Ok, the last one with the ant...

-- 
Jaime Vives Piqueres

http://www.ignorancia.org

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Jaime Vives Piqueres <jai### [at] ignoranciaorg> wrote:
> Ok, the last one with the ant...

Oh wow - that is stunningly real! Amazing job!

I spent about 5 minutes looking at it to see if there was anything that gave it
away as a render, and the only thing I could come up with was the green sprouts
coming through the sand look a little plasticy - are you using 3.7 or Megapov?
If it's 3.7, I reckon some SSLT on those will complete the illusion completely.

Cheers,
Edouard.

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Jaime Vives Piqueres <jai### [at] ignoranciaorg> wrote:
> Ok, the last one with the ant...

I think the sand or dirt could use a bit more color variation among the
'grains', but those chaotic pebbles are quite amazing, *so* real. I tried
something similar in the past, but never even came close to what you've done.
Kudos!

Ken

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El 05/05/10 11:12, Edouard escribió:
> Oh wow - that is stunningly real! Amazing job!

   Thanks!

> I spent about 5 minutes looking at it to see if there was anything that
> gave it away as a render, and the only thing I could come up with was the
> green sprouts coming through the sand look a little plasticy - are you
> using 3.7 or Megapov? If it's 3.7, I reckon some SSLT on those will
> complete the illusion completely.

   I'm using the beta for this one, so here it is with SSLT on the sprouts.
I've just plagiarized the demo scene, changing the colors and the mm per
unit until it looked (somewhat) right. But this, and 7 more samples on the
focal blur, increased the render time from 6 to 11 hours...

   BTW, this scene renders much faster than expected with the beta, judging
by the speed of both 3.6 and MegaPOV with it. Almost 6 times faster! ...but
before trying it with the beta, I was already puzzled by how slow it was
with MegaPOV and 3.6, so perhaps it was just a bug that got fixed.


-- 
Jaime Vives Piqueres

http://www.ignorancia.org

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El 05/05/10 14:07, Kenneth escribió:
> I think the sand or dirt could use a bit more color variation among the
> 'grains'

   It *HAS* a very wide variation in grain colors, but the focal blur makes
it almost disappear... and if I make the grain bigger to avoid this, it
doesn't look like grains anymore. :(

> but those chaotic pebbles are quite amazing, *so* real. I tried something
> similar in the past, but never even came close to what you've done.

   Me too, tried it before but never got it right... I think it's due to the
fact that I was always using a single while loop to place the pebbles, but
this time used 3 loops, with increasing random sizes and decreasing number
of pebbles. Also, the pebbles are not totally random in their placement, as
I used a pigment function (granite) to determine if a pebble should be
placed or not. And BTW, it is just a single mesh pebble made with
Wings3d... :)


-- 
Jaime Vives Piqueres

http://www.ignorancia.org

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Am 06.05.2010 11:27, schrieb Jaime Vives Piqueres:
> El 05/05/10 14:07, Kenneth escribió:
>> I think the sand or dirt could use a bit more color variation among the
>> 'grains'
>
> It *HAS* a very wide variation in grain colors, but the focal blur makes
> it almost disappear... and if I make the grain bigger to avoid this, it
> doesn't look like grains anymore. :(

See <http://www.tc-rtc.co.uk/imagenewdisplay/stills/index207.html> for 
some other approach at sand.

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El 06/05/10 11:30, clipka escribió:
> Am 06.05.2010 11:27, schrieb Jaime Vives Piqueres:
>> El 05/05/10 14:07, Kenneth escribió:
>>> I think the sand or dirt could use a bit more color variation among
>>> the 'grains'
>>
>> It *HAS* a very wide variation in grain colors, but the focal blur
>> makes it almost disappear... and if I make the grain bigger to avoid
>> this, it doesn't look like grains anymore. :(
>
> See <http://www.tc-rtc.co.uk/imagenewdisplay/stills/index207.html> for
> some other approach at sand.

   Ah, yes... that's the best POV-Ray sand to date! In fact, I did remember
about it at first, when I was using MegaPOV, but it was extremely slow to
render with 100,000 spheres. And later I forgot to try it again with the
beta... well, that will be the first job for the AMD Phenom II X4 that I
just purchased. :)


-- 
Jaime Vives Piqueres

http://www.ignorancia.org

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Very cool. I like the degree of realism here.

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Jaime Vives Piqueres <jai### [at] ignoranciaorg> wrote:
> Also, the pebbles are not totally random in their placement, as
> I used a pigment function (granite) to determine if a pebble should be
> placed or not.

