Hi(gh)!

Meanwhile, I generated the first global physical maps of Whatmough (see 
also my posting in p.b.a), starting with the terrain relief and land/see 
distribution as shown in the animation (first image attached)... as 
ocean depths and land heights were still too extreme for an almost 
Earth-sized body, I tweaked the scaling factor of the terrain function 
as well as the sea level (second image). But still I'm not contented 
with the result, as low-lying land areas (dark and light green) and 
shallow continental shelves (pale cyan) are by far too narrow to look 
Earth-like. Which parameter(s) of the ridged_mf() function do I have to 
change to achieve this?

See you in Khyberspace!

Yadgar

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Preview of image '2018-02-12 global map of whatmough, take 1.png'

Preview of image '2018-02-13 global map of whatmough, take 4.png'

On 13/02/2018 09:21, Jörg "Yadgar" Bleimann wrote:
> Hi(gh)!
> 
> Meanwhile, I generated the first global physical maps of Whatmough (see 
> also my posting in p.b.a), starting with the terrain relief and land/see 
> distribution as shown in the animation (first image attached)... as 
> ocean depths and land heights were still too extreme for an almost 
> Earth-sized body, I tweaked the scaling factor of the terrain function 
> as well as the sea level (second image). But still I'm not contented 
> with the result, as low-lying land areas (dark and light green) and 
> shallow continental shelves (pale cyan) are by far too narrow to look 
> Earth-like. Which parameter(s) of the ridged_mf() function do I have to 
> change to achieve this?
> 


Run a series of animations changing one variable at a time.
That should give you a better idea where to start if you want to refine it.

-- 

Regards
     Stephen

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On 13-2-2018 10:21, Jörg "Yadgar" Bleimann wrote:
> Hi(gh)!
> 
> Meanwhile, I generated the first global physical maps of Whatmough (see 
> also my posting in p.b.a), starting with the terrain relief and land/see 
> distribution as shown in the animation (first image attached)... as 
> ocean depths and land heights were still too extreme for an almost 
> Earth-sized body, I tweaked the scaling factor of the terrain function 
> as well as the sea level (second image). But still I'm not contented 
> with the result, as low-lying land areas (dark and light green) and 
> shallow continental shelves (pale cyan) are by far too narrow to look 
> Earth-like. Which parameter(s) of the ridged_mf() function do I have to 
> change to achieve this?
> 
> See you in Khyberspace!
> 
> Yadgar

I would say that the continental shelf width is ok; the land heights 
have a problem indeed.

I may have a solution, but I need to delve deep into my (planetary) 
scene files, so patience.

-- 
Thomas

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On 13-2-2018 13:44, Thomas de Groot wrote:
> On 13-2-2018 10:21, Jörg "Yadgar" Bleimann wrote:
>> Hi(gh)!
>>
>> Meanwhile, I generated the first global physical maps of Whatmough 
>> (see also my posting in p.b.a), starting with the terrain relief and 
>> land/see distribution as shown in the animation (first image 
>> attached)... as ocean depths and land heights were still too extreme 
>> for an almost Earth-sized body, I tweaked the scaling factor of the 
>> terrain function as well as the sea level (second image). But still 
>> I'm not contented with the result, as low-lying land areas (dark and 
>> light green) and shallow continental shelves (pale cyan) are by far 
>> too narrow to look Earth-like. Which parameter(s) of the ridged_mf() 
>> function do I have to change to achieve this?
>>
>> See you in Khyberspace!
>>
>> Yadgar
> 
> I would say that the continental shelf width is ok; the land heights 
> have a problem indeed.
> 
> I may have a solution, but I need to delve deep into my (planetary) 
> scene files, so patience.
> 

Sorry, no luck. I build my planets using a planetary image_map as 
function. That is a different approach.

I keep looking for scenes where I might have used ridged_mf(); I know I 
have, but it is a needle in a haystack of code...

