Am 06.09.2015 um 07:37 schrieb Mike Horvath:
> On 6/9/2015 2:12 AM, clipka wrote:
>> Am 09.06.2015 um 07:41 schrieb Reuben Pearse:
>>
>>> I've tried rendering them using UberPOV, but I'm getting a really
>>> "grainy"
>>> image. I'm guessing it's to do with the radiosity settings (or the
>>> subsurface settings?).
>>>
>>> Do you have the details of the final render settings you used for your
>>> image?
>>
>> No, I don't recall what settings I used; but the highest-quality
>> settings suggested in the comments (+am3 +r9 +a0.002 +ac0.99) should
>> kill the graininess in any image(*).
>>
>> (*unless it's /designed/ to be grainy, of course ;))
>>
> 
> Is this the only way to get rid of the speckles? The render is
> unfortunately taking too long at the highest quality settings.

I presume you're talking about noise-like speckles.

Generally speaking, there is no way around those speckles except for
shooting more rays. The most simple solution to achieve this is indeed
to use "anti-aliasing" mode 3 and increase its quality settings, but
there are other places to tweak:

- If the grainy speckles appear to be related to radiosity, increasing
the radiosity "count" parameter might be a more efficient way to reduce
the speckles. Note that you can also use the radiosity importance
mechanism in this case.

- If the grainy speckles appear to be related to subsurface scattering,
increasing the subsurface sample count might be a more efficient way to
reduce the speckles.

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On 9/6/2015 8:24 AM, clipka wrote:
> POV-Ray is perfectly fine with multiple global_settings blocks,
> especially if they contain entirely different settings as in this case;
> if one setting would appear in both blocks, the second one would
> generally win (but until then the first one might have an influence on
> parsing).
>

That's good to know.

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I've tried applying your settings to my own scene, but am not getting 
any reflectivity off the bricks. Could you take a look? The finish is 
defined in "l3p_materials_noshadow_1.4_uber.inc" at line 58. Thanks!


Michael

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Attachments:
Download 'lego_building_povray_20150916.zip' (94 KB)

I just noticed I forgot to copy your global_settings. But after doing 
that I still can't see much reflectivity. I'll post again with an update 
when my render is complete.


Michael

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> I've tried applying your settings to my own scene, but am not getting
> any reflectivity off the bricks. Could you take a look? The finish is
> defined in "l3p_materials_noshadow_1.4_uber.inc" at line 58. Thanks!
>
>
> Michael

When you use "fresnel", you also must provide an interior block where 
you set the ior for that material.
If you don't, the ior default's to 1 whitch prety much kill reflectivity.

A good starting point for the ior is in the range 1.4 to 1.8.
Water's ior is about 1.3.
Most plastics are in the 1.45 to 1.67 range, same for common glass.

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On 9/17/2015 5:17 PM, Alain wrote:
> When you use "fresnel", you also must provide an interior block where
> you set the ior for that material.
> If you don't, the ior default's to 1 whitch prety much kill reflectivity.
>
> A good starting point for the ior is in the range 1.4 to 1.8.
> Water's ior is about 1.3.
> Most plastics are in the 1.45 to 1.67 range, same for common glass.


Thanks for the tip.

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I've attached my latest experiments using your settings and the LGEO 
library. Things seem to be working okay. I'll post my render when it's done.

Michael

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Attachments:
Download 'lego_building_povray_20150917.zip' (51 KB)

Am 17.09.2015 um 23:17 schrieb Alain:

>> I've tried applying your settings to my own scene, but am not getting
>> any reflectivity off the bricks. Could you take a look? The finish is
>> defined in "l3p_materials_noshadow_1.4_uber.inc" at line 58. Thanks!
>>
>>
>> Michael
> 
> When you use "fresnel", you also must provide an interior block where
> you set the ior for that material.
> If you don't, the ior default's to 1 whitch prety much kill reflectivity.

Actually "pretty much" is an understatement; "totally" would be more to
the point ;)

> A good starting point for the ior is in the range 1.4 to 1.8.
> Water's ior is about 1.3.
> Most plastics are in the 1.45 to 1.67 range, same for common glass.

Solid LEGO bricks are made of acrylonitrile butadiene styrene (ABS),
while transparent LEGO bricks are made of Makrolon, a polycarbonate
(PC); for both families of plastics, an ior of about 1.6 is a very good
approximation.

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On 6/5/2015 5:51 PM, clipka wrote:
> Am 05.06.2015 um 23:39 schrieb clipka:
>> Am 04.06.2015 um 23:17 schrieb Reuben Pearse:
>>
>>> I would like try some more UberPov renders using the LDraw models that
>>> I've
>>> already converted to POV-Ray - could you share the full code for your
>>> example picture.
>
> Here are the files that make up the scene. I might have made some minor
> changes by now.
>
> NOTE: The include file "lego_colors_.inc" is NOT INTENDED FOR FURTHER
> DISTRIBUTION without my explicit consent. There are reasons I don't want
> it to be spread around outside this newsgroup.
>

How do you tone down the scattering in the reflection? I want it to be a 
little more sharp.


Michael

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Am 22.09.2015 um 05:27 schrieb Mike Horvath:
> On 6/5/2015 5:51 PM, clipka wrote:
>> Am 05.06.2015 um 23:39 schrieb clipka:
>>> Am 04.06.2015 um 23:17 schrieb Reuben Pearse:
>>>
>>>> I would like try some more UberPov renders using the LDraw models that
>>>> I've
>>>> already converted to POV-Ray - could you share the full code for your
>>>> example picture.
>>
>> Here are the files that make up the scene. I might have made some minor
>> changes by now.
>>
>> NOTE: The include file "lego_colors_.inc" is NOT INTENDED FOR FURTHER
>> DISTRIBUTION without my explicit consent. There are reasons I don't want
>> it to be spread around outside this newsgroup.
>>
> 
> How do you tone down the scattering in the reflection? I want it to be a
> little more sharp.

Change the "PlasticRoughness" variable to a lower value.

Note that this will affect both reflection and highlights, and for the
sake of realism that's how it should be.

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