Is it just me - or do other people encounter problems trying to make certain portions of a material shiny with this parameter? I’d think it would work just like a bump map but it never does from my experiences.
I typically use Falloff Fresenel in the reflection map.
post some example images?
can you clarify juju?
The few test I have done in the past it usually works just fine. Just make sure you untick the little L next to highlight glossy so that its not locked to the same as the reflect glossy. Having a map in the slot does not override this.
using a falloff Fresnel map in the reflection slot it’s EXACTLY identical to simply tick the “Fresnel” by the reflection, provided the map IoR and VRay’s are identical. Using that map should be confined to obtain a behavior which is not physically correct, but looks good (shaded/lit mod, perpendicular/parallel, towards/away, distance and so on).
It’s perfectly correct to unlock the reflection and refraction IoR as the reflection is oftentimes coming from coatings of various types (anti-glare treatments of glasses, coatings on car paints, lacquering and so on) and those have a IoR which is their very own, not related to the underlying object.
Both things i observed personally, not law cast on stone…
Lele
^Personally, I always use a falloff for it so that Ive got more control. Even if I dont intend to use it, I find its nice to have the map already there just incase it needs tweaking.
Also, works like a bump fine over here.
Bear in mind the values used, and the range they go up to.
Sure.
But when you have 200 materials, and have to check which map is which, and which is active and tweaked, and which is not, it’s a LOT of clicks you have to do.
I add it ONLY if i plan to change the fresnel curve, or to obtain a different effect (typically some rimming).
In that way, when something goes wrong, i have a lot less to troubleshoot…
Lele
Is a default value of 1.6 with Fresnel Checkbox ticked the EXACT same as a Falloff Fresnel Map set to perpendicular with complete Black and White Channels?
And what are the corresponding IOR values?
Nope - I’m not sure if any ior will do the same as a perpendicular / parallel - they seem to have less range of reflection in terms of the side / facing ratio.
You cant have a Falloff Fresnel Map set to perpendicular. Either one or the other. Youll notice in the falloff map, that the IOR, even though grayed out says 1.6. So if fresnel is enabled in the map, itll be identical to the vray fresnel as long as you dont mess with the black and white ranges.
Also might be obvious, but if you have a falloff map in your reflection slot, dont check the fresnel box or itll further subtract your reflection amount.
Thanks John and Percy. I figured out as much on the Percy’s points - but John is hitting my second question (Aside from highlight reflection) on the nose. So the two methods cannot be compared then - that’s what I had thought and hence why I never used the built-in Vray material’s capabilities.
But my question remains about the highlight reflection and if these methods have a major impact on this parameter. I don’t have any current examples to show.
Re: Highlight Glossiness
It’s either Fresnel mode, or Perp/parallel mode: the two are exclusive modes of the same Falloff map, as Joconnell and Percy said.
So the two methods cannot be compared then
Fresnel is the same as the vray’s one (provided colour and curves are not altered, and iors match), Perpendicular/paraller is not.
You original question spoke of Falloff Fresnel, not perpendicular mode.
In either case, no problem to report here:both ways work as they should, imo.
Lele