I don’t know much about the subject matter of the post, but it seems like the sort of blog that would notice that the earth and moon in the hero image rely on the sunlight coming from different directions.
Its done to split out clearly technically. Right is the specular component, left is excluding the specular component.
Right us basically if you shined a very bright light exactly from the angle of reflection. Left is more similar to if the scene had background lighting but not from the angle of reflection
Have you ever thought about making fresnel lenses out of rippling fluid? Like, sound in water or whatever. Making fine ripple pattern for lens or diff grate.
I don't know if anyone has used ripples in a liquid, but LCD's without polarizers are used in tomography to dynamically configure a diffraction or phase-shift pattern. https://en.m.wikipedia.org/wiki/Spatial_light_modulator
"And it turns out this happens because of a little thing called fresnel. [...] To account for this affect, you can use Fresnel [...] Certainly, PVC has a fresnel."
It's called Fresnel coefficient [1] after the physicist Augustin-Jean Fresnel. "Fresnel" is not a noun.
Each field can make up whatever jargon is convenient.
If we were talking about optics, then 'diffuse' and 'specular' would be adjectives that describe reflections. Fresnel reflection tends to mean specular reflection. The author sounds sensible when he recommends that specular reflections be implemented using Fresnel's math. That is how specular reflections work outside the computer.
I have expertise neither in physics nor in theater. But I do want to chime in to suggest that any time you're about to make a categorical statement like "fresnel is not a noun" in response to someone using it that way, it's worth pausing. Regardless of your certainty, there's rarely a well-grounded reason to think your view is more correct than theirs.
All language is contextual. Fields have jargon. And so many arguments on the internet arise when people from different contexts make unnecessarily strong statements insisting that their usage is correct. Instead, pause and consider whether there's a more valuable approach such as curiosity.
This person is confusing rim light on materials that are not perfectly rough with the fresnel effect, which comes from refraction at orthogonal angles that leads to reflection.
26 comments
[ 2.6 ms ] story [ 54.4 ms ] threadDoes this mean the author took two pictures: one with a polarization lens, and a second with the same polarization lens rotated 90 degrees?
I'm vaguely interested in what's going on here. For others who are interested, I think this reddit post has some technical details which relate to the topic: https://www.reddit.com/r/photogrammetry/comments/mfle5u/how_...
Right us basically if you shined a very bright light exactly from the angle of reflection. Left is more similar to if the scene had background lighting but not from the angle of reflection
It would be kinda programmable too.
https://iopscience.iop.org/article/10.1143/JJAP.24.L626/meta
[0] https://en.wikipedia.org/wiki/Talaria_projector
It's called Fresnel coefficient [1] after the physicist Augustin-Jean Fresnel. "Fresnel" is not a noun.
[1] https://en.wikipedia.org/wiki/Fresnel_equations
[2] https://en.wikipedia.org/wiki/Augustin-Jean_Fresnel
It is in stage and film lighting [0], which made this headline confusing to read.
[0] https://en.wikipedia.org/wiki/Fresnel_lantern
If we were talking about optics, then 'diffuse' and 'specular' would be adjectives that describe reflections. Fresnel reflection tends to mean specular reflection. The author sounds sensible when he recommends that specular reflections be implemented using Fresnel's math. That is how specular reflections work outside the computer.
All language is contextual. Fields have jargon. And so many arguments on the internet arise when people from different contexts make unnecessarily strong statements insisting that their usage is correct. Instead, pause and consider whether there's a more valuable approach such as curiosity.
"Can we change the Fresnel to get less reflection?"
"No, it's a physically-based renderer - change the IOR"
"but, that'll change the refraction angle..."
"Yep, split them into AOVs, and let comp deal with it."
Says whom?