POV-Ray : Newsgroups : povray.general : heightfield + f_ridged_mf Server Time
29 Nov 2024 13:45:51 EST (-0500)
  heightfield + f_ridged_mf (Message 1 to 3 of 3)  
From: gvdeynde
Subject: heightfield + f_ridged_mf
Date: 18 Oct 2005 14:32:15
Message: <43553faf$1@news.povray.org>
Hi,

Can anyone help me in setting up a large xz heighfield (x,z scale about 1e8, 
y scale small about 20)? I've tried a reasonable size (x,z scale about 1e3) 
with values for the different parameters that I found at Christoff Hormann's 
page and that works nicely. However, when increasing the xz-scale, the 
heightfield flattens out and I don't know how to get small (xz size about 
100, y height about 20) bumps in such a large heightfield. If anyone could, 
in laymen's terms, explain the parameters for me a bit more than what is 
written in the manual, that might come in handy too ;-)

thanks,
gert


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From: Slime
Subject: Re: heightfield + f_ridged_mf
Date: 18 Oct 2005 14:54:35
Message: <435544eb$1@news.povray.org>
If your height field is 1e8x1e8 units wide and only 20 units tall, then
you'll have to have a huge resolution (around the scale of 1e8 by 1e8) to
get bumps at a small scale. You don't want a height field at that
resolution; you don't have the memory for it.

Try one of these options instead:

 - Use an isosurface. Since it's sampled dynamically, you get perfect
resolution at any scale. However, it will be slower.
 - Use multiple height fields at different resolutions, some close up and
high resolution, others farther away at lower resolutions.

If your camera is close enough to the height field to need to see bumps at a
scale of 20 units or so, then you don't need your height field to be 1e8
units wide; that's overkill.

 - Slime
 [ http://www.slimeland.com/ ]


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From: Gert  Van den Eynde
Subject: Re: heightfield + f_ridged_mf
Date: 20 Oct 2005 05:45:06
Message: <43576722@news.povray.org>
Slime wrote:

> If your height field is 1e8x1e8 units wide and only 20 units tall, then
> you'll have to have a huge resolution (around the scale of 1e8 by 1e8) to
> get bumps at a small scale. You don't want a height field at that
> resolution; you don't have the memory for it.

thanks. realised that now. I've used a reasonably sized HF with an
underlying plane for the far away regions... 

bye,
gert


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