Hi,  (Do you know of any hidden line rendering api?)

I wonder what do I need to do to get renderings like this from povray?
(I'm afraid, ,it's not possible in pov)
http://www.kitchendesigned.com/tmp/hidden_line.jpg

let me pose the question this way too,
what software do you know of that does this(hidden line rendering)?
I dont mean ready software like(3dmax, etc). I mean api or plugin or whatever
but I need to do this from within my own C# application either thru Povray or
any other software that will do the job.

I have been stuck on this too for a couple of years now. The internet is poor on
this subject or I couldn't ask the correct questions. I'm afraid this won't be
easy and I will have to learn a whole new set of api such as povray or opengl...

I really appreciate any input you can provide.

Thank you
optima

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optima wrote:
> but I need to do this from within my own C# application either thru Povray or
> any other software that will do the job.

Have you looked into XNA? What sort of result do you need? You could build a 
3D model and a shader that would give you just the outlines of things, then 
capture the image from the render buffer.

-- 
Darren New, San Diego CA, USA (PST)
   Serving Suggestion:
     "Don't serve this any more. It's awful."

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Darren New <dne### [at] sanrrcom> wrote:
> Have you looked into XNA? What sort of result do you need? You could build a
> 3D model and a shader that would give you just the outlines of things, then
> capture the image from the render buffer.
>

Hi Darren,

I looked into xna last year as far as I know it stands on the same viewpoint as
povray on hiddenlines issue. Not possible or possible easily.

If I can use a shader in xna that can show 3d objects only as hidden lines
then problem is solved(almost). Cause I am already familiar with xna.

There must be some other way, what is autocad, 3ds max using to make hidden line
renders possible? I mean what technology, as in we use povray to get quality
still
pictures of 3d models.


thank you very much
optima

PS: I dont mean wireframe, it's something else.

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optima wrote:
> If I can use a shader in xna that can show 3d objects only as hidden lines
> then problem is solved(almost). Cause I am already familiar with xna.

It's not hard. draw the background in white. Draw the model with clockwise 
culling in black. Draw the model scaled down 2% in white with 
counterclockwise culling. Ta dah. :-)

I'm not sure what you mean by "hidden lines" renders, tho. Do you meen just 
drawing the edges, like your sample picture? Because hidden lines per se is 
pretty easy and already done with painter's algorithm, pov-ray, or any 
graphics card with a depth buffer.

Alternately, draw the model as a depth map and then run it through an edge 
detector algorithm? Again, I'm not sure what you mean by hidden lines.

The phrase you're looking for might be "cel shading", (or cell shading) 
which means a cartoon-like flat-colors look to the image.

http://create.msdn.com/en-US/education/catalog/sample/nonrealistic_rendering

It can make images like this?

http://create.msdn.com/assets/cms/images/XNA_NonRealisticRendering_02_large.jpg


-- 
Darren New, San Diego CA, USA (PST)
   Serving Suggestion:
     "Don't serve this any more. It's awful."

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> Darren New<dne### [at] sanrrcom>  wrote:
>> Have you looked into XNA? What sort of result do you need? You could build a
>> 3D model and a shader that would give you just the outlines of things, then
>> capture the image from the render buffer.
>>
>
> Hi Darren,
>
> I looked into xna last year as far as I know it stands on the same viewpoint as
> povray on hiddenlines issue. Not possible or possible easily.
>
> If I can use a shader in xna that can show 3d objects only as hidden lines
> then problem is solved(almost). Cause I am already familiar with xna.
>
> There must be some other way, what is autocad, 3ds max using to make hidden line
> renders possible? I mean what technology, as in we use povray to get quality
> still
> pictures of 3d models.
>
>
> thank you very much
> optima
>
> PS: I dont mean wireframe, it's something else.
>
>
>
>

Those mostly use triangles/polys that are coloured as the background 
with the edges set to some colour. Then, using the Z-buffer, draw them 
starting with the farthest ones.
There is additional computation that can be done to hide lines that are 
inside the contour of the geometry.


Alain

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optima wrote:
> Hi,  (Do you know of any hidden line rendering api?)

Also, in POV-Ray, I believe the AOI pattern could give it to you. Also, 
someone earlier posted a texture that made things look like you were 
photographing them through an electron microscope.

So, basically, if you find a pattern in POV-Ray that changes a texture map 
based on the angle between the normal and the camera ray, it should be 
pretty easy to draw everything white except that which exceeds some angle, 
and get an image like your teapot.

-- 
Darren New, San Diego CA, USA (PST)
   Serving Suggestion:
     "Don't serve this any more. It's awful."

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On 12/21/2010 08:42 PM, optima wrote:
> Hi,  (Do you know of any hidden line rendering api?)
>
> I wonder what do I need to do to get renderings like this from povray?
> (I'm afraid, ,it's not possible in pov)
> http://www.kitchendesigned.com/tmp/hidden_line.jpg
>

Check edgeFinder.pov for MegaPOV at
http://news.povray.org/povray.text.scene-files/thread/%3C4c1beb00@news.povray.org%3E/

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Thank you for all the answers,

By hidden lines I mean only the outline of geometry drawn as seen in the teapot
picture. in black lines with white background.

Will AOI patter work as Darren suggested?

Bart didn' include the path to his suggestion,
Check edgeFinder.pov for MegaPOV at ??

Alain, can you show a sample on a simple box as to how your suggestion could be
implemented?

Appreciate all the help,

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Am 23.12.2010 10:01, schrieb optima:
> Thank you for all the answers,
>
> By hidden lines I mean only the outline of geometry drawn as seen in the teapot
> picture. in black lines with white background.
>
> Will AOI patter work as Darren suggested?

That depends. If your objects do not have any sharp edges, it will work. 
It will not capture sharp edges though, such as the outline of a box.

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clipka <ano### [at] anonymousorg> wrote:
> It will not capture sharp edges though, such as the outline of a box.

It must especially capture the edges of a box, because mostly it will be used to
outline the edges of a kitchen design which is basically made of boxes
representing cabinets.

I dont understand how other kitchen design applications do it. Cause all
interior design apps I saw have different viewing modes. One of them is
hiddenlines(at least 20-20 calls it that, it may have other names too).

http://www.kitchendesigned.com/tmp/textured_render.jpg

http://www.kitchendesigned.com/tmp/hidden_line_render.jpg

thank you

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