"Lars R." <rou### [at] gmxde> wrote:

> But with 10h render time per frame it is hopeless to do any animations
> with it. :'-(


I thought about this some more, and I wonder if you generate a mesh of the
fractal, if you can speed up the animation by using the saved mesh.

If you subtract away the half facing away from the camera, it ought to look the
same, and potentially speed up the render time as well.

You can use a difference, a contained_by box for your isosurface, or back-face
culling of the mesh.

Graphics Gems has some tips and tricks for speeding up code with pre-defined
values and look-up tables for things like sqrt() and trig functions.

I think if you take a look at
https://nylander.wordpress.com/2008/08/25/cross-section-of-the-quintic-calabi-yau-manifold/
http://bugman123.com/Physics/Calabi-Yau.zip
you'll see that he generates his surface by a parametric set of equations,
populates an array of vertices and normals, and then generates a "mesh" of
smooth_triangles.
I did some similar work with my parametric animations.
You might be able to turn those arrays into proper mesh{} objects and save them
to a file.

I'd say the only other option would be to use a 3rd party tool to generate the
fractal mesh quickly (non-SDL), and then use POV-ray to render it.

Maybe that's a bit more helpful.

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https://en.wikipedia.org/wiki/Mandelbulb

has some links that list software to generate 3D fractals like the Mandelbulb,
etc.
Perhaps you would find those useful.

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On 8/1/2017 6:02 PM, Bald Eagle wrote:
>
> https://en.wikipedia.org/wiki/Mandelbulb
>
> has some links that list software to generate 3D fractals like the Mandelbulb,
> etc.
> Perhaps you would find those useful.
>

I did, thanks.
I downloaded Mandelbulb 3D today but still need to find how to texture 
the mesh.


http://mandelbulb.com/2014/mandelbulb-3d-mb3d-fractal-rendering-software/

-- 

Regards
     Stephen

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Stephen <mca### [at] aolcom> wrote:

> I did, thanks.
> I downloaded Mandelbulb 3D today but still need to find how to texture
> the mesh.

Do you mean color-code the different areas of the mesh?

You'll probably need to define a pigment function that mirrors the shape.

So, for instance, Paul Nylander colors his Calabi-Yau "mesh" using:

pigment {
function {atan2(y-x,sqrt(2)*z)/(2*pi)}

color_map{
[0 rgbt <1,0,0,0.5>]
[1/6 rgbt <1,1,0,0.5>]
[1/3 rgbt <0,1,0,0.5>]
[1/2 rgbt <0,1,1,0.5>]
[2/3 rgbt <0,0,1,0.5>]
[5/6 rgbt <1,0,1,0.5>]
[1 rgbt <1,0,0,0.5>]}}

finish {reflection 0.4}
}

That produces the HSV-style hue gradient going around the 5-fold symmetry.

Perhaps you can search around for color functions that people have used and come
up with something along those lines.

Post a reply to this message

On 8/1/2017 8:04 PM, Bald Eagle wrote:
> Stephen <mca### [at] aolcom> wrote:
>
>> I did, thanks.
>> I downloaded Mandelbulb 3D today but still need to find how to texture
>> the mesh.
>
> Do you mean color-code the different areas of the mesh?
>
> You'll probably need to define a pigment function that mirrors the shape.
>

Yes, I guessed as much.

> So, for instance, Paul Nylander colors his Calabi-Yau "mesh" using:
>
> pigment {
> function {atan2(y-x,sqrt(2)*z)/(2*pi)}
>
> color_map{
> [0 rgbt <1,0,0,0.5>]
> [1/6 rgbt <1,1,0,0.5>]
> [1/3 rgbt <0,1,0,0.5>]
> [1/2 rgbt <0,1,1,0.5>]
> [2/3 rgbt <0,0,1,0.5>]
> [5/6 rgbt <1,0,1,0.5>]
> [1 rgbt <1,0,0,0.5>]}}
>
> finish {reflection 0.4}
> }
>
> That produces the HSV-style hue gradient going around the 5-fold symmetry.
>

Thanks I'll try that.

> Perhaps you can search around for color functions that people have used and come
> up with something along those lines.
>

I intend to but I've just found the s/ware and there is so much to do 
and only one life to do it in.


-- 

Regards
     Stephen

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