere above the surface you want to test.
Then, you need a trace direction. In your case, it's -y or traight down.
It gives you this:
#declare Normal = <0,0,0>;
#declare Point = trace(My_Position, -y, Normal);

Where Normal return the prependicular to the traced point, if = 0 it means that 
you missed your terrain.
Point is the coordinates of the point of your terrain directly under My_position.

The next step is to place your tree, or anything you want, on the terrain:
object(Tree translate Point)

-- 
Alain
-------------------------------------------------
The tree of liberty must be refreshed from time to time with the blood of
patriots and tyrants.
Thomas Jefferson

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k1s3k1 wrote:
>...
> I dont know how to start using trace.. is there a template of the code that
> i can modify or something?
> 
You might take a look at trace.pov and trace2.pov in the POV examples. 
They're in scenes/language.

      -=- Larry -=-

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"k1s3k1" <k1s### [at] gmailcom> wrote:


>
> Thanks, but i dont understand at all -_-
>
> I dont know how to start using trace.. is there a template of the code that
> i can modify or something?

TRACE *can* be a bit mysterious for a new user.  (And we were ALL new users
at one time, so don't worry!) Once you understand it, it will seem simple.
Really!

In its simplest form, the trace function *gives* you a value, just a single
value, a *point* that it finds for you on a surface (your mountains, in
this case.) You need to plug three "things" into the trace function for it
to work:
1) Your object-to-trace.
2) a point in space that the single imaginary trace "ray" comes from--a
vector. For example, <.5,100,.5>. That would put it above and centered over
a 1X1 heightfield. A good place to start!
3) the direction of that trace ray--toward your object, of course--which is
another "vector," but it's really a DIRECTION--like <0,-1,0>, which means
"pointing in -y", or straight down. That's the easiest direction to
understand, until you get a feel for how trace works. But make sure that #2
and #3 together WILL point the trace ray somewhere at your mountains!!

To use trace at all, you need to #declare it with a name:

#declare my_point  = trace(mountain_object, <.5,100,.5>, <0,1,0>);  Don't
forget the semi-colon!

That actually starts the tracing operation!  Very simple. And my_point now
contains the value--a vector--that is the point on your mountains that the
trace "ray" hit. You use that vector to place another object there.  For
example,
object{bush_object translate my_point}

But to really use trace to its fullest, you'll need to learn about #while
loops and random numbers  (seed and rand), so that you can trace your
mountains hundreds of times, to put LOTS of bushes on it.

Have fun!

Ken W.

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"Kenneth" <kdw### [at] earthlinknet> wrote:

> To use trace at all, you need to #declare it with a name:
>
> #declare my_point  = trace(mountain_object, <.5,100,.5>, <0,1,0>);  Don't
> forget the semi-colon!

OOPS!  I made a slight error; it should be
#declare my_point  = trace(mountain_object, <.5,100,.5>, <0,-1,0>);

I hope that didn't confuse you.  Sorry!

Ken W.

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