browsing in the Material Room, the edge blend is used pretty often.

how can I put it to work for me? 

Does it blend the edges between 2 material groups?

so, if i wanted to blend for example, between the lips outline or eyeshadow makeup and the rest of the Skin texture,
would this be an application for the node?

Thanks. 
getting ready for a 3 day weekend of beer and poser.

Here's a quick example: the inset is the hires ball with the edge blend.

Laurie

(edit) response to OP, before LaurieA posted!

No, that's not what it does.

 

It blends two different colour values according to the angle between the camera view and the surface 'normal' (an imaginary line pointing outwards perpendicular to the surface being rendered).

The "inner colour" is what it produces when looking straight at a surface (along the normal), and the "outer colour" is what it produces when looking along the surface (at right angles to the normal). The attenuation controls the transition between these values.

 

The edge blend "colours" are often just used as arithmetical values to control some other effect that varies according to the camera angle, such as reflectivity, or specular highlights.

 

it makes an edge on your objects. it depends on your camera angle. its used a lot of times for the fresnel effect (skin,metal,car pain,plastic,...).
you can also use it for some effects.

@ IsaoShi,

Thanks for that very clear and concise explanation of edge blend. 

Try these threads about Nodes

http://www.runtimedna.com/forum/showthread.php?p=186776
http://www.runtimedna.com/forum/showthread.php?p=76734
http://www.runtimedna.com/forum/showthread.php?p=86840

oh the Node Cult.  I forgot all about them after RDNA was down for their revamp.

Thanks!

The Edge Blend is a tough one.  Maybe I should've started with the Gloss node.

It's not so tough really... try this. Here are two beautiful spheres (click to enlarge). (with special thanks to Ms Poly Gonsmoothing).

The left sphere has 100% reflectivity over its whole surface (just a Reflect node).

The right sphere has an Edge_Blend node (see diagram) controlling its reflectivity, by plugging its output into the Reflection_Value channel.

The Edge_Blend Outer_Color is white, meaning that when you look along the outer edges of the sphere (along the surface) the number plugged into Reflection_Value is 1.0, or 100% - and it is just as reflective at its edges as the other sphere.

The Inner_Color is black, which means that when you look at the inner part of the sphere (directly at the surface) the number plugged into Reflection_Value is zero. So there is no reflection here.

I also used the Edge_Blend node to increase Diffuse_Value at the same time as reducing Reflection_Value, by passing it through a maths subtract node. So as the amount of reflection decreases, the diffuse colour shows through.

A higher Attenuation value in the Edge_Blend node gives a quicker transition from the inner colour to the outer colour. On this sphere it would have the effect of reducing the spread of the diffuse colour from the centre and giving us a wider area with high reflectivity.

Notice the reflection of the right sphere in the left sphere. You can also see the Edge_Blend effect here, seen from the different angle.

Oh bother - this is the picture I should have posted. That other one had a plain floor that shouldn't have been there. The reflections are clearer in this one.

A little quiz... how many raytrace bounces can you see in this image? Look carefully at the right sphere!

I'm not sure, but I'd like to know. I'd like to know your lights, material and render set up. That's such a wonderfully clear and sharp demo render!

I would guess 4 bounces (at least) because I can see a reflection of the edge blend effect in the reflection of the reflection in the right ball.  (Too much recursion here......)

edited to add:  And I forgot to mention that this is an excellent demo - Thanks!

edge blend also useful for toon shader lines without postwork.  olivier is selling one of those at rdna IIRC.

Quote - I would guess 4 bounces (at least) because I can see a reflection of the edge blend effect in the reflection of the reflection in the right ball.  (Too much recursion here......)

edited to add:  And I forgot to mention that this is an excellent demo - Thanks!

I'm happy to help. :O)
4 bounces? Close, but not quite... although your recursion count is correct!

I'm still at work right now, but I'll be back later to explain my setup. It's a very basic scene and lighting setup. The only complicated thing here is my parameter-controlled 3D tile shader. I'm still working on getting the reflectivity right on this shader - using an Edge_Blend node for the Fresnel effect, as it happens.

I was wondering... should I post these details in a new thread? Would it be going too OT with regard to this thread? Would anyone else be interested in my little test setup?!

What do you think? :unsure:

I'd sure be interested!

I'm interested as well....

Here you go...  I'm not sure exactly which bits are of interest, so I wrote everything I could think of in the attached text file. It's just the setup that I used for the demo renders, and in no way intended as advice on what settings you should use for your renders of your scenes. I'd be happy to answer any questions about any of the settings, though.

To be honest, simple surfaces like this in a bright test setting are fairly easy to light well, as long as you gamma correct.

I think the main points are that I used gamma correction (Poser Pro), an HDRI background image on bagginsbill's EnvSphere, a matching HDRI light probe on the IBL light, an ISF light just above the two spheres, and a standard spotlight to the right of the camera.

The materials for the spheres were as posted earlier, except the left sphere has only the Reflect node and zero diffuse colour. The tiles are a shader I am still working on, to be a freebie if I ever finish it.