Fresnel Reflections

Mga sir para san po ba ang Fresnel Reflections?
salamat po

hmm.. ang hirap iexplain ang Fresnel effect.. parang ganito na lang.. kapag nakatingin ka sa mahabang kalsada.. sa malayo parang basa ang daan.. pero paglapit mo sa parang basa na daan ay tuyo naman.. ganun ang Fresnel effect.. kapag naka angle mo tinitingnan ang surface parang nagkakaroon sya ng reflection effect..

isang example pa ay sa isang hallway o corridor na walang carpet.. kapag sa malayo kita mo reflection ng walls sa floor.. pero kapag tumingin ka sa floor kung saan ka nakaapak di mo naman Makita sarili mong reflection..

sana naintindihan mo hehe kung di mo pa rin maintindihan google google na lang tungkol sa Fresnel reflection

salamat po sir sentido madali kong naunawaan hehe

Napangiti ako sa explanation ni sentido. 
Somehow correct and wrong...

Sa concrete roads or asphalt roads, they sometimes mix particles of glass for friction (thats how it is in Japan...). They are randomly spaced as they are mixed with asphalt. So if you look at them from glancing angles specially if you're far away, they tend to look compressed and you no longer see the spaces between them so what happens is that the surface tend to be more reflective...

Fresnel among reflective surfaces work like magic in the sense : if you are looking at it in parallel - the lesser the effect (or even zero) becomes. If the viewing angle is perpendicular it then becomes more prunounced..

The reverse is thru for refractive surfaces....

I think I may have discussed that in here long ago just can't remember where to find the thread..

sir wranger pwede po ba mag request sa inyo ng sample output ng may freshnel reflection? salamat po

To learn more about real world materials,  you may read the previous discussions:
http://www.cgpinoy.org/t14145-real-life-examples-for-computer-graphics-imaging

Technically, reflective objects other than a full mirror exhibit changes in their reflective properties based on where you are viewing them

As an example, here's a simple object with full reflection ( only for mirrors!) 


If you look closely, the reflections are evenly distributed along the surfaces (this is how mirrors behave)

And the same object with the fresnel properties taken cared of (there's a checkbox for fresnel reflections in vraymats) but I prefer using a falloff as a mask in the reflection slot.



Notice that as the reflections are stronger along the edges of the objects and as they move away, slowly fade out. 

I will not tell you which one looks closer to real life but the latter is how I normally manage reflective surfaces...

As a final test, hold any reflective object (bottles, mugs, etc) in  front of you and try to notice the behavior I wrote above...

ok thank you so much sir v_wrangler