POV-Ray : Newsgroups : povray.programming : Get polygon(or mesh) information Server Time: 27 Jun 2019 04:51:21 GMT
  Get polygon(or mesh) information (Message 1 to 4 of 4)  
From: tltsai
Subject: Get polygon(or mesh) information
Date: 24 Nov 2010 19:40:00
Message: <web.4ced693da22541bbd1585e400@news.povray.org>
Hello !

I create this image http://imgur.com/e6ICY.png .

1.For some reason, I want to know the information of polygons.These polygons are
on this cylinder and illuminated by reflex light from the ground.I want to know
information such as polygon coordinate , normal vector ...etc.

2.After I find those information,I want to change some properties of these
polygon,such as color or reflection.

So what source code I should modify to conquer above two questions?

Any suggestion would be OK!

Thanks a lot !

tltsai


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From: Le Forgeron
Subject: Re: Get polygon(or mesh) information
Date: 24 Nov 2010 20:10:39
Message: <4ced713f$1@news.povray.org>
Greetings,

Le 24/11/2010 20:36, tltsai nous fit lire :
> Hello !
> 
> I create this image http://imgur.com/e6ICY.png .
> 

A cylinder on flat box.

> 1.For some reason, I want to know the information of polygons.These polygons are
> on this cylinder and illuminated by reflex light from the ground.I want to know
> information such as polygon coordinate , normal vector ...etc.
> 

Huh ?
Which polygons ? The cylinder is not made of polygon, that's the
difference of Povray.

> 2.After I find those information,I want to change some properties of these
> polygon,such as color or reflection.
> 
> So what source code I should modify to conquer above two questions?

How did you make the image ?

> 
> Any suggestion would be OK!

A classical RTFM ? Might be a bit rude ?
A bit of direction about using trace() in your scene
Try the documentation at http://www.povray.org/


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From: Kenneth
Subject: Re: Get polygon(or mesh) information
Date: 26 Nov 2010 08:15:00
Message: <web.4cef6c2c7e9d33ca196b08580@news.povray.org>
It looks like your box and cylinder are POV-Ray 'primitive shapes'--meaning,
they are not polygons, but generated by POV-Ray from mathematical
functions--which means they have (almost) infinite precision, and you can get
closer and closer to them and they will still look smooth.

So there is no way to get 'polygon information' from such shapes.

POV-Ray doesn't 'create' polygon models (although there are exceptions--see
"shapes.inc", for example.) Polygon models are usually made in some other
modeling program, then imported into POV-Ray for rendering.

Ken


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From: Kenneth
Subject: Re: Get polygon(or mesh) information
Date: 27 Nov 2010 13:55:00
Message: <web.4cf10c727e9d33ca196b08580@news.povray.org>
"Kenneth" <kdw### [at] earthlinknet> wrote:

> POV-Ray doesn't 'create' polygon models (although there are exceptions--see
> "shapes.inc", for example.)

I forgot to mention POV-Ray's very useful height_field--it IS made of triangles,
but the 'polygon information' for it isn't available to the user.

Ken


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