"Trevor G Quayle" <Tin### [at] hotmailcom> wrote:
>
> Since you want to basaltic columns, if you want to randomize them a bit more,
> you probably still want a general six-sidded shape.

Well from looking at images some are less but I think that would just over
complicate things so six sides are fine ;-)

>
> One way you can do this is:
> 1. Generate a hexagonal array of points at the average offset/size you want
> 2. Apply a random small x and y offset to each
> 3. creat prisms based on a voronoi tesselation of the points
> - for each point, find the distance and direction to each of its 6 neighbours
> - for each of these pairs, create a plane at the exact midpoint, and
> perpendicular to the direction vector
> - you will have 6 vertical planes for each point, create a CSG intersection of
> the 6 planes (plus a top height plane).
> - this should result in having a six sided array with no gaps, bu the hexagons
> won't be perfect hexagons

Hmm, not sure if my math skills are up to this, I am sure it is not that
complicated but I never paid enough attention in this subject, if only they had
used POV back then to make it more interesting..

>
> The next difficult step is determining hor to make rounded or chamfered edges to
> these shapes if you want.

The current columns are made from intersecting 7 height fields (one for the top)
so similar to what you are referring to above with planes but with the obvious
advantages. I am rounding/beveling the edges by combining the granite/wrinkles
pigments with a gradient pattern to raise the edges of the hieght fields then
sizing them appropriately so the raised edges meet up. The top one has a granite
and sperical pattern to get the raised or sunk look for the puddles.

I will have to have a go at this but fear it may take me the 70 odd days to the
deadline to work it out ;-)

Thanks

Sean

Post a reply to this message

On Wed, 05 Jun 2013 21:59:23 +0200, s.day <s.d### [at] uelacuk> wrote:

> "Trevor G Quayle" <Tin### [at] hotmailcom> wrote:
>>
>> Since you want to basaltic columns, if you want to randomize them a bit  
>> more,
>> you probably still want a general six-sidded shape.
>
> Well from looking at images some are less but I think that would just  
> over
> complicate things so six sides are fine ;-)
>
>>
>> One way you can do this is:
>> 1. Generate a hexagonal array of points at the average offset/size you  
>> want
>> 2. Apply a random small x and y offset to each
>> 3. creat prisms based on a voronoi tesselation of the points
>> - for each point, find the distance and direction to each of its 6  
>> neighbours
>> - for each of these pairs, create a plane at the exact midpoint, and
>> perpendicular to the direction vector
>> - you will have 6 vertical planes for each point, create a CSG  
>> intersection of
>> the 6 planes (plus a top height plane).
>> - this should result in having a six sided array with no gaps, bu the  
>> hexagons
>> won't be perfect hexagons
>
> Hmm, not sure if my math skills are up to this, I am sure it is not that
> complicated but I never paid enough attention in this subject, if only  
> they had
> used POV back then to make it more interesting..
>
>>
>> The next difficult step is determining hor to make rounded or chamfered  
>> edges to
>> these shapes if you want.
>
> The current columns are made from intersecting 7 height fields (one for  
> the top)
> so similar to what you are referring to above with planes but with the  
> obvious
> advantages. I am rounding/beveling the edges by combining the  
> granite/wrinkles
> pigments with a gradient pattern to raise the edges of the hieght fields  
> then
> sizing them appropriately so the raised edges meet up. The top one has a  
> granite
> and sperical pattern to get the raised or sunk look for the puddles.
>
> I will have to have a go at this but fear it may take me the 70 odd days  
> to the
> deadline to work it out ;-)
>

Try adding a small random component to the rotation of each plane.
For instance if you have the following:

plane{z, 0 rotate y*60}

first declare a seed
#declare RandSeed=97531;

change your plane as follows
plane{z, 0 rotate y*(60+5*rand(RandSeed))



-- 
-Nekar Xenos-

Post a reply to this message

"Trevor G Quayle" <Tin### [at] hotmailcom> wrote:
> One way you can do this is:
> 1. Generate a hexagonal array of points at the average offset/size you want
> 2. Apply a random small x and y offset to each
> 3. creat prisms based on a voronoi tesselation of the points
> - for each point, find the distance and direction to each of its 6 neighbours
> - for each of these pairs, create a plane at the exact midpoint, and
> perpendicular to the direction vector
> - you will have 6 vertical planes for each point, create a CSG intersection of
> the 6 planes (plus a top height plane).
> - this should result in having a six sided array with no gaps, bu the hexagons
> won't be perfect hexagons
>

Don't think I am fully using the technique mentioned above but it got me far
enough to randomise the shapes as in the attached. Also took the hint from
Thomas to change the edges of causeway to make it less even.

I did not add the clouds/sun/fog etc in this image it was just to check the
shape of the causeway and columns. Still more work to do but I am much happier
with this part of the scene.

Thanks

Sean

Post a reply to this message

Attachments:
Download 'giants_new_shape.jpg' (640 KB)

Preview of image 'giants_new_shape.jpg'

On 9-6-2013 15:58, s.day wrote:
> Don't think I am fully using the technique mentioned above but it got me far
> enough to randomise the shapes as in the attached. Also took the hint from
> Thomas to change the edges of causeway to make it less even.
>

Oooh! Looking awfully good!

Thomas

Post a reply to this message

>s.day  on date 09/06/2013 15.58 wrote:

> I did not add the clouds/sun/fog etc in this image it was just to check the
> shape of the causeway and columns. Still more work to do but I am much happier
> with this part of the scene.

I really like it,
   Paolo

Post a reply to this message

I love your picture, realistic textures and greatly done, god job !

Post a reply to this message

On 16/06/2013 5:50 PM, Lightbeam wrote:
> I love your picture, realistic textures and greatly done, god job !

LOL

God job! :-D

-- 
Regards
     Stephen

Post a reply to this message

Lightbeam wrote:
> I love your picture, realistic textures and greatly done, god job !

Thanks, I am still working on this one just trying to get a decent 
looking sky, this is turning out to be one of my weaker skills though..

Sean

Post a reply to this message

On Mon, 17 Jun 2013 01:33:06 +0200, Sean Day <s.d### [at] uelacuk> wrote:

> Lightbeam wrote:
>> I love your picture, realistic textures and greatly done, god job !
>
> Thanks, I am still working on this one just trying to get a decent  
> looking sky, this is turning out to be one of my weaker skills though..
>
> Sean

mediasky.pov in scenes/advanced could be a good start.
-- 
-Nekar Xenos-

Post a reply to this message

"Nekar Xenos" <nek### [at] gmailcom> wrote:
> On Mon, 17 Jun 2013 01:33:06 +0200, Sean Day <s.d### [at] uelacuk> wrote:
>
> mediasky.pov in scenes/advanced could be a good start.
> --
> -Nekar Xenos-

Thanks for the hint, that is an intersting scene. I have managed to get a sky I
like from running lots of fairly slow test renders, the problem now is that when
I add it to my scene and try to render with focal blur/radiosity etc it is so
slow. Think I will have to be very patient with this one.. At least there is
still plenty of time to the competition deadline.


Sean

Post a reply to this message