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From: rebeltaz
Subject: how to visualize what you want?
Date: 17 Jul 2010 03:50:00
Message: <web.4c415fa19a99249a516ec1d10@news.povray.org>
I used POV ten or fifteen years ago and it was a Windows-based GUI system. I
have long since forgotten everything that I knew, and I have moved on to Linux.
Since there aren't many, if any, GUI modeling programs for Linux, I was looking
at the tutorials on writing the code in a text editor. While I am perfectly
capable of writing code using a text editor in numerous BASIC, C++, PHP and HTML
languages, that's more of an abstract process.

What I am curious about is hard to explain. I guess... how do you 'see' what you
are designing when you are only working with code. How do you know that the
camera goes here. How do you that this shape is at these coordinates. I guess I
am having a hard time understanding how you plot an image that you can't see.

I hope what I am asking makes sense. I'm not asking for a tutorial on how to
write the code. More of the mentality behind writing the code. Or maybe I am
missing something?

Thanks for your patience in reading this (since you got this far :)


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From: Warp
Subject: Re: how to visualize what you want?
Date: 17 Jul 2010 04:10:32
Message: <4c416577@news.povray.org>
rebeltaz <mrm### [at] bellsouthnet> wrote:
> What I am curious about is hard to explain. I guess... how do you 'see' what you
> are designing when you are only working with code. How do you know that the
> camera goes here. How do you that this shape is at these coordinates. I guess I
> am having a hard time understanding how you plot an image that you can't see.

  You visualize the space in your head, and you make lots of test renders.
Perhaps not the most efficient process in existence, but it's workable.
(Besides, it trains your spatial recognition skills, which is always a plus.)

-- 
                                                          - Warp


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From: Jim Holsenback
Subject: Re: how to visualize what you want?
Date: 17 Jul 2010 05:44:18
Message: <4c417b72$1@news.povray.org>
On 07/17/2010 04:45 AM, rebeltaz wrote:
> What I am curious about is hard to explain. I guess... how do you 'see' what you
> are designing when you are only working with code. How do you know that the
> camera goes here. How do you that this shape is at these coordinates. I guess I
> am having a hard time understanding how you plot an image that you can't see.

You might find it useful (I do) to create a crude grid out of cylinders
... something that marks <0,0,0> and each of the directions x,y,z
positive and negative (color coded) with some sort of tic mark(s), say
every 5 units ... save it as an include file then conditionally include
when you need it :-)

Jim


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From: Bill Pragnell
Subject: Re: how to visualize what you want?
Date: 17 Jul 2010 07:00:00
Message: <web.4c418c41f4e69ab44f28787e0@news.povray.org>
What Warp said.

It basically boils down to experience I think - you run test renders, and
eventually you just end up needing fewer test renders. I think many of the
posters here have used POV (as you did) long before gui-based modellers became
common (and/or free), and it's just practice. Of course there are things you can
do to aid the process, as Jim suggested. You might find some old ways of
thinking come back to you quicker than you expect!


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From: Thomas de Groot
Subject: Re: how to visualize what you want?
Date: 17 Jul 2010 11:23:02
Message: <4c41cad6$1@news.povray.org>
"Bill Pragnell" <bil### [at] hotmailcom> schreef in bericht 
news:web.4c418c41f4e69ab44f28787e0@news.povray.org...
> What Warp said.
>
> It basically boils down to experience I think - you run test renders, and
> eventually you just end up needing fewer test renders. I think many of the
> posters here have used POV (as you did) long before gui-based modellers 
> became
> common (and/or free), and it's just practice. Of course there are things 
> you can
> do to aid the process, as Jim suggested. You might find some old ways of
> thinking come back to you quicker than you expect!
>

And in addition, just the old pencil and paper. I use a lot of that too, 
from arithmetics to sketches.

Thomas


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From: Jim Henderson
Subject: Re: how to visualize what you want?
Date: 17 Jul 2010 12:57:08
Message: <4c41e0e4$1@news.povray.org>
On Sat, 17 Jul 2010 03:45:37 -0400, rebeltaz wrote:

> Since there aren't many, if any, GUI modeling programs for Linux

Blender and wings3d are two that come immediately to mind.

