small trunk

[thomas]

Hi Janusz,

Quick question: and why do you need such variation in material properties based on input? I know reflection changes based on the incidence angle of course, but I think this is already accounted for in the Fresnel node.
Which other optical properties change depending on the input angle? I read you wrote something about bump drop-off, so that's probably part of the answer, but I don't really know what you mean, and what other things change depending on the incidence angle (or other parameters).

[Janusz Biela]

Fresnel concerns also surfaces with textures. Very often you must mix Fresnel with texture in Nodes if any exists. You can do it by Mixer and Multiply blending. Of course input texture should have maximum Luma information for bright regions but not that strong to receive white. Real information about reflection comes from Fresnel but Texture input gives us surface reflection fractions.
Example:

ScreenShot180.png (9.6 KiB) Viewed 1472 times

So also visible region which has less reflection (it is natural for wood when some parts are polished some not or bathroom tiles where rampart has no refletion and by black colour is excluded from reflection).
The level of this input depends from your experience: how you feel material and how you extrapolate it from real life into Nodes. In other way: watch around you and try simulate, after a couple months you will get it in few seconds.

Here example how should be mixed Fresnel with reflection map:

Bump drop Off is just incidental angle dropping bump level.