Specular material: reflection and transmision?
Posted: Thu Nov 19, 2015 2:20 am
Hi,
i'm trying to model a realistic human eye, using a physiological eye model including lenses, IORs etc. and i'm not using any exporter but generating indigo script files using a python program (the model is parameterized).
I'm trying to better understand how the reflective type of materials work, in particular to model the cornea which has material properties which are between glass and liquids.
So far the glossy-transparent worked reasonably well, but i'm now having a scene where the image of a light source ("glint") should appear reflected in the eyes, but it doesn't because the light source is shining in the eyes through a mirror.
I am under the impression that the glossy-transparent specular highlight works like in the Phong model, and it shows highlights only generated by direct rays (not reflected) is that correct?
If i want to get the glint of the reflected light source, it seems i have to use the Specular material, but i haven't found a proper way to control which percentage of the incoming light power is reflected and which is refracted.
My current workaround is to use a Blend type which includes a purely reflecting Specular material and a purely refracting Specular + transparent + Arch glass; i can then use the Blend factor to control the reflected energy vs the refracted one.
But this renders extremely slow.
Is there a proper way for the Specular material to set Reflected and Refracted ratios?
Thanks,
Walter
i'm trying to model a realistic human eye, using a physiological eye model including lenses, IORs etc. and i'm not using any exporter but generating indigo script files using a python program (the model is parameterized).
I'm trying to better understand how the reflective type of materials work, in particular to model the cornea which has material properties which are between glass and liquids.
So far the glossy-transparent worked reasonably well, but i'm now having a scene where the image of a light source ("glint") should appear reflected in the eyes, but it doesn't because the light source is shining in the eyes through a mirror.
I am under the impression that the glossy-transparent specular highlight works like in the Phong model, and it shows highlights only generated by direct rays (not reflected) is that correct?
If i want to get the glint of the reflected light source, it seems i have to use the Specular material, but i haven't found a proper way to control which percentage of the incoming light power is reflected and which is refracted.
My current workaround is to use a Blend type which includes a purely reflecting Specular material and a purely refracting Specular + transparent + Arch glass; i can then use the Blend factor to control the reflected energy vs the refracted one.
But this renders extremely slow.
Is there a proper way for the Specular material to set Reflected and Refracted ratios?
Thanks,
Walter