Hi,

Sometimes I want meshes too look a little more rough and get rid of some banding
artifacts. So I used to put "crand" in my finish statements in this case. But if
I use crand in Version 3.7 it has no effect anymore. Maybe it does not work in
3.7 because it was considered obsolete and taken out?

I've already tried small normals with bumps to get a similar effect as with
crand, but somehow it didn't look good, because they were distorted on some
parts of the mesh and not visible in very dark and light areas.

Can anyone tell me what I could use instead of crand in Version 3.7?

Best wishes

Simone

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On 05/19/2012 06:43 PM, mone wrote:
> Hi,
>
> Sometimes I want meshes too look a little more rough and get rid of some banding
> artifacts. So I used to put "crand" in my finish statements in this case. But if
> I use crand in Version 3.7 it has no effect anymore. Maybe it does not work in
> 3.7 because it was considered obsolete and taken out?
>
> I've already tried small normals with bumps to get a similar effect as with
> crand, but somehow it didn't look good, because they were distorted on some
> parts of the mesh and not visible in very dark and light areas.
>
> Can anyone tell me what I could use instead of crand in Version 3.7?
>
> Best wishes
>
> Simone
>
>
try the granite pattern, something scaled small (1e-2 or maybe 3) ... 
play around with it!
http://wiki.povray.org/content/Reference:Granite_Pattern

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James Holsenback <nom### [at] nonecom> wrote:
> >
> try the granite pattern, something scaled small (1e-2 or maybe 3) ...
> play around with it!
> http://wiki.povray.org/content/Reference:Granite_Pattern

Thank you for the tip James!
I tried different scales so far, it's a little difficult, 1e-8 is still too
strong, 1e-9 gives strange results with the lighting and with 1e-10 the pattern
is not visible. Maybe I will try it with a layered texture next ...

Best wishes

Simone

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> I tried different scales so far, it's a little difficult, 1e-8 is 
still too
 > strong, 1e-9 gives strange results with the lighting and with 1e-10 
the pattern
 > is not visible.

The scale of the normal won't affect its strength. Put a number 
immediately after the "granite" keyword to scale down its strength:

normal
{
     granite 0.1
     // ... scale, etc ...
}

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Slime <pov### [at] slimelandcom> wrote:
> > I tried different scales so far, it's a little difficult, 1e-8 is
> still too
>  > strong, 1e-9 gives strange results with the lighting and with 1e-10
> the pattern
>  > is not visible.
>
> The scale of the normal won't affect its strength. Put a number
> immediately after the "granite" keyword to scale down its strength:
>
> normal
> {
>      granite 0.1
>      // ... scale, etc ...
> }

Yes, thanks you. But it wasn't good with a normal because the normal pattern
doesn't show up in dark areas.
So I put it in pigment pattern instead, which did not work either.

But finally I used POV 3.6 again with "crand". (I thought I could get used to
POV 3.7 but it seems to be too different from older versions for my purposes.)

Best wishes

Simone

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Am 20.05.2012 00:43, schrieb mone:

> Sometimes I want meshes too look a little more rough and get rid of some banding
> artifacts. So I used to put "crand" in my finish statements in this case. But if
> I use crand in Version 3.7 it has no effect anymore. Maybe it does not work in
> 3.7 because it was considered obsolete and taken out?

What exactly do you mean with "banding artifacts"? Some mesh-specific 
stuff, or the banding that can occur when you have "slow" color 
transitions in the image (such as the sky)?

For the latter, 3.7's "Dither=on" or "+th" works like a charm.

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On 05/27/2012 10:48 PM, mone wrote:
> Slime<pov### [at] slimelandcom>  wrote:
>>> I tried different scales so far, it's a little difficult, 1e-8 is
>> still too
>>   >  strong, 1e-9 gives strange results with the lighting and with 1e-10
>> the pattern
>>   >  is not visible.
>>
>> The scale of the normal won't affect its strength. Put a number
>> immediately after the "granite" keyword to scale down its strength:
>>
>> normal
>> {
>>       granite 0.1
>>       // ... scale, etc ...
>> }
>
> Yes, thanks you. But it wasn't good with a normal because the normal pattern
> doesn't show up in dark areas.
> So I put it in pigment pattern instead, which did not work either.

maybe then a normal isn't /really/ the answer ... what about an 
isosurface sphere with noise?

http://wiki.povray.org/content/Documentation:Tutorial_Section_3.2#Noise_and_pigment_functions

towards the bottom of the above tutorial section are a couple examples

> But finally I used POV 3.6 again with "crand". (I thought I could get used to
> POV 3.7 but it seems to be too different from older versions for my purposes.)

don't give up ... 3.7 is WAY better in many aspects. I think if you try 
to push through the initial learning curve the rewards will become apparent

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On 28-5-2012 4:48, mone wrote:
> Yes, thanks you. But it wasn't good with a normal because the normal pattern
> doesn't show up in dark areas.

That's normal... :-)

> So I put it in pigment pattern instead, which did not work either.
>
> But finally I used POV 3.6 again with "crand". (I thought I could get used to
> POV 3.7 but it seems to be too different from older versions for my purposes.)
>

Maybe you should show us an example of what you try to achieve. Our 
answers would be better focussed I think.

Thomas

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James Holsenback <nom### [at] nonecom> wrote:
> try the granite pattern

  Note that the granite pattern is quite significantly slower to render
than using crand (well, in pov3.6 anyways, where crand is supported).

  If you want a slightly faster alternative, use the 'bumps' pattern
(scaled vary small).

-- 
                                                          - Warp

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On 20.05.12 00:43, mone wrote:
> Hi,
>
> Sometimes I want meshes too look a little more rough and get rid of some banding
> artifacts. So I used to put "crand" in my finish statements in this case. But if
> I use crand in Version 3.7 it has no effect anymore. Maybe it does not work in
> 3.7 because it was considered obsolete and taken out?
>
> I've already tried small normals with bumps to get a similar effect as with
> crand, but somehow it didn't look good, because they were distorted on some
> parts of the mesh and not visible in very dark and light areas.
>
> Can anyone tell me what I could use instead of crand in Version 3.7?

Actually, that crand is still disabled is a bug. I had disabled it early on 
during 3.7 development (years ago) and it is still marked as a TODO in the 
code. I have opened a bug report for it. It should get fixed in final 3.7.

     Thorsten, POV-Team

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