Very clever!  It seems to eliminate the 'clumping together' that usually occurs
when using a 'random' distribution. Using eval_pigment, I suppose? Must remember
this trick!

Ken

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"Jaime Vives Piqueres" <jai### [at] ignoranciaorg> schreef in bericht 
news:4be28a6f@news.povray.org...
>   Me too, tried it before but never got it right... I think it's due to 
> the
> fact that I was always using a single while loop to place the pebbles, but
> this time used 3 loops, with increasing random sizes and decreasing number
> of pebbles. Also, the pebbles are not totally random in their placement, 
> as
> I used a pigment function (granite) to determine if a pebble should be
> placed or not. And BTW, it is just a single mesh pebble made with
> Wings3d... :)

Additionally, what you can use to good effect, is the prob() function.

Excellent image (as always).... I am finishing a desert scene which I shall 
show here soon. Much cruder textures however than your finely realistic ones 
:-(

Thomas

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Jaime Vives Piqueres <jai### [at] ignoranciaorg> wrote:
>    Me too, tried it before but never got it right... I think it's due to the
> fact that I was always using a single while loop to place the pebbles, but
> this time used 3 loops, with increasing random sizes and decreasing number
> of pebbles. Also, the pebbles are not totally random in their placement, as
> I used a pigment function (granite) to determine if a pebble should be
> placed or not. And BTW, it is just a single mesh pebble made with
> Wings3d... :)

randomized proceduralized placement, randomized proceduralized mesh-based
geometry, randomized proceduralized imagemap-based texturing (not necessarily in
this one)... you're such a random procedural magician! :D

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On 05/06/2010 11:30 AM, clipka wrote:
> See <http://www.tc-rtc.co.uk/imagenewdisplay/stills/index207.html> for
> some other approach at sand.

   Ok, after a painful move to the new AMD Phenom II x4, that took two days
to complete, finally got the chance to try it out. I added 350,000 spheres
and it still rendered in 4h! :)


-- 
Jaime Vives Piqueres

http://www.ignorancia.org

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"Jaime Vives Piqueres" <jai### [at] ignoranciaorg> schreef in bericht 
news:4be6d7d4@news.povray.org...
>   Ok, after a painful move to the new AMD Phenom II x4, that took two days
> to complete, finally got the chance to try it out. I added 350,000 spheres
> and it still rendered in 4h! :)
>

Yes! This is the real world! :-)

Thomas

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"Jaime Vives Piqueres" <jai### [at] ignoranciaorg> schreef in bericht 
news:4be6d7d4@news.povray.org...
>   Ok, after a painful move to the new AMD Phenom II x4, that took two days
> to complete, finally got the chance to try it out. I added 350,000 spheres
> and it still rendered in 4h! :)

Just thinking: With the DoF, you may get away with a lesser number of 
spheres, or are they all concentrated in the sharp zone?

Thomas

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On 05/06/2010 01:59 PM, Kenneth wrote:
> Very clever!  It seems to eliminate the 'clumping together' that usually
> occurs when using a 'random' distribution. Using eval_pigment, I suppose?
> Must remember this trick!

   No, just using the pigment function on a #if statement against the stone
location:

   #if (f_distrib(stone_location.x,0,stone_location.z).gray<=.5)

   where stone_location was generated randomly over the height_field.

-- 
Jaime Vives Piqueres

http://www.ignorancia.org

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On 05/06/2010 03:49 PM, Thomas de Groot wrote:
> Additionally, what you can use to good effect, is the prob() function.

   prob()??? ...I've never heard of that function. In fact, the only thing I
can find is prod(), which was also unknown to me, and can't see how would
use it here.

> Excellent image (as always).... I am finishing a desert scene which I
> shall show here soon. Much cruder textures however than your finely
> realistic ones

   I cheated greatly there... ;) there is only one texture for the stones,
which is a "procedularized" picture of a pebbles bed. I scaled it really
big, and translated it randomly for each pebble, making the finish also
random for each one.

-- 
Jaime Vives Piqueres

http://www.ignorancia.org

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On 05/06/2010 05:29 PM, nemesis wrote:
> randomized proceduralized placement, randomized proceduralized mesh-based
> geometry, randomized proceduralized imagemap-based texturing (not
> necessarily in this one)... you're such a random procedural magician! :D
>

   I love rand()!!! I use it even for things as bizarre as finding the camera
placement! ;)

-- 
Jaime Vives Piqueres

http://www.ignorancia.org

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On 05/10/2010 09:26 AM, Thomas de Groot wrote:
> Just thinking: With the DoF, you may get away with a lesser number of
> spheres, or are they all concentrated in the sharp zone?

