POV-Ray : Newsgroups : povray.binaries.images : Bitmap To Prism Utility (Work In Progress) Server Time: 27 May 2017 07:59:49 GMT
  Bitmap To Prism Utility (Work In Progress) (Message 1 to 5 of 5)  
From: Dave Blandston
Subject: Bitmap To Prism Utility (Work In Progress)
Date: 18 Dec 2016 14:40:01
Message: <web.58569dbae3e0ec7c6ae7df010@news.povray.org>
Hello,

I have posted a Bitmap to Prism conversion utility WIP in the binaries.utilities
section. Everything is done except the actual control point generation (the hard
part).

This image shows a bitmap image being processed. In this picture, the red pixels
indicate the shape that will be converted to a prism object. The contrasting
cyan dots just show which pixels have been identified as the shape to be
converted and prove that everything is working up to this point in the project.
The important output from this program will be a text file containing prism
control points.

I'm stymied regarding the process of automatically generating control points for
cubic_spline prisms. So if anyone has any suggestions regarding that process
please let me know.

Regards,
Dave Blandston


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Attachments:
Download 'prismdatagenerator.png' (35 KB)

Preview of image 'prismdatagenerator.png'
prismdatagenerator.png


 

From: Dave Blandston
Subject: Re: Bitmap To Prism Utility (Work In Progress)
Date: 18 Dec 2016 14:50:01
Message: <web.5856a09a4d4e4daa6ae7df010@news.povray.org>
This picture shows the original bitmap with a cubic_spline prism overlay.
Unfortunately, the control points for this prism were made by hand just to test
the utility program.

The yellow dots indicate control points.

Regards,
Dave Blandston


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Attachments:
Download 'prismdatafiledemo.png' (27 KB)

Preview of image 'prismdatafiledemo.png'
prismdatafiledemo.png


 

From: Paolo Gibellini
Subject: Re: Bitmap To Prism Utility (Work In Progress)
Date: 19 Dec 2016 08:46:20
Message: <58579e5c$1@news.povray.org>
Dave Blandston wrote on 18/12/2016 15:36:
> Hello,
>
> I have posted a Bitmap to Prism conversion utility WIP in the binaries.utilities
> section. Everything is done except the actual control point generation (the hard
> part).
>
> This image shows a bitmap image being processed. In this picture, the red pixels
> indicate the shape that will be converted to a prism object. The contrasting
> cyan dots just show which pixels have been identified as the shape to be
> converted and prove that everything is working up to this point in the project.
> The important output from this program will be a text file containing prism
> control points.
>
> I'm stymied regarding the process of automatically generating control points for
> cubic_spline prisms. So if anyone has any suggestions regarding that process
> please let me know.
>
> Regards,
> Dave Blandston
>

A prism version of a bump-map?
Seems interesting,
    Paolo


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From: William F Pokorny
Subject: Re: Bitmap To Prism Utility (Work In Progress)
Date: 19 Dec 2016 14:30:25
Message: <5857ef01$1@news.povray.org>
On 12/18/2016 09:45 AM, Dave Blandston wrote:
> This picture shows the original bitmap with a cubic_spline prism overlay.
> Unfortunately, the control points for this prism were made by hand just to test
> the utility program.
>
> The yellow dots indicate control points.
>
> Regards,
> Dave Blandston
>
Interesting.

Have you tested the on curve point generation for substantially concave 
bitmaps - 'C' like shapes?

How about bitmaps with holes - 'O' like shapes?

As for control points and alignment with results from other tools wonder 
if the bezier_spline might not be the way to go.

---
Aside 1 : A while back I started a project with the idea of providing an 
POV-Ray version of the bit mapped Unifont. See:

https://en.wikipedia.org/wiki/GNU_Unifont

Idea was to provide a bitmap from the unifont directly, a set of inside 
paths/curves and an outer bezier_curve for all the characters in the 
unifont as POV-Ray include files. People on the planet could then do 
what ever they wanted with the data inside or outside of POV-Ray with 
useful character shape data. I got started on it with a 64x64 base 
bitmap in POV-Ray, but then got distracted; One of my bad habits.

Aside 2: There is in the POV-Ray objects collection off the main page a 
PointArrays package by bherring/BlueHerring (Matthew Goulet) for 
manipulating curves. One of the macros is PA_Linear_To_Bezier() and 
there is a demo for it in: pa_linear_to_bezier_demo.pov.

Aside 3: There is too an interesting general polygon / path manipulation 
tool in : http://www.angusj.com/delphi/clipper.php which I thought might 
be useful to - even as a general in POV-Ray SDL set of features.

Anyway, your tool would likely fit with such an all plane 0 characters 
in various POV-Ray formats effort - so I'm interested.

Bill P.


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From: Dave Blandston
Subject: Re: Bitmap To Prism Utility (Work In Progress)
Date: 21 Dec 2016 17:20:00
Message: <web.585ab9764d4e4daa6ae7df010@news.povray.org>
William F Pokorny <ano### [at] anonymousorg> wrote:
> Have you tested the on curve point generation for substantially concave
> bitmaps - 'C' like shapes?

I'm going to attempt a solution for arbitrary shapes.

> How about bitmaps with holes - 'O' like shapes?

Holes are not a problem. The prism object already supports holes and the code
I've written so far specifically supports this feature.

> As for control points and alignment with results from other tools wonder
> if the bezier_spline might not be the way to go.

Agreed, but bezier curves are FAR beyond my math skills. It occurred to me that
the Inkscape code is open source and I could study how it vectorizes bitmaps,
but once again the math and coding are way out of my league.

> Aside 2: There is in the POV-Ray objects collection off the main page a
> PointArrays package by bherring/BlueHerring (Matthew Goulet) for
> manipulating curves. One of the macros is PA_Linear_To_Bezier() and
> there is a demo for it in: pa_linear_to_bezier_demo.pov.
>
> Aside 3: There is too an interesting general polygon / path manipulation
> tool in : http://www.angusj.com/delphi/clipper.php which I thought might
> be useful to - even as a general in POV-Ray SDL set of features.

These might be helpful. Thanks for passing this info on.

Regards,
Dave Blandston


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