Thanks to Dan P's post I was able to create in POV Ray 3.1 
a brushed metal that looked very similar to the "before" picture, which I
was entirely happy with. But I have since upgraded to POV Ray 3.5 and the
EXACT same settings produce the horrible mess in the "after" picture. My
normal settings are:

normal {
   granite
   0.1
   scale <0.1, 20, 1>
}

I've tried changing changing the depth, scale, rotation, bump depth,
accuracy, noise generator, and turbulence but I can't achieve the same
effect in 3.5, what am I doing wrong?

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Attachments:
Download '?.jpg' (60 KB)

Preview of image '?.jpg'

> I've tried changing changing the depth, scale, rotation, bump depth,
> accuracy, noise generator, and turbulence but I can't achieve the same
> effect in 3.5, what am I doing wrong?

First of all, it doesn't look like the two scenes are the same, lighting,
angle, everythings seems slightly different. Have you tried "no_bump_scale"
yet?

Regards,
Tim

-- 
"Tim Nikias v2.0"
Homepage: <http://www.nolights.de>

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Program ended abnormally on 26/04/2004 18:05, Due to a catastrophic Dustin error:
>         Thanks to Dan P's post I was able to create in POV Ray 3.1 
> a brushed metal that looked very similar to the "before" picture, which I
> was entirely happy with. But I have since upgraded to POV Ray 3.5 and the
> EXACT same settings produce the horrible mess in the "after" picture. My
> normal settings are:
> 
> normal {
>    granite
>    0.1
>    scale <0.1, 20, 1>
> }
> 
> I've tried changing changing the depth, scale, rotation, bump depth,
> accuracy, noise generator, and turbulence but I can't achieve the same
> effect in 3.5, what am I doing wrong?
> 

There were changes in the noise generating routines in POV 3.5, try adding:

global_settings{
   noise_generator 1
}

To your scene to see if it helps.

-- 
/*Francois Labreque*/#local a=x+y;#local b=x+a;#local c=a+b;#macro P(F//
/*    flabreque    */L)polygon{5,F,F+z,L+z,L,F pigment{rgb 9}}#end union
/*        @        */{P(0,a)P(a,b)P(b,c)P(2*a,2*b)P(2*b,b+c)P(b+c,<2,3>)
/*   videotron.ca  */}camera{orthographic location<6,1.25,-6>look_at a }

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Dustin wrote:

>         Thanks to Dan P's post I was able to create in POV Ray 3.1 
> a brushed metal that looked very similar to the "before" picture, which I
> was entirely happy with. But I have since upgraded to POV Ray 3.5 and the
> EXACT same settings produce the horrible mess in the "after" picture. My
> normal settings are:
> 
> normal {
>    granite
>    0.1
>    scale <0.1, 20, 1>
> }
> 
> I've tried changing changing the depth, scale, rotation, bump depth,
> accuracy, noise generator, and turbulence but I can't achieve the same
> effect in 3.5, what am I doing wrong?

Looks like the light source is /in/ the object somehow...?
-- 
Respectfully,
Dan P
http://<broken link>

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Tim Nikias v2.0 wrote:

> 
> First of all, it doesn't look like the two scenes are the same, lighting,
> angle, everythings seems slightly different. Have you tried
> "no_bump_scale" yet?
> 
> Regards,
> Tim
> 

They aren't the same, I didn't render the "before" scene, that is from
Dan P's post. I'll post is actual sample from 3.1 and 3.5 (same
settings). 
I tried "no_bump_scale" it does not seem to make any difference :(

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Attachments:
Download 'difference.jpg' (146 KB)

Preview of image 'difference.jpg'

> There were changes in the noise generating routines in POV 3.5, try
> adding:
> 
> global_settings{
>    noise_generator 1
> }
> 
> To your scene to see if it helps.
> 

Thanks, I tried that, it didn't make a difference.

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Dustin wrote:

> Tim Nikias v2.0 wrote:
> 
>>First of all, it doesn't look like the two scenes are the same, lighting,
>>angle, everythings seems slightly different. Have you tried
>>"no_bump_scale" yet?
>>
>>Regards,
>>Tim
>>
> 
> They aren't the same, I didn't render the "before" scene, that is from
> Dan P's post. I'll post is actual sample from 3.1 and 3.5 (same
> settings). 
> I tried "no_bump_scale" it does not seem to make any difference :(

DAMN, that is a cool lookin' leg!
-- 
Respectfully,
Dan P
http://<broken link>

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> DAMN, that is a cool lookin' leg!

Thanks, I *WAS* happy with how things were turning out until I decided to
upgrade in the middle of the model. Could you post the code to your
'brushed metal scene' example? Maybe I can compare and find out where I am
going wrong...

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Interesting problem. I've just tried it out comparing 3.5 to Megapov 0.7 (based
on pov 3.1) and I think I have the solution, try this:

 normal {
  pigment_pattern {
   granite
   scale <0.1, 20, 1>
  } 0.1
 }

I've noticed that pov seems to generate bumps by comparing samples of the bump
pattern to estimate a gradient (by sampling a fixed distance away). It would
appear 3.1 evaluates this sample distance after the pattern has been scaled,
whereas 3.5 does it before the scaling. This means if you scale a pattern in 3.5
the bumps will appear to scale, whereas in 3.1 they will alter as they scale
(becoming smoother as you scale down).

In any case using pigment_pattern allows you to manipulate the pattern before
pov samples a normal from it. One trick I use is: normal { pigment_pattern {
granite scale f } 1 scale 1/f }, so that by varying the value of f you control
the severity of the bumps.

Hope that helps
-- 
Tek
www.evilsuperbrain.com

"Dustin" <xkx### [at] excitecom> wrote in message news:408da502@news.povray.org...
>         Thanks to Dan P's post I was able to create in POV Ray 3.1
> a brushed metal that looked very similar to the "before" picture, which I
> was entirely happy with. But I have since upgraded to POV Ray 3.5 and the
> EXACT same settings produce the horrible mess in the "after" picture. My
> normal settings are:
>
> normal {
>    granite
>    0.1
>    scale <0.1, 20, 1>
> }
>
> I've tried changing changing the depth, scale, rotation, bump depth,
> accuracy, noise generator, and turbulence but I can't achieve the same
> effect in 3.5, what am I doing wrong?
>
>

Post a reply to this message

Tek wrote:

> Interesting problem. I've just tried it out comparing 3.5 to Megapov 0.7
> (based on pov 3.1) and I think I have the solution, try this:
> 
>  normal {
>   pigment_pattern {
>    granite
>    scale <0.1, 20, 1>
>   } 0.1
>  }
> 
> I've noticed that pov seems to generate bumps by comparing samples of the
> bump pattern to estimate a gradient (by sampling a fixed distance away).
> It would appear 3.1 evaluates this sample distance after the pattern has
> been scaled, whereas 3.5 does it before the scaling. This means if you
> scale a pattern in 3.5 the bumps will appear to scale, whereas in 3.1 they
> will alter as they scale (becoming smoother as you scale down).
> 
> In any case using pigment_pattern allows you to manipulate the pattern
> before pov samples a normal from it. One trick I use is: normal {
> pigment_pattern { granite scale f } 1 scale 1/f }, so that by varying the
> value of f you control the severity of the bumps.
> 
> Hope that helps

Thanks alot, I think this may work, I am trying to set it up now...

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