   No, I'm not that sharp: they are scattered evenly. And there is a real
difference in realism even on the blurred zones. Oh, and 3.7 managed to
parse all the scene in 29 seconds, so why bother? :)

-- 
Jaime Vives Piqueres

http://www.ignorancia.org

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Am 09.05.2010 17:41, schrieb Jaime Vives Piqueres:
> On 05/06/2010 11:30 AM, clipka wrote:
>> See <http://www.tc-rtc.co.uk/imagenewdisplay/stills/index207.html> for
>> some other approach at sand.
>
> Ok, after a painful move to the new AMD Phenom II x4, that took two days
> to complete, finally got the chance to try it out. I added 350,000 spheres
> and it still rendered in 4h! :)

Looking /really/ good now!

Yes, a neat QuadCore is fun with POV-Ray ;-)

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"Jaime Vives Piqueres" <jai### [at] ignoranciaorg> schreef in bericht 
news:4be7c030@news.povray.org...
> On 05/06/2010 03:49 PM, Thomas de Groot wrote:
>> Additionally, what you can use to good effect, is the prob() function.
>
>   prob()??? ...I've never heard of that function. In fact, the only thing 
> I
> can find is prod(), which was also unknown to me, and can't see how would
> use it here.

It is not described in the docs it seems... You can find the probability 
macro as the first one in rand.inc. I use it quite often to select between 
different plants for instance, or any selection of objects.

>
>> Excellent image (as always).... I am finishing a desert scene which I
>> shall show here soon. Much cruder textures however than your finely
>> realistic ones
>
>   I cheated greatly there... ;) there is only one texture for the stones,
> which is a "procedularized" picture of a pebbles bed. I scaled it really
> big, and translated it randomly for each pebble, making the finish also
> random for each one.

Great technique! I shall remember that.

Thomas

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On 05/10/2010 11:33 AM, Thomas de Groot wrote:
> It is not described in the docs it seems... You can find the probability 
> macro as the first one in rand.inc. I use it quite often to select between 
> different plants for instance, or any selection of objects.

ha ... new one on me as well! since you've used it, perhaps you could
come up with a sentence or two and i'll add it to the wiki docs

i'll watch this thread or you can put it over here:
http://wiki.povray.org/content/Documentation_Talk:Reference_Section_7.3

jim

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"Jim Holsenback" <jho### [at] povrayorg> schreef in bericht 
news:4be82250$1@news.povray.org...
> ha ... new one on me as well! since you've used it, perhaps you could
> come up with a sentence or two and i'll add it to the wiki docs
>
> i'll watch this thread or you can put it over here:
> http://wiki.povray.org/content/Documentation_Talk:Reference_Section_7.3
>

Well, you could maybe use something like this:

Prob(P, RS)
The probability macro returns true or false. P is the probability of 
returning true (value between 0 and 1) RS is a random number stream.
Example code:
//start code
//If you want a 40% chance of red objects amongst blue ones
#local ObjProb = Prob(0.4, r);
object {
  #if (ObjProb)
    RedObj
  #else
    BlueObj
  #end
  .....
}
//end code


Thomas

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On 05/11/2010 05:28 AM, Thomas de Groot wrote:
> Well, you could maybe use something like this:

haha ... I think WE ALL deserve a RTFM on this one ;-)

It was already there:
http://wiki.povray.org/content/Documentation:Reference_Section_7.3#Discrete_Distributions

In the unix docs it's in section:
3.7.11.2.3 Discrete Distributions

Jim

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"Jim Holsenback" <jho### [at] povrayorg> schreef in bericht 
news:4be91fcd$1@news.povray.org...
>
> haha ... I think WE ALL deserve a RTFM on this one ;-)
>
> It was already there:
>
http://wiki.povray.org/content/Documentation:Reference_Section_7.3#Discrete_Distributions
>
> In the unix docs it's in section:
> 3.7.11.2.3 Discrete Distributions
>

The thing is that in the unix docs, it does not appear in the Index....  so, 
I assumed...


Thomas

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On 05/11/2010 11:39 AM, Thomas de Groot wrote:
> it does not appear in the Index....

it was missing this tag needed for it to appear in the index listing:
<!--<indexentry primary "Prob">--->

Jim

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