Welcome to the for an owl married.
So what does this do.
Well it makes things more physically accurate and that is because everything has a friend nele effect
in the real world and we go into more about what that is.
In a moment now cycles does not do it by default so we have to mix some nodes together to make sure
we get the effect that we want.
Now one of the things to remember is that if your surface has a low roughness it has a high amount.
A friend now.
So for instance anything that's glossy is going to exhibit this more than something that is rough.
So a high roughness equals a low amount for a now.
So how does it function.
Well simply put it calculates the proportion of incident lights of the light that is coming in from
our lamps from the environment from whatever that is reflected off of a surface versus the amount that
does something else.
Now I say does something else because it does depend on what surfaces some of it will obviously be absorbed.
Otherwise you wouldn't see the surface if we were talking about water and liquids.
Well is going to go through the surface and start lighting up the base of the pond or the lake or whatever
it happens to be.
So let's have a couple of looks at some real world examples.
So here we have the roof of a car now.
Cars are pretty reflective in general and you see that closest to us where we're looking at it's almost
straight on.
There's less reflection then if we go further along towards the other car you can see in the background
there.
So we end up with more of the lights going through and hitting the paint underneath the clear coat on
top of the car as it goes round so we see more of the base colour as we go around and further towards
the top of the car.
You can see more and more of the sky so you get more and more reflection.
The lower that angle of incidence is to the viewer here we have another example of a car where we've
got we can actually see the blue of the car and as we actually go further and further away from are
our straight on angle we get a white and that's obviously reflecting the sky in the sun.
And what we can see here this is the four an l effect happening so depending on the angle you're viewing
depends on the angle of reflected light that you're going to see.
Now a classic example of the for an l effect is something along the lines of this where we've got a
gorgeous scene in front of us and we pay attention to the water because that is the highly reflective
surface of this is an example of something with low roughness as all the others have been.
But this is extremely low roughnesses is going to have a high for an l effect.
So closest to the camera where we're almost looking through the water obviously we can't look into the
water on this particular shot but you can see more of the bottom so more of the light is being refracted
and hitting the base of the of the lake here and then being reflected now as we go further into the
distance to the far end of the lake.
More and more of that light is being reflected rather than refracted and transmitted through the water.
Now here we have something that we've all experienced whether it's with a phone screen or a laptop screen
when the angle is not directly facing us.
We end up just seeing pure reflections of what's on the outside world rather than what we're trying
to look at.
This is something you can experiment with straightaway if you want to.
We can really see the effect in full flow.
So now we seen some real world effects of how the frenzel effect works.
Let's go explore this now and hop on over in a blender.
Okay so over on a default blend file now before I do anything else because I'm fed up of doing this
I'm actually going to modify my start-up file.
I want to select this lamp number of times I've now switched it to a sunlamp and change to the surface.
Use nodes.
That's NEWS NOTES here surface emission and set the strength to three the number of times I have had
to do something along those lines is getting a joke now.
So now I've done that.
What I can do is go ahead and save my start up far than the next time I go file a new.
It actually starts up with the lamp.
Perfect that's exactly what I want.
So when I go to rendered mode I actually get the bright uniform light across my scene.
I have to set up almost every time so I won't be setting them up any more because it's already done.
Okay so we've got our cube here and I'm just going to shift that back in our scene and again.
Well actually in this point what I can do is open up a previous file if I wanted to but I'm just going
to add a couple of objects into my scene.
Doesn't really matter where for the moment because we're going to see them reflected in the surface
in a few moments so.
One final object let's go for a cone.
Okay I'm going to turn snapping on so I can lift that up.
And the same with the cylinder and I'm just going to move that back in the cross slightly.
I'm going to put objects at slightly different places so I can see how the reflection changes with distance
in a few moments.
Kate.
Perfect.
I've managed to put that one relatively high.
The final thing I want to do is add in a plane along and scale that up to cover the entire lot.
The reason why I've added a plane is because this is going to become our reflective surface much like
The Lake is with the mountains and trees in it all in the background.
So all these low poly mountains and trees if you'd like.
So now we've got that setup.
I'm going to get rid of the tall shelf go into rendered mode make sure everything's working perfect.