-- 
Thomas

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On 2/13/2018 4:21 AM, Jörg "Yadgar" Bleimann wrote:
> Hi(gh)!
> 
> Meanwhile, I generated the first global physical maps of Whatmough (see 
> also my posting in p.b.a), starting with the terrain relief and land/see 
> distribution as shown in the animation (first image attached)... as 
> ocean depths and land heights were still too extreme for an almost 
> Earth-sized body, I tweaked the scaling factor of the terrain function 
> as well as the sea level (second image). But still I'm not contented 
> with the result, as low-lying land areas (dark and light green) and 
> shallow continental shelves (pale cyan) are by far too narrow to look 
> Earth-like. Which parameter(s) of the ridged_mf() function do I have to 
> change to achieve this?
> 
> See you in Khyberspace!
> 
> Yadgar


I think what you need is some erosion to smooth some of the sharp edges. 
Dunno how to do that though.

Mike

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Mike Horvath <mik### [at] gmailcom> wrote:

> I think what you need is some erosion to smooth some of the sharp edges.
> Dunno how to do that though.

A macro or libray that allowed us to do offset-curves, or Minkowski Sums would
accomplish that if he were using a mesh.

http://www3.cs.stonybrook.edu/~algorith/files/minkowski-sum.shtml

Perhaps if he added or subtracted a bit of Perlin noise from the function, it
would accomplish some [random] smoothing of the function.

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On 2/15/2018 12:23 PM, Bald Eagle wrote:
> Mike Horvath <mik### [at] gmailcom> wrote:
> 
>> I think what you need is some erosion to smooth some of the sharp edges.
>> Dunno how to do that though.
> 
> A macro or libray that allowed us to do offset-curves, or Minkowski Sums would
> accomplish that if he were using a mesh.
> 
> http://www3.cs.stonybrook.edu/~algorith/files/minkowski-sum.shtml
> 
> Perhaps if he added or subtracted a bit of Perlin noise from the function, it
> would accomplish some [random] smoothing of the function.
> 

Well, I meant realistic weather and coastline erosion. I've played 
around with World Machine in the past, but have no clue how to translate 
those methods into POV-Ray.


Mike

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Hi(gh)!

On 15.02.2018 17:15, Mike Horvath wrote:

> I think what you need is some erosion to smooth some of the sharp edges. 
> Dunno how to do that though.

You probably refer to the sharp contour boundaries in the maps - but 
this is just an artifact of coloring defined height ranges (e. g. 0 to 
100 metres = dark green, 100 to 200 metres = light green and so on). 
With the real isosurface, there are still smooth transitions in height!

See you in Khyberspace!

Yadgar

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On 14-2-2018 9:16, Thomas de Groot wrote:
> On 13-2-2018 13:44, Thomas de Groot wrote:
>> On 13-2-2018 10:21, Jörg "Yadgar" Bleimann wrote:
>>> Hi(gh)!
>>>
>>> Meanwhile, I generated the first global physical maps of Whatmough 
>>> (see also my posting in p.b.a), starting with the terrain relief and 
>>> land/see distribution as shown in the animation (first image 
>>> attached)... as ocean depths and land heights were still too extreme 
>>> for an almost Earth-sized body, I tweaked the scaling factor of the 
>>> terrain function as well as the sea level (second image). But still 
>>> I'm not contented with the result, as low-lying land areas (dark and 
>>> light green) and shallow continental shelves (pale cyan) are by far 
>>> too narrow to look Earth-like. Which parameter(s) of the ridged_mf() 
>>> function do I have to change to achieve this?
>>>
>>> See you in Khyberspace!
>>>
>>> Yadgar
>>
>> I would say that the continental shelf width is ok; the land heights 
>> have a problem indeed.
>>
>> I may have a solution, but I need to delve deep into my (planetary) 
>> scene files, so patience.
>>
> 
> Sorry, no luck. I build my planets using a planetary image_map as 
> function. That is a different approach.
> 
> I keep looking for scenes where I might have used ridged_mf(); I know I 
> have, but it is a needle in a haystack of code...
> 

Maybe this is of help. Do you remember my Geomorph macro from about 10 
years ago? It models an isosurface landscape but the principles are 
identical for a planet as the same functions are used. If you do not 
have the macro, I attach here the latest version with the documentation. 
Both are compatible even if the macro versions mentioned in the docs are 
different. There is a short description of the ridged_mf function where 
the parameter 'offset' might be what you are looking for. Otherwise, I 
must say that Geomorph is a monster ;-)

I hope you can make sense of it and extract useful snippets for your 
project.

-- 
Thomas

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