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14 Aug 2024 22:22:42 EDT (-0400)
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From: Norbert Kern
Subject: Re: varnish test
Date: 9 Oct 2002 08:05:06
Message: <web.3da41a86ea2d989a736664ab0@news.povray.org>
Christoph Hormann wrote:
>
>I'm not sure if i understand this right, you use a slope pattern in
>direction of the main light to texture the side facing the light with some
>normal plant texture and the other side with an ambient finish to simulate
>the light scattered?


the grass pigment has a slope pattern in the direction cam_pos to look_at.
Color is nearly orange with sides facing the camera and dark green with
perpendicular sides. So this is a total fake.
Flower blossoms have double_illuminate and a slope pattern regarding
transparency in the direction cam_pos to lightsource position. So every
blossom looks a little different. This is a better simulation of nature I
think.



>Your scene, although being impressive by the sheer amount of plants, seems
>to lack the contrast in the colors you usually would expect for a view
>against the light.
>A scene showing this quite well is:
>http://marc.jacquier.free.fr/pen_ar_bed_herb.htm



You are right, first it was a test scene for memory load reduction in grass
scenes.


to a scene because of the lacking contrast. This is because the sun is not
near the horizont, the heightfield is fairly flat and to reduce memory load
only a simple texture for the whole grass mesh is used. With
double_illuminate the situation was even worse. Contrast is higher in the
original 2560*1920 render.


addition the contrast within the grass near the lighthouse seems to come
mainly from jpeg artifacts.
In my holidays I studied back light scenes in nature and your link seems not
very near to anything I have seen in sweden.


Norbert


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From: Norbert Kern
Subject: Re: varnish test
Date: 9 Oct 2002 16:05:27
Message: <3da48c07@news.povray.org>
here are two small partial renders of my last grass scene.
The first one is with slope dependent pigments in the grass and the
blossoms,
the second has only averaged simple pigments.

In my opinion the first one has much more contrast as the second.


Norbert


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Attachments:
Download 'slope_pigments.jpg' (45 KB) Download 'without_slope_pigments.jpg' (45 KB)

Preview of image 'slope_pigments.jpg'
slope_pigments.jpg

Preview of image 'without_slope_pigments.jpg'
without_slope_pigments.jpg


 

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