Another shift this across so I can see still see what's going on in rendered mode.
But switch this one to the noda and I've gone to a vertical sort of workflow here rather than horizontal
and actually I'm going to get rid of those two will not get rid of them but pushed them to the side.
I'm going to add my alarm and make sure that selected the plane is selected and then create new material.
I am going to call this water doesn't have to be water but in this case it's going to be.
And we've got a set up here.
We've got diffuse going into a material output so that's the default material we've currently got.
So I need to show you guys where they're from l.a. is You might have seen it earlier if we go ahead
and add in input and friend now and there we go.
So that's now ready to be used in order to change the reflectivity of this surface based upon me angle
that you're looking at it.
Now one of the things we can do is actually hold down control and shift and click on for now and we
can see the effects in action so we can see that it's going to be a dark grey not black.
It will become darker and darker if you play with the Io.
Ah but we can see here it's dark grey when we're looking straight down.
So have a value close to zero.
And then as we get less and less as we start going down to a much shallower angle to that surface it
gets more white.
And as we can see here there's actually a gradient as well.
So we can see there that the which ordered to place things in as well.
We can see the gradient there from not quite zero maybe Point 1 or so on grey all the way up to one.
This will be white at the very top so that would be the most reflective.
So just set up the diffuse snoad as the main outputs again.
And then of course it's time for a challenge.
I'd like you to go ahead and set up for an l.a. SIR add the remaining shade as necessary to make the
friend node effective.
Remember we need a shallow angle furthest from the normal to be reflective.
And as we approach the normal off the surface for it to transition to another shader pause a video now
and give that a go.
Okay guys welcome back.
Let's go set up the four in l.a..
Okay so we're back over in blender and one of the first things that I need to do is decide on while
we need something reflective to begin with if we're going to make this work.
So let's go ahead and add in a gloss shader.
There we go.
So we now have two shaders to transition through.
So we need to mix these two together.
I'm going to use the node Wrangler shortcuts to do that.
There we go.
Got a shader plugged in and we need to change the front women factor here so where it's glossy or shady
so glossy here pure reflective just to test.
Of course I could use a control shift and click on it to us to isolate it.
Let's go back to the mix shaner.
We can see that the roughnesses say a point to so we're never going to get a decent reflection straight
off.
So let's lower that down to zero.
So we do get 100 percent reflection and we want it as we come up here to be.
Almost diffuse came with a tiny bit of reflection of course because it's not going to be there so that's
the factor in here and see what happens.
K. writes that is going the wrong way we can see that straightaway because it's not being highly reflective
when we're down here it's being highly reflective at the other end.
Kate So the next thing we need to do is swap these around then so let's swap them round if I'm going
to reorder them as well.
Just so it looks better.
It doesn't look nice if you've got things crossing over.
Okay so let's have a look at there now so it's diffuse all the way up here.
And it starts to get more and more glossy The further you come down.
Excellent.
Someone to drag this ball actually closer.
Oh it's.
Closer to us.
So we can see this far less reflection closer to the camera.
Then there is a way from the camera.
Okay that's perfect.
How did you guys get on did you play with certain things so we go back to the surface here.
Did you play with this Iowa to see what it does in fact.
Let's do that now.
I'm going isolate it first so we can see the pure what's actually going on so we keep it this shallow
angle so we can see almost no.
Oh no.
Glossy coming through it all the way up to gloss coming through.
So here we have an eye o are one point four five oh if we lower that down we see that we get more.
All in fact if we go all the way down we get pure white.
We don't seem to be able to stop going up.
So is most effective lowering it because we get a much stronger gradient.
So this is going to really emphasize the fact it's not going to be glossy close and glossy further away.
I'm going to go for a valuable 1.0 and then control shift click on the mix shader again and just see
what's happening.
Okay so as you can see here it's at this sort of angle these are very reflective.
Well let's make this bigger.
So you guys can really see what's going on.
So at this angle you can hardly see the reflection of this sphere but you can see the reflection of
everything else in the distance.
That's perfect that's exactly what I wanted to achieve.
How did you guys get on please show your work.
In the discussions and I will see you in the next lecture.