POV-Ray : Newsgroups : povray.general : 2D image of parsing : Re: 2D image of parsing Server Time: 29 Oct 2020 22:55:26 GMT
  Re: 2D image of parsing  
From: Bald Eagle
Date: 14 Aug 2020 20:05:00
"Kima" <nomail@nomail> wrote:
> This question is not practical, and I just want to better understand POV-RAY!

Read the docs, and posts by clipka.

> As I understand, POV-RAY calculates the location and texture of objects during
> the PARSING process. Then, in the RENDERING process, calculates the colour of
> each pixel by raytracing.

My limited understanding of the overall process from reading and peeking through
the source code is this:
Parsing essentially collects all of the definitions of the objects and textures
and lighting for processing during the render phase.
After all of the SDL has been read and stored in memory as some sort of
mathematical representation, or data structure as Jerome pointed out, then
POV-Ray sets about performing the CPU intensive task of shooting a ray from the
camera out to the top left pixel, determining if there is a ray-object
intersection, if there is a reflection, if there is a shadow, and compositing
all of those contributing factors with the texture and finish of any surface to
determine the final rgb value of that pixel.

You can certainly find plenty of documents, articles, videos and books on
raytracing in general.

> I wonder if it is possible to calculate the pixels after the parsing process?

vide supra

> The result should be a 2D image of the 3D scene, as no light is applied.

If no light is applied, you get a black rectangle.
Ask me how I know.   :D

> For example, a sphere should be seen as a plain circle.

That depends on the camera view.  Perspective distortion will rarely give a
circle.

https://www.shadertoy.com/view/XdBGzd

Highlights and shadows will provide visual cues to make the scene look 3D.  The
absence of any of that will make the scene look flat.

If you are _trying_ to produce a very flat scene or a silhouette or outline,
then there are various ways of going about that.


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