Why do people use falloffmaps set to fresnel in the vray material?

[Morne]

This thread is making me think of "Rush Hour" where Chris Tucker tells Jackie Chan: "My daddy will kick your daddy's ass"

[tricky]

This thread is making me think of "Rush Hour" where Chris Tucker tells Jackie Chan: "My daddy will kick your daddy's ass"

Hahaha. Yes!
This is why I 'usually' write things like "I think" or "in my opinion" in case I am wrong (and I usually am!!!). So, in the film Rush Hour, I would say something like:-
"I think my daddy will kick your daddy's ass" or "My daddy will kick your daddy's ass, in my opinion"!

[DPS]

So people would tend to use one or the other and not both in conjunction?

Just asking for general learning.

[Morbid Angel]

I thought that direction of reflection was based of of surface normal not from IOR?

[Dariusz Makowski (Dadal)]

Direction of reflection is based on surface normal UNLESS there is bump/normal/displacement.

IOR only control the strength of the reflection.

[insleight]

I smell bullshit. I dont know where it is but i smell it. I never use the falloff map option for fresnel. If i want more front facing reflection i simply increase the ior. If i want to reduce the glancing angle reflection i turn down the reflection value in the color slot. Thats how i work at least.

[Dariusz Makowski (Dadal)]

Uhh well do a simple test. Make front faces more reflective than glancing faces. You see you will need to use Fresnel map wit inverted values. U cant get it by simply lowering valus of color slot..

[joconnell]

Bingo - with ior / fresnel you've no control over how quickly the strength of the reflection ramps aside from basic less or more. With falloff I can totally art direct the look of my reflections as they wash over a surface so you can push things around a lot.

[simmsimaging]

My guess is that if you don't already know why you need this map then you probably don't really need this map

I use it fairly frequently, but rarely for simple materials. Beyond the obvious, it is also useful as a blend map in a VrayBlendMaterial to create layered reflections.

/b

[DPS]

I dont follow that logic, im trying to improve my shaders - I think this is quite handy.

[vlado]

While the falloff map is useful in many situations, I would just like to point out that it has some slight performance penalty, which perhaps needs to be taken into account.

Best regards,
Vlado

[joconnell]

With that idea in mind, and the other time penalties associated with rendering inside of max, would it be worth looking at replacing some of the common map types and gradually trying to move people towards the standalone? Admittedly it won't work for everything with max plugin support and what not but would it a long term aim? Ideally go the route of other renderers of a single core and a set of translators for each app? Vray for maya and XSI are kind of based around this principle aren't they with max being the most heavily integrated version?

[DanielBrew]

Didn't there used to be a VRay fake Fresnel texturemap buried inside VRay somewhere?

[Dariusz Makowski (Dadal)]

Tha texture is exposed in Maya. I guess max would need some max scripting to get it ?

[DanielBrew]

I think that's how I found it. I just wondered if there was any reason why we shouldn't be using it.