As you can see it, this part of height-field is a bit too much
pixellised (we see big squares on the slopes). Unfortunately, when I use
a better defined grayscale image, I don't have enough memory to render
it.
Does someone have an idea ?


-- 
"Je ne deteste que les bourreaux" -- Albert Camus

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Attachments:
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Preview of image 'reve.jpg'

news:1g03c5r.1ugst2b961wgfN%PASDEPUBnoe.falzon@tiscali.fr...
> As you can see it, this part of height-field is a bit too much
> pixellised (we see big squares on the slopes). Unfortunately, when I use
> a better defined grayscale image, I don't have enough memory to render
> it.
> Does someone have an idea ?

Add the keyword 'smooth' to the HF statement. Other than higher resolution
that's about all I know to do (When I remember to use it myself! Long story,
recent event.)

Bob H.

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The smooth keyword sometimes helps, and sometimes doesn't. Often a
height-field needs to be generated in 16-bit to avoid artifacts (see pov-ray
documentation).

-Chris

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Buy some more memory or another computer ...  :-)

Apart from smooth keyword and using a higher resolution hf image, I 
don't see anything else.

Depending on the shape you want (btw, I couldn't read attached image) 
you can also try isosurfaces with adequate noise3D + f_granite for 
example. It takes more time to render but uses less memory. It's also 
perfectly smooth whatever the resolution.

JC


> As you can see it, this part of height-field is a bit too much
> pixellised (we see big squares on the slopes). Unfortunately, when I use
> a better defined grayscale image, I don't have enough memory to render
> it.
> Does someone have an idea ?
> 

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Noe:

Hmm ...  Are you already using the smooth keyword on this?
There is some rather odd artifacting going on.

I would actually turn smooth off and try to optimize the look
of the "mountain" using trees, texture, etc.  Toss a bunch of
green things on the naturally flat places.  Use a texture that has
a normal map containing different uses of granite at a larger
scale, for example.  Also, vary the color on the surface.

You can hide a lot of problems this way.

Aaron






news:1g03c5r.1ugst2b961wgfN%PASDEPUBnoe.falzon@tiscali.fr...
> As you can see it, this part of height-field is a bit too much
> pixellised (we see big squares on the slopes). Unfortunately, when I use
> a better defined grayscale image, I don't have enough memory to render
> it.
> Does someone have an idea ?
>

> --
> "Je ne deteste que les bourreaux" -- Albert Camus
>

>
>
>

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news:1g03c5r.1ugst2b961wgfN%PASDEPUBnoe.falzon@tiscali.fr...

| Does someone have an idea ?
|

Height-fields themselves are pretty half-455ed, and making one from an
image_map only adds another layer of half-455ness. I'm not suggesting
that your effort is in any way half-455ed. The image map you have
generated is quite nice, but even an isosurface created from an image
map is going to be jagged unless the image map is *huge*.

The first step towards getting a decent looking mountain will be to
describe a similar looking map with functions. That will solve your
resolution problems without using any memory. Once you have the
function, you can create an isosurface if you have the patience for it
to render.

If memory is a problem at all, then a high-resolution height-field like
this isn't going to leave much memory for additional elements in the
scene. Doesn't matter anyway, generalized algorithms like the
height-field give 5h!++y results, and increasing the resolution to
stupid levels only makes them somewhat less 5h!++y, not good. My
suggestion would be to create a medium resolution height-field and to
then add a granite or similar normal.

 -Shay

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Thanks for all your comments.
Actually, there is already the smooth keyword. I ill increase the
resolution of my greyscale image, even if I don't have enough memory to
render it ;)


-- 
"Je ne deteste que les bourreaux" -- Albert Camus

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I would offer to render it for you (I have 512 Mb memory), but my machine
is struggling through an image with lots of focal blur at the moment ...

> Actually, there is already the smooth keyword. I ill increase the
> resolution of my greyscale image, even if I don't have enough memory to
> render it ;)
>

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news:1g03tnq.ihl98hcm907bN%PASDEPUBnoe.falzon@tiscali.fr...

| I ill increase the
| resolution of my greyscale image, even if I don't have
| enough memory to render it ;)
|

*sigh* Another one gone over to brute force. You'll find that road
doesn't take you very far.

 -Shay

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These artifacts are caused by a bug in the height field smoothing algorithm.
Simply put, it causes flat areas to become "too flat" (vertical normals are
weighted more heavily than other normals). I discovered and fixed the bug in
Slime-POV ( http://www.slimeland.com/slimepov/ ), and I believe the fix made
it into MegaPov 1.0. In addition, I think the bugfix will be in POV-Ray
3.5.1, but there's no ETA on that right now.

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

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