POV-Ray : Newsgroups : povray.general : Solar Panels glint problem : Re: Solar Panels glint problem Server Time: 17 Jan 2021 05:18:23 GMT
  Re: Solar Panels glint problem  
From: Cousin Ricky
Date: 20 Nov 2020 16:25:21
On 2020-11-20 8:24 AM (-4), Gabriele wrote:
> 
> These are the finish properties given to the solar panels, together with a
> Polished_Chrome texture:
> 
> Ambient: 0.0001
> Diffuse": 0.0001
> Specular: 1.0
> Roughness": 0.00001
> Reflection": 1.0
> Brilliance": 100.0

The smaller your roughness value, the less specular highlight you get. 
To counteract this, use specular albedo.  I suspect this is the main 
problem.  You might also need to increase roughness to, say, 0.0001.

Reflection + ambient + diffuse should never be more than 1.0.  However, 
your values ambient and diffuse values are so small it should not make a 
difference.

Ambient should normally be much smaller than diffuse.  And since in 
outer space, the only significant source of ambient light comes from 
Earth, at the geosynchronous distance ambient should be even tinier, the 
exact proportion depending on how much of the sunlit portion of Earth is 
visible from the satellite.  But again, your values are too small to 
make a difference.

Brilliance is irrelevant with such a small diffuse value.  But since you 
are looking for a specular effect rather than diffuse reflection, 
brilliance is the wrong knob to tweak.  You should leave brilliance at 1.0.

Since your settings override all the Polished_Chrome values except the 
Phong settings (which only complicate the highlight situation), you 
might as well drop it and just use pigment { rgb 0 }.  Or rgb 
<whatever-is-silicon's-albedo>.

Your settings are also physically unrealistic for a solar panel, 
although this does not relate directly to your problem.  Unless you are 
using Fresnel reflection, the reflection value should not be 1.0, 
because if you reflect all of the light, none of it gets to power the 
satellite!  But for glass, you should be using 'reflection { 1.0 fresnel 
} conserve energy' anyway; this allows a realistic amount of energy to 
be transmitted to the solar cells.

Unfortunately, POV-Ray 3.7 does not implement the Fresnel effect for 
highlights.  To get a good average highlight, use 'specular albedo 
0.05'; but at shallow angles, for example, looking towards the west 
after sunset, specular albedo should be closer to 1.0.  POV-Ray 3.8 can 
take care of all these complications: use 'fresnel 1.0 reflection { 1.0 
} conserve_energy specular albedo 1.0', making sure that the fresnel 
keyword is *outside* the reflection block.

> Does anyone know how can I make them shinier? Is it a problem related with the
> material or is it due to the very low FOV?

I have had problems with low FOVs, but they have affected only geometry, 
not material properties.


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