Jim


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From: J R Houck
Subject: Re: how to visualize what you want?
Date: 17 Jul 2010 17:30:42
Message: <4c422102$1@news.povray.org>
On 7/17/2010 10:57 AM, Jim Henderson wrote:
> On Sat, 17 Jul 2010 03:45:37 -0400, rebeltaz wrote:
>
>> Since there aren't many, if any, GUI modeling programs for Linux
>
> Blender and wings3d are two that come immediately to mind.
>
> Jim

I use Wings3d quite a bit to set primitives around the scene and give 
them descriptive names. After the .pov and .inc files are exported, I 
can go back and hand edit the files and insert or modify the objects I 
want. Wings will handle a lot of primitives as well as more complex 
objects by default, converting them to mesh2 objects in an .inc file. 
However, Wings3D won't to CSG operations or more complex objects like 
quartics.

So, since Wings3d won't do a quartic object, I'll place a cylinder 
somewhere in the scene and name it "quartic_1" or similar. Then I can 
edit the exported files, find "quartic_1" and work in the code I wish to 
have there.

It sounds a bit complicated, but actually, once you get your scene set 
up, it goes fairly quickly. YMMV.

Cheers.


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From: rebeltaz
Subject: Re: how to visualize what you want?
Date: 18 Jul 2010 00:40:00
Message: <web.4c4284b1f4e69ab4516ec1d10@news.povray.org>
I was thinking maybe pencil and graph paper like Thomas suggested.

jim mentioned Blender for Linux. I tried Blender a couple of months ago when I
needed a CAD program for the new CNC machine I built and I could not make heads
or tails out of it. I do like Sketchup and I saw a post here about a SU2POV
plugin. I think I may give that a try and see how it works.

I really appreciate all of the advice and comments...


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From: Thomas de Groot
Subject: Re: how to visualize what you want?
Date: 18 Jul 2010 04:42:14
Message: <4c42be66$1@news.povray.org>
"rebeltaz" <mrm### [at] bellsouthnet> schreef in bericht 
news:web.4c4284b1f4e69ab4516ec1d10@news.povray.org...
>I was thinking maybe pencil and graph paper like Thomas suggested.
>

And don't forget Warp's suggestion. Mental visualization, even the most 
complex ones, comes first, often even before paper and pencil.

Thomas


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From: Jim Charter
Subject: Re: how to visualize what you want?
Date: 31 Jul 2010 11:07:45
Message: <4c543c41@news.povray.org>
rebeltaz wrote:
> I used POV ten or fifteen years ago and it was a Windows-based GUI system. I
> have long since forgotten everything that I knew, and I have moved on to Linux.
> Since there aren't many, if any, GUI modeling programs for Linux, I was looking
> at the tutorials on writing the code in a text editor. While I am perfectly
> capable of writing code using a text editor in numerous BASIC, C++, PHP and HTML
> languages, that's more of an abstract process.
> 
> What I am curious about is hard to explain. I guess... how do you 'see' what you
> are designing when you are only working with code. How do you know that the
> camera goes here. How do you that this shape is at these coordinates. I guess I
> am having a hard time understanding how you plot an image that you can't see.
> 
> I hope what I am asking makes sense. I'm not asking for a tutorial on how to
> write the code. More of the mentality behind writing the code. Or maybe I am
> missing something?
> 
> Thanks for your patience in reading this (since you got this far :)
> 
> 

A small idiosyncratic note related to positioning the camera.  I try to 
leave the main focus of my scene at the origin or maybe directly above 
the origin. So I point the camera there.  I then position the camera, 
and sometimes the lights too, utilizing the vrotate command.  Personally 
I have found this a more intuitive way to control the distance and angle 
of the camera to a subject.

e. g.
camera {
   location  vrotate ( <0,0,-10>, <20,30,0> )
   look_at   <0.0, 0.0, 0.0>
}	
This would place the camera at 10 units distance along the -z axis then 
rotate it around the subject, upward 20 degrees, then to the left 30 
degrees.


It is not for every situation, of course. Sometimes you know you want to 
locate the camera 'over behind the couch' or 'at the eye height of a 
figure in the doorway' and have it look at 'the center of the table', 
and so you do that with simple vectors like all the other objects.


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