Hello everyone! Here's an idea I've been thinking of for quite a while. 
I'm pretty sure somebody has done something like this before... it might 
have been a grass texture, though.

What you see is actually a flat plane layered with over eighty 
semitransparent textures. Each additional texture is scaled slightly 
larger than the last, and uses a slightly altered color_map (actually a 
pigment_map, but it doesn't really need to be one anymore). The texture 
is then translated to the camera's X & Z coordinates to achieve a more 
proper illusion.

I can't really see a practical application for this trick. Even though 
this image rendered in a little over five minutes, it can get very slow 
when antialiasing is applied :(  Also, POV-Ray tends to throw an error 
if the number of texture layers goes over 100.

I still have yet to try it with radiosity. There's no reason why it 
shouldn't work.

The code has been placed (a little too hastily) to 
povray.binaries.scene-images.

Questions and comments are always welcome-

-Samuel Benge

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Attachments:
Download 'fake_elevation.jpg' (35 KB)

Preview of image 'fake_elevation.jpg'

Samuel Benge wrote:

> I can't really see a practical application for this trick. Even though 
> this image rendered in a little over five minutes, it can get very slow 
> when antialiasing is applied :(


Update:
I just tried it again with antialising, and the render time didn't 
really go up that much. Evidently, the last time I tried aa the texture 
had a lot of noise in it. Also, removing the surface normal considerably 
decreases render time.

I attached two more images. The first one has the surface normal in 
place and uses aa. The second uses no surface normal, but still has aa. 
The render times are diplayed in the lower right corner of each image.

-Samuel Benge

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Attachments:
Download 'fake_ev1.jpg' (15 KB) Download 'fake_ev2.jpg' (16 KB)

Preview of image 'fake_ev1.jpg'

Preview of image 'fake_ev2.jpg'

> I attached two more images. The first one has the surface normal in
> place and uses aa. The second uses no surface normal, but still has aa.
> The render times are diplayed in the lower right corner of each image.

Number two looks better (IMHO) and renders faster. Looks like a winner to
me.

Nice technique, BTW.

Regards!

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Uzytkownik "Samuel Benge" <stb### [at] hotmailcom> napisal w wiadomosci
news:407### [at] hotmailcom...
> Hello everyone! Here's an idea I've been thinking of for quite a while.
> I'm pretty sure somebody has done something like this before... it might
> have been a grass texture, though.
>
> What you see is actually a flat plane layered with over eighty
> semitransparent textures. Each additional texture is scaled slightly
> larger than the last, and uses a slightly altered color_map (actually a
> pigment_map, but it doesn't really need to be one anymore). The texture
> is then translated to the camera's X & Z coordinates to achieve a more
> proper illusion.
>
> I can't really see a practical application for this trick. Even though
> this image rendered in a little over five minutes, it can get very slow
> when antialiasing is applied :(  Also, POV-Ray tends to throw an error
> if the number of texture layers goes over 100.

It may come handy at rendering backdrops to aerial scenery (e.g. a flying
aeroplane).

>
> I still have yet to try it with radiosity. There's no reason why it
> shouldn't work.
>
> The code has been placed (a little too hastily) to
> povray.binaries.scene-images.
>
> Questions and comments are always welcome-
>
> -Samuel Benge
>

Respectfully

Matt


----------------------------------------------------------------------------
----

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Samuel Benge wrote:

> Hello everyone! Here's an idea I've been thinking of for quite a while. 
> I'm pretty sure somebody has done something like this before... it might 
> have been a grass texture, though.

<snip:technical />

BRILLIANT idea! It may cause some challenges for the renderer if objects 
  are within those planes. Have you found any trouble with, say, a 
sphere in the middle of the clouds?
-- 
Respectfully,
Dan P
http://<broken link>

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Samuel Benge nous apporta ses lumieres ainsi en ce 2004/04/08 15:33... :

> Samuel Benge wrote:
>
>> I can't really see a practical application for this trick. Even 
>> though this image rendered in a little over five minutes, it can get 
>> very slow when antialiasing is applied :(
>
>
>
> Update:
> I just tried it again with antialising, and the render time didn't 
> really go up that much. Evidently, the last time I tried aa the 
> texture had a lot of noise in it. Also, removing the surface normal 
> considerably decreases render time.
>
> I attached two more images. The first one has the surface normal in 
> place and uses aa. The second uses no surface normal, but still has 
> aa. The render times are diplayed in the lower right corner of each 
> image.
>
> -Samuel Benge
>
>
>
>
> ------------------------------------------------------------------------
>
>
> ------------------------------------------------------------------------
>
Second one looks beter for a flyby over some clouds, the first should be 
beter for a snowy field. For me anyway.

Alain

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In article <4075d862$1@news.povray.org>,
 Dan P <dan### [at] yahoocom> wrote:

> BRILLIANT idea! It may cause some challenges for the renderer if objects 
>   are within those planes. Have you found any trouble with, say, a 
> sphere in the middle of the clouds?

Well, since it's on a 2D surface, it'd look a bit odd...

BTW, I vaguely recall some very good sky_sphere pigments done using this 
technique. One advantage there is that you don't have any intersection 
or finish/normal calculations, so it renders faster. The layered pigment 
feature of sky_spheres seems to be overlooked far too much.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/

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Christopher James Huff wrote:

> In article <4075d862$1@news.povray.org>,
>  Dan P <dan### [at] yahoocom> wrote:
> 
> 
>>BRILLIANT idea! It may cause some challenges for the renderer if objects 
>>  are within those planes. Have you found any trouble with, say, a 
>>sphere in the middle of the clouds?
> 
> 
> Well, since it's on a 2D surface, it'd look a bit odd...
> 
> BTW, I vaguely recall some very good sky_sphere pigments done using this 
> technique. One advantage there is that you don't have any intersection 
> or finish/normal calculations, so it renders faster. The layered pigment 
> feature of sky_spheres seems to be overlooked far too much.

I misunderstood what he did; I thought he used many planes with seperate 
transparent image_maps. I should have looked at the source; my bad.

-- 
Respectfully,
Dan P
http://<broken link>

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Christopher James Huff wrote:

> BTW, I vaguely recall some very good sky_sphere pigments done using this 
> technique. One advantage there is that you don't have any intersection 
> or finish/normal calculations, so it renders faster. The layered pigment 
> feature of sky_spheres seems to be overlooked far too much.


Looks like something I'll have to try. Thanks.

-Samuel Benge

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"Samuel Benge" <stb### [at] hotmailcom> wrote in message
news:407### [at] hotmailcom...

> I can't really see a practical application for this trick. Even though
> this image rendered in a little over five minutes, it can get very slow
> when antialiasing is applied :(  Also, POV-Ray tends to throw an error
> if the number of texture layers goes over 100.
>

> -Samuel Benge
>

*drool* Practical applications are overrated and can alwasy come later :)
this alone is cool.

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