Hello,

I have been playing around with povray and reading this newsgroup. I can 
understand that using SDL for creating scenes with simple objects or a 
combination thereof (cylinder, cone etc.) is quite handy (particularly 
for me since I have a programming background).

What I don't understand is how SDL can be used to create complex scenes 
with trees, people, faces etc. It would seem much more difficult to use 
SDL than a modelling program. Or does it require practice ? That is, 
once you start using SDL on a regular basis, you simply start imagining 
even complex scenes intuitively in math. Is that true ?

Regards,
Mahesh

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in news:3e9da0c8@news.povray.org Mahesh Padmanabhan wrote:

> What I don't understand is how SDL can be used to create complex scenes 
> with trees, people, faces etc.  [...]

The people that (want to) do everything in SDL have great Persistence. A 
feeling for spatial properties and math may help. Doing it all in SDL is 
often seen as a challenge by these people.
In general though, I think one can say that the majority of users uses a 
mixture of tools to get a result. Complex objects are made with a modeller 
or a very specific *.ini file. Then the compostion, texturing and lighting 
etc. is done in SDL.
My route in using POV-Ray was, first figure out how SDL works, then 
download every available (free) application that exports to POV-Ray. After 
a while I noticed that I only used a few of those. The rest is deleted. 
After toying around for a year or two, you'll see that you have collected 
a small but powerfull toolkit.
In the end, it's the image (result) that counts, not the tools you used.

Ingo

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ingo wrote:
> in news:3e9da0c8@news.povray.org Mahesh Padmanabhan wrote:
> 
> 
>>What I don't understand is how SDL can be used to create complex scenes 
>>with trees, people, faces etc.  [...]
> 
> 
> The people that (want to) do everything in SDL have great Persistence. A 
> feeling for spatial properties and math may help. Doing it all in SDL is 
> often seen as a challenge by these people.
> In general though, I think one can say that the majority of users uses a 
> mixture of tools to get a result. Complex objects are made with a modeller 
> or a very specific *.ini file. Then the compostion, texturing and lighting 
> etc. is done in SDL.
> My route in using POV-Ray was, first figure out how SDL works, then 
> download every available (free) application that exports to POV-Ray. After 
> a while I noticed that I only used a few of those. The rest is deleted. 
> After toying around for a year or two, you'll see that you have collected 
> a small but powerfull toolkit.
> In the end, it's the image (result) that counts, not the tools you used.
> 
> Ingo

Ahh, so your usage has been to use SDL for post-processing of complex 
scenes created with a modelling program. Yes, I can see the pragmatism 
behind that approach.

Thanks,
Mahesh

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in news:3e9db9ba$1@news.povray.org Mahesh Padmanabhan wrote:

> Ahh, so your usage has been to use SDL for post-processing of complex 
> scenes created with a modelling program.

I wouldn't call it postprocessing, it's more like photography. You don't 
expect the photographer to sculpture every piece that he uses in a 
still.

The works of Gilles Tran are a good example for this, in his early work 
he modelled a lot him self, in his late(est) work he even uses 
completely ready made objects (due to lack of time). Yet, still all his 
work has this "Tranesque" look and feel.

I compare the SDL to a very special kind of glue, with it you can use to 
stick together all kinds of objects from all kinds of sources, or, on 
the other side of the spectrum, you can do a complete scene with it as 
if it where a kind of clay.

In this regard, POV-Ray is a very versatile tool.

Have fun finding your way of using POV-Ray,

Ingo

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Mahesh Padmanabhan <new### [at] nospampranaemlcc> wrote:
> What I don't understand is how SDL can be used to create complex scenes 
> with trees, people, faces etc.

  Actually it's easier to make a tree with the SDL than with a modeller
(which does not support trees already). This is because a tree can be
created algorithmically.

  As for people, they aren't done with the SDL (alone) because that's simply
too difficult. Those are always made with modellers (and then imported to
POV-Ray).

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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Hi Mahesh,

very much can be done with pure, handwritten SDL. (That's what I do.) The
tools most important for me are the macros and while-loops of the SDL which
allow the automated calculation and construction of complicated shapes,
textures and scenes not easily achievable with modellers. The main exception
are meshes: they are usually created with modellers, sometimes by macros,
but never by handcoding.

Even if modellers are used, a good understanding of the SDL is neccessary
to get the best results.

I don't 'think in math', I see shapes, (textures, scenes,) try to find out
the POV-Ray-objets comprising them, decide what parameters to use to
describe them and their interconnections, write down the neccessary formulas
and algorithms and let POV-Ray do the rest. Then I play with these parameters
until I've got what I want.

Aside from reading the documentation and the newsgroups, asking questions,
performing many tests and trying to create some own work, a very effective
training method to get practice is: Try to help others! I've attempted this
very often (and with increasing success!), and although I rarely post my
answers because others are usually faster and have a better solution, this
was *very* helpful for me -- not only for learning SDL, but also for its
efficient and creative usage.

My advice is: read, read, read; then try, try, try yourself, don't be
satisfied if it's almost good, but try to make it as good as you can, and
even then try to make it better as soon as you have learnt more. Then post
your picture to povray.binaries.images and discuss the technical and the
artistic aspects of POVing: light, colors, textures, composition, and much
more. (Until now I haven't posted a picture [except bug demonstrations and
demonstrations for an include file of mine], but soon I will!)

Does practice make perfect? -- My answer is "no": raytracing is by far too
complex to let one be perfect in all technical and artistic aspects. But
without trying to be perfect, it's less fun, and practice helps a lot to
get this fun.


   Sputnik

--
-------------------------------------

e-mail: fr### [at] computermuseumfh-kielde
-------------------------------------

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In article <3e9da0c8@news.povray.org>,
 Mahesh Padmanabhan <new### [at] nospampranaemlcc> wrote:

> What I don't understand is how SDL can be used to create complex scenes 
> with trees, people, faces etc. It would seem much more difficult to use 
> SDL than a modelling program. Or does it require practice ? That is, 
> once you start using SDL on a regular basis, you simply start imagining 
> even complex scenes intuitively in math. Is that true ?

Part of it is simply practice and experience, part of it may just be a 
different way of thinking. I don't have much difficulty visualizing what 
the render will look like and writing code to generate it. Part of the 
trick is to split the job into smaller parts and go at them one by 
one...if you are trying to create an entire complex scene at once, you 
will get confused.

It is usually these specifics that are difficult...you mentioned people 
and faces, those are things that external modelling programs are 
typically used for. Trees, on the other hand, are just too complex to do 
by hand, a scripting language like POV uses makes it fairly easy.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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In article <3e9db9ba$1@news.povray.org>,
 Mahesh Padmanabhan <new### [at] nospampranaemlcc> wrote:

> Ahh, so your usage has been to use SDL for post-processing of complex 
> scenes created with a modelling program. Yes, I can see the pragmatism 
> behind that approach.

I think with most people it is more like using a modeller to create 
components of the scene, and the SDL to put everything together.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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