Hello, there is a program that can make bicubic patches for Povray?

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On 31/03/2025 00:39, gulino wrote:
> Hello, there is a program that can make bicubic patches for Povray?
> 

I am not sure about bicubic patches, but Blender has a reach editor
and supports Povray:
https://docs.blender.org/manual/en/4.1/addons/render/povray.html
-- 
YB

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On 31/03/2025 00:39, gulino wrote:
> Hello, there is a program that can make bicubic patches for Povray?
> 

I am not sure about bicubic patches, but Blender has a rich editor
and supports Povray:
https://docs.blender.org/manual/en/4.1/addons/render/povray.html

Also you can check my plugin for C4D, if you have one:
https://github.com/syanenko/cinema2pov
-- 
YB

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Am 30.03.2025 um 23:39 schrieb gulino:
> Hello, there is a program that can make bicubic patches for Povray?
> 

Please look at the discussion in:

https://news.povray.org/povray.binaries.images/thread/%3Cweb.67368d2782bd3fc14c71940bedfc8715%40news.povray.org%3E/

Best regaqrds
Michael

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"gulino" <nomail@nomail> wrote:
> Hello, there is a program that can make bicubic patches for Povray?

I guess also the question(s) should be - how many patches do you need to model,
and what is your goal?  Do you need to interactively model the patches, or do
you need to have the patches pass through certain points?

Can you use heightfields?

If you can use heightfields or functions, then you can craft the heightfields
using SDL in POV-Ray itself.

- BW

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"Bald Eagle" <cre### [at] netscapenet> wrote:
> "gulino" <nomail@nomail> wrote:
> > Hello, there is a program that can make bicubic patches for Povray?
>
> I guess also the question(s) should be - how many patches do you need to model,
> and what is your goal?  Do you need to interactively model the patches, or do
> you need to have the patches pass through certain points?
>
> Can you use heightfields?
>
> If you can use heightfields or functions, then you can craft the heightfields
> using SDL in POV-Ray itself.
>
> - BW

I want to make a plain like this image, I think heightfields will not work
because it's for mountains. I am not sure how many patches but for sure more
than one. It would be nice if there is a program that for example can make these
and give me the value of the points because it seems very hard doing by hand

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Preview of image 'planice.jpg'

"gulino" <nomail@nomail> wrote:

> I want to make a plain like this image, I think heightfields will not work
> because it's for mountains. I am not sure how many patches but for sure more
> than one. It would be nice if there is a program that for example can make these
> and give me the value of the points because it seems very hard doing by hand

I would think that a heightfield would be perfectly fine for that.

You can model anything from a perfectly flat plane to a very rough mountainous
terrain with a detailed enough heightfield.

But if you want to do the Bezier patches - that's a topic we can get into in
more detail.

- BW

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"Bald Eagle" <cre### [at] netscapenet> wrote:
> "gulino" <nomail@nomail> wrote:
>
> > I want to make a plain like this image, I think heightfields will not work
> > because it's for mountains. I am not sure how many patches but for sure more
> > than one. It would be nice if there is a program that for example can make these
> > and give me the value of the points because it seems very hard doing by hand
>
> I would think that a heightfield would be perfectly fine for that.
>
> You can model anything from a perfectly flat plane to a very rough mountainous
> terrain with a detailed enough heightfield.
>
> But if you want to do the Bezier patches - that's a topic we can get into in
> more detail.
>
> - BW

Then there is no reason to use patches. Can you help me how to do it with
heightfield?

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"gulino" <nomail@nomail> wrote:

> Then there is no reason to use patches. Can you help me how to do it with
> heightfield?

https://wiki.povray.org/content/Reference:Height_Field

You can use either an image file or a pigment pattern to control the elevation,
or you can use a function if you have an equation that would give you the kind
of surface that you want.

f_hetero_mf(x,y,z, P0, P1, P2, P3, P4, P5): f_hetero_mf (x,0,z) makes
multifractal height fields and patterns of 1/f noise. Multifractal refers to
their characteristic of having a fractal dimension which varies with altitude.
Built from summing noise of a number of frequencies, the hetero_mf parameters
determine how many, and which frequencies are to be summed. An advantage to
using these instead of a height_field {} from an image (a number of height field
programs output multifractal types of images) is that the hetero_mf function
domain extends arbitrarily far in the x and z directions so huge landscapes can
be made without losing resolution or having to tile a height field. Other
functions of interest are f_ridged_mf and f_ridge.

P0 : H is the negative of the exponent of the basic noise frequencies used in
building these functions (each frequency f's amplitude is weighted by the factor
f - H ). In landscapes, and many natural forms, the amplitude of high frequency
contributions are usually less than the lower frequencies. When H is 1, the
fractalization is relatively smooth (1/f noise). As H nears 0, the high
frequencies contribute equally with low frequencies as in white noise.
P1 : Lacunarity is the multiplier used to get from one octave to the next. This
parameter affects the size of the frequency gaps in the pattern. Make this
greater than 1.0
P2 : Octaves is the number of different frequencies added to the fractal. Each
Octave frequency is the previous one multiplied by Lacunarity, so that using a
large number of octaves can get into very high frequencies very quickly.
P3 : Offset is the base altitude (sea level) used for the heterogeneous scaling
P4 : T scales the heterogeneity of the fractal. T=0 gives straight 1/f (no
heterogeneous scaling). T=1 suppresses higher frequencies at lower altitudes
P5 : Generator type used to generate the noise3d. 0, 1, 2 and 3 are legal
values.

https://wiki.povray.org/content/Reference:Functions.inc

https://news.povray.org/povray.general/thread/%3Cweb.63ea928499ce13121f9dae3025979125%40news.povray.org%3E/?ttop=444970
&toff=150&mtop=439826

See what you can to work with that, and then come back with any questions.
Also there are the files in the example directories supplied with your POV-Ray
distribution, and also the drop-down Insert Menu in the editor.
Probably under Special Shapes > Isosurfaces and Height_Fields, ....

- BW

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Le 2025-03-31 à 10:17, gulino a écrit :

> I want to make a plain like this image, I think heightfields will not work
> because it's for mountains. I am not sure how many patches but for sure more
> than one. It would be nice if there is a program that for example can make these
> and give me the value of the points because it seems very hard doing by hand
Heightfields can be used for mountains, but, that's just one of the many 
way they can be used.
What you show here can perfectly be done using a heightfield.

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