Well, I've finally done it. I managed to get my first tutorial up at my
website.
It describes how to create a planet's atmosphere using media. You can access
it in the tutorial section of my website (see address below). Please let me
know what you think of it. Hopefully, I will be able to offer new tutorials
in the future.

Cheers,
Darcy
djo### [at] inamecomNOSPAM
http://www.geocities.com/SiliconValley/Sector/4317

Post a reply to this message

"Darcy Johnston" <djo### [at] inamecomNOSPAM> wrote:
> Well, I've finally done it. I managed to get my first tutorial up at my
> website.
> It describes how to create a planet's atmosphere using media. You can access
> it in the tutorial section of my website (see address below). Please let me
> know what you think of it. Hopefully, I will be able to offer new tutorials
> in the future.
>
> Cheers,
> Darcy
> djo### [at] inamecomNOSPAM
> http://www.geocities.com/SiliconValley/Sector/4317

Dammit Geocities!!!!!!


Mike

Post a reply to this message

"posfan12" <nomail@nomail> wrote:
> "Darcy Johnston" <djo### [at] inamecomNOSPAM> wrote:
> > Well, I've finally done it. I managed to get my first tutorial up at my
> > website.
> > It describes how to create a planet's atmosphere using media. You can access
> > it in the tutorial section of my website (see address below). Please let me
> > know what you think of it. Hopefully, I will be able to offer new tutorials
> > in the future.
> >
> > Cheers,
> > Darcy
> > djo### [at] inamecomNOSPAM
> > http://www.geocities.com/SiliconValley/Sector/4317
>
> Dammit Geocities!!!!!!
>
>
> Mike

Hi Mike,

a lot of Geocities can be found at the wayback machine (web.archive.org):

http://web.archive.org/web/19990202172115/http://www.geocities.com/SiliconValley/Sector/4317/

Best regards,
Michael

Post a reply to this message

"MichaelJF" <mi-### [at] t-onlinede> wrote:
> Hi Mike,
>
> a lot of Geocities can be found at the wayback machine (web.archive.org):
>
>
http://web.archive.org/web/19990202172115/http://www.geocities.com/SiliconValley/Sector/4317/
>
> Best regards,
> Michael

Thank you!


Mike

Post a reply to this message

This tutorial assumes the planet radius is always 1. What do I need to 
do if the radius is some other value? thanks.


Mike



On 10/13/2013 3:40 AM, posfan12 wrote:
> "MichaelJF" <mi-### [at] t-onlinede> wrote:
>> Hi Mike,
>>
>> a lot of Geocities can be found at the wayback machine (web.archive.org):
>>
>>
http://web.archive.org/web/19990202172115/http://www.geocities.com/SiliconValley/Sector/4317/
>>
>> Best regards,
>> Michael
> 
> Thank you!
> 
> 
> Mike
>

Post a reply to this message

Op 10/01/2021 om 05:13 schreef Mike Horvath:
> This tutorial assumes the planet radius is always 1. What do I need to 
> do if the radius is some other value? thanks.
> 
> 
> Mike
> 

The quick answer would be:
1) define a new radius for the planet; e.g. Radius = 100;
2)  multiply the rgb value in the media elements (scattering in the 
example) by 1/Radius; e.g. scattering {4, rgb <.4,.5,1>*5*(1/Radius) 
extinction .00005}
3) Scale your planet and atmosphere union; e.g. union{ sphere{...} 
sphere{...} scale 100}

-- 
Thomas

Post a reply to this message

Op 10/01/2021 om 08:41 schreef Thomas de Groot:
> Op 10/01/2021 om 05:13 schreef Mike Horvath:
>> This tutorial assumes the planet radius is always 1. What do I need to 
>> do if the radius is some other value? thanks.
>>
>>
>> Mike
>>
> 
> The quick answer would be:
> 1) define a new radius for the planet; e.g. Radius = 100;

> example) by 1/Radius; e.g. scattering {4, rgb <.4,.5,1>*5*(1/Radius) 
> extinction .00005}
> 3) Scale your planet and atmosphere union; e.g. union{ sphere{...} 
> sphere{...} scale 100}
> 

I just see that the author additionally scales the atmosphere by 1.04. I 
think you should also compensate for that.

Another possibility would be to fix the planet's and atmosphere's radius 
from the start and not be troubled by extra scaling:

union{
    sphere {0, 100 texture {Planet1}}
    sphere {0, 104 hollow pigment{rgbt 1.0} interior {media {atmos1} 
media{atmos2}}}
}

The example above about scattering applies also to the absortion media 
of course.

-- 
Thomas

Post a reply to this message

Op 10/01/2021 om 08:49 schreef Thomas de Groot:
> Op 10/01/2021 om 08:41 schreef Thomas de Groot:
>> Op 10/01/2021 om 05:13 schreef Mike Horvath:
>>> This tutorial assumes the planet radius is always 1. What do I need 
>>> to do if the radius is some other value? thanks.
>>>
>>>
>>> Mike
>>>
>>
>> The quick answer would be:
>> 1) define a new radius for the planet; e.g. Radius = 100;

>> example) by 1/Radius; e.g. scattering {4, rgb <.4,.5,1>*5*(1/Radius) 
>> extinction .00005}
>> 3) Scale your planet and atmosphere union; e.g. union{ sphere{...} 
>> sphere{...} scale 100}
>>
> 
> I just see that the author additionally scales the atmosphere by 1.04. I 
> think you should also compensate for that.
> 
> Another possibility would be to fix the planet's and atmosphere's radius 
> from the start and not be troubled by extra scaling:
> 
> union{


> media{atmos2}}}
> }
> 
> The example above about scattering applies also to the absortion media 
> of course.
> 

And finally, just to be faster than Alain :-)
*Always* use intervals 1 and samples with only one value. Remember that 
this is a 1999 tutorial!

And now I shut up.


-- 
Thomas

Post a reply to this message