As a newbie, this may seem like a strange question: Is there anyway to draw
an outline (say 1+ pixel) around objects while (possibly even after) drawing
them?  I know this seems contrary to what raytracing does (realistic
renderings), but I want to do the outline for effect.

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peter <cuj### [at] hotmailcom> wrote:
> As a newbie, this may seem like a strange question: Is there anyway to draw
> an outline (say 1+ pixel) around objects while (possibly even after) drawing
> them?

  No.

-- 
                                                          - Warp

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"Warp" <war### [at] tagpovrayorg> wrote in message
news:448f0ad3@news.povray.org...
> peter <cuj### [at] hotmailcom> wrote:
> > As a newbie, this may seem like a strange question: Is there anyway to
draw
> > an outline (say 1+ pixel) around objects while (possibly even after)
drawing
> > them?
>
>   No.
>
> -- 
>                                                           - Warp

But you can do some tricks, possibly above the knowledge of a self
proclaimed newbie. For instance, see Thibaut Jonckheere's recent "Edge macro
demo scene". Though it doesn't appear to be a general solution (requires
mesh objects?)

Also, did megapov have a edge detect postprocessing feature?

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Ross nous apporta ses lumieres en ce 13/06/2006 17:14:
> "Warp" <war### [at] tagpovrayorg> wrote in message
> news:448f0ad3@news.povray.org...
>> peter <cuj### [at] hotmailcom> wrote:
> draw
> drawing
>>   No.
>>
>> -- 
>>                                                           - Warp
> 
> But you can do some tricks, possibly above the knowledge of a self
> proclaimed newbie. For instance, see Thibaut Jonckheere's recent "Edge macro
> demo scene". Though it doesn't appear to be a general solution (requires
> mesh objects?)
> 
> Also, did megapov have a edge detect postprocessing feature?
> 
> 
> 
A possibility is to surround the objects that you want to outline with a very slightly
larger, 
transparent version of itself. That object is set to rgbt 1 pigment. The trick is to
use 
fade_distance <small value>, fade_color rgb 0 and fade_power 999. The fade_distance
must be very 
close, but larger, to the size difference, or thickness of the "shell".
Getting everything OK is prety tricky, as you can go from a nearly invisible shell to
an opaque one 
with some very small changes.
I've tried it and it CAN work at least in some cases. Almost impossible to set up when
the object 
have any reflection.

-- 
Alain
-------------------------------------------------
Communism: It's everybody's shit.

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Alain wrote:
 > A possibility is to surround the objects that you want to outline with
 > a very slightly larger, transparent version of itself. That object is
 > set to rgbt 1 pigment. The trick is to use fade_distance <small
 > value>,  fade_color rgb 0 and fade_power 999. The fade_distance must
 > be very close, but larger, to the size difference, or thickness of the
 > "shell".
 > Getting everything OK is prety tricky, as you can go from a nearly
 > invisible shell to an opaque one with some very small changes.
 > I've tried it and it CAN work at least in some cases. Almost
 > impossible to set up when the object have any reflection.

If you've already got the entire object in slightly larger size, it 
might suffice to use texture and interior_texture : a transparent 
texture, but a black interior_texture. Won't work that good for 
reflections though, probably only for objects as seen from the camera.

Regards,
Tim

-- 
aka "Tim Nikias"
Homepage: <http://www.nolights.de>

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Tim Nikias nous apporta ses lumieres en ce 13/06/2006 19:08:
> Alain wrote:
>  > A possibility is to surround the objects that you want to outline with
>  > a very slightly larger, transparent version of itself. That object is
>  > set to rgbt 1 pigment. The trick is to use fade_distance <small
>  > value>,  fade_color rgb 0 and fade_power 999. The fade_distance must
>  > be very close, but larger, to the size difference, or thickness of the
>  > "shell".
>  > Getting everything OK is prety tricky, as you can go from a nearly
>  > invisible shell to an opaque one with some very small changes.
>  > I've tried it and it CAN work at least in some cases. Almost
>  > impossible to set up when the object have any reflection.
> 
> If you've already got the entire object in slightly larger size, it 
> might suffice to use texture and interior_texture : a transparent 
> texture, but a black interior_texture. Won't work that good for 
> reflections though, probably only for objects as seen from the camera.
> 
> Regards,
> Tim
> 
Wont work for reflective or transparent objects. My solution does work with
transparent objects (as 
per my first succesful tests) and can potentialy works with reflective ones (but I
never managed to).

-- 
Alain
-------------------------------------------------
But I thought YOU did the backups...

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"Warp" <war### [at] tagpovrayorg> wrote in message 
news:448f0ad3@news.povray.org...
> peter <cuj### [at] hotmailcom> wrote:
>> As a newbie, this may seem like a strange question: Is there anyway to 
>> draw
>> an outline (say 1+ pixel) around objects while (possibly even after) 
>> drawing
>> them?
>
>  No.
>
> -- 
>                                                          - Warp

http://news.povray.org/povray.binaries.images/thread/%3C3d3edd19%40news.povray.org%3E/
http://news.povray.org/povray.binaries.images/thread/%3C3d3fd84f%40news.povray.org%3E/
http://news.povray.org/povray.text.scene-files/thread/%3C3d3eddb0%40news.povray.org%3E/

Warp likes to give up too easy ;)

He means "no you can't directly, but htere are options for post processing 
methods"

-tgq

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Wasn't it Ross who wrote:
>
>Also, did megapov have a edge detect postprocessing feature?

Yes, post_processing find_edges. But it's only in MegaPOV v0, it didn't
get carried forward into MegaPOV v1.

-- 
Mike Williams
Gentleman of Leisure

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Mike Williams wrote:
> Wasn't it Ross who wrote:
> 
>>Also, did megapov have a edge detect postprocessing feature?
> 
> 
> Yes, post_processing find_edges. But it's only in MegaPOV v0, it didn't
> get carried forward into MegaPOV v1.
> 


I think it survived in Megapov v1, it is now inside the  larger 
post-process macro. See 
http://megapov.inetart.net/manual-1.2.1/inc_pprocess.inc.html, "3.5.1.5. 
Finding edges"

Thibaut

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peter wrote:
> As a newbie, this may seem like a strange question: Is there anyway to draw
> an outline (say 1+ pixel) around objects while (possibly even after) drawing
> them?  I know this seems contrary to what raytracing does (realistic
> renderings), but I want to do the outline for effect.
> 
> 
To complete the answers and links given by the others, there are indeed 
some methods to get object outline. In addition to the links given by 
Trevor G Qayle, you can :

- use my edgemacro macro (I have posted the necessary includes recently 
in p.b.scene-files). It works nicely for any geometry, but is limited to 
mesh objects, and there is some work needed to be able to use it with a 
given object.

- use megapov "find edges" post process (see the link above, in the 
answer to Mike Williams). Works with any object and scene. Main weakness 
: really slow (even for very simple scene), and it is difficult to get 
rid of antialiasing for the outline

- use the "angle of incidence" technique (again requires megapov). This 
method is quite simple to implement, and works well for smooth round 
shapes, but it is difficult to get good results when you have more 
complex shapes. You can see a nice image made by Lightbeam with this 
technique at 
http://news.povray.org/povray.binaries.images/thread/%3C41f7e1ab@news.povray.org%3E/
with the scene-file at : 
http://news.povray.org/povray.binaries.scene-files/attachment/%3C41f9190a@news.povray.org%3E/us-ascii?ttop=216485&toff=50



Thibaut

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