Le 2025-08-05 à 19:45, Cousin Ricky a écrit :
> On 2025-08-05 07:47, Mr wrote:
>>
>> could you please use conserve_energy keyword with your metals, as they are
>> currently so blindingly bright that I can't see the picture ! ;-P
> 
> Conserve_energy is intended for transparent textures; it is not relevant
> for metals (except maybe transparent aluminum).  The usual problem with
> legacy metallic textures is diffuse and ambient finishes that are too
> high, and that appears to be the problem with the typeball in this image.
> 
>> I wish Cousin Ricky's macros could be included in POV-Ray sources, so that the
>> default way of calling a metal would have all that hard-wired. because users
>> should be able to trust the defaults to not do that kind of thing.
> 
> I have proposed updates of metals.inc and golds.inc that use textures
> derived from RC3Metal.  I will probably submit a pull request when my
> Git learning curve levels off somewhat.  But this will also require a
> consensus resolution to the issue I raise in the p.beta-test thread
> "Ambient and diffuse for include files?"
> 
>> To sum it up
>> use fresnel, ior, conserve_energy
> 
> Fresnel, ior, and conserve_energy are for non-metallic textures.  For
> metals, the 'metallic' keyword takes care of all these factors.
> 
>> and a sum of diffuse+specular+reflection below
>> 1.(most clean and shiny metals should have very very low diffuse)
> 
> Diffuse+reflection should be below 1; specular albedo should be
> comparable to reflection, if you use use specular at all.  Yes, diffuse
> should be low, but I would add that the ambient should be even lower;
> the ambient-to-diffuse ratio should be no higher than for the other
> finishes in your scene.  For a purely metallic texture, both diffuse and
> ambient should be zero, though the world usually isn't that clean.
> 

I use ambient 0 for my metallic textures. I also tent to use diffuse no 
higher than 0.1, and that's for the dullest metals.

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