Welcome to lamps verses in missive materials in cycles.
So in this video you will learn the differences between the two light sources when using the cycles
render engine understand that there is a time and a place for both.
They both have pros and cons and finally will go on to use the blackbody node.
So let's hop straight on over in a blender.
Okay so we have our lamp here and if we render it as we had it a few moments ago we notice there's no
lights coming to it so we do want a light bulb inside our lamp.
Now there's a couple of ways how we can simulate this happening so we've got the three curse a 3D cursor
set there at the moment so we can literally go ahead and add a lamp into our scene.
That is a spot light.
Let's change this to solid for a moment so we can see the direction of the spotlight is currently down.
So I'm going to rotate that 45 degrees yes but it's roughly the right size as well.
Over in the spotlight options you can change a couple of items here.
It's strength we can see it's an admission that the colour coming out of it this size of the spot itself
and there are couple of other options there.
So let's just render that out and see what happens in faith.
I'm going to just render this area here where the lamp light is falling and we can see we get a relatively
clean lighting effect quite quickly.
Let's just move it around a little and see how that comes out.
Yes he's looking quite good but we're already at 30 with the number of samples accounting up here I've
raised my preview to about 100.
That's not bright enough so we can increase the strength here a little and see what we get then.
So that should give us twice the amount of light.
And in fact we can see there's a hole here and it looks like our position the lamp behind some think
so it's actually causing a shadow.
But you can see very quickly how we've got a nice quick defined line and it's not taking too long to
get out a spots on the floor but it's not as accurate as a mesh emission would be.
So there's places for both of these.
The actual bit of our scene that's lighting the main scene this plane over here in the sky.
This one here that is in a mission plane.
And it's basically casting light across our scene.
However if we want our spot light to be quite accurate we may use a lamp to do it.
So let's just let that render out now and see what it looks like after 100 samples.
In fact before we go and do that I'm not going to let let you be bored to much watching 100 samples.
I'm literally just going to hop in here and move our lamp.
Oh wrong lamp move.
The spot lights just move it's down a little to where a bulb would be.
Okay.
Brilliant.
So let's see how that works out when it's rendered.
Okay so we've reached a hundred samples there.
That's a really really crisp image really crisp spot light sorry that's going on there so I really like
that.
In the case of here if I wanted to use that I would attach it to the lamp itself parent it to the lamp
joint I think we've got everything going on there.
Now we've had a look at that.
Let's have a look at what an admission would be like.
So I'm going to hide our spotlight.
In fact I'm just going to delete it from the scene for the moment.
So it's not there at all not going to cause any problems.
And I'm going to use a circle.
So it's not too complicated mesh.
There's a circle.
I'm going to have to scale that in.
I don't know how small.
Probably Oh point eight again.
That seems to be a good number at the moment.
I'm just going to turn off render mode for a moment as well.
Okay so I'm going to have to rotate that around the x axis by 45 degrees.
I'm going to go to the side view again.
To see and move that down to around the same place as our lamp was and I'm going to hop into wireframe
mode to see where that is.
That's absolutely fine.
Now the moment is just a circle.
So what we're going to have to do is fill the circle in.
So it's got a face to it.
Now I'll hop into edit mode and add a face.
Now that looks like the face is actually the wrong way round but it doesn't matter at this moment in
time but there is an option that will make sure that the light only comes from one side of the plane.
We will worry about that at the moment.
We've got that set there and let's create a new material.
And I'm going to call it light bulb.
And it's going to be in a missive material.
And there it is on the node editors hiding away out of the way.
So I want to introduce you to this colour value here you can actually change the colour of the light
coming off of here.
And by default it's set to white.
Now we can control that colour values.
You can see there's a little entry point for it here.
So if we go in ad and it's all the way down at the bottom yet converter you can see here we've got a
black body and what that does is it enables us to give a colour temperature.
So if we link the colour outputs or the colour inputs of emission we can change the temperature of the
colour see if you know you've got a five thousand Kelvin lamp.
It will actually produce the right coloured light.
So now we've got that.
We've got an emissions strength of one.
Let's turn it up to 200 like the last lamp and let's render a similar scene as before.
Okay.
So that is a 100 sample render.
And as you can see it's a lot more noisy than the last one although it is probably more physically accurate.
Now we can play with the settings down here and perhaps increase the strength because it's quite a small
surface area.
And the way that light is calculated from an admission is the while this strength this value here is
based upon the area of the surface itself as we saw with the large plane when we originally set that
up for the lighting for the rest of the scene because it was so large we could get away with the strength
of only five.
But of course with this tiny bulb in the middle there.
We have to make the strength much larger if we want to bring to light.
So we see 100 samples.
It's still very noisy.
So over in the render properties here we can go down here and let's find samples.
I think of whizzed past actually sample samples sample sample samples is sampling here we get so in
the preview of it sets a hundred.
I'm going to now up that to something silly.
And of course Paul's video whilst it renders.
So we're coming up to around a thousand samples now and it's actually looking.
Dare I say a bit more realistic is not so such a concise spot and I don't think it would be coming out
of a lamp like that but it's a much more even spread of light.
Now I'm going to again pause a video but I'm going to just render the entire scene that we can see here.
Okay so just after a thousand samples and it's been a about 10 minutes render at the moment this is
just a viewport rendered not a camera based render like where we've done in the past and we can see
we are getting more and more of a spot appearing.
But it's taken an absolute age to do this.
So for accuracy I mean we've got the bright light where it's closer and then it fading off.
Obviously this is an orange background but the light itself is slightly orange as well from here.
And you know there's an argument both ways one looks one is accurate because that's exactly the light
you get out of that lamp shade whereas one is a fake spotlights so one's kind of faking it.
But it does depend on what you want to do and the power of your machine and the time you've got to render
it.
Obviously the more complex a scene you you've got to do.
I mean the other one had a realistic or not a realistic render a suitable render in 30 seconds or so.
This is already at 10 and a half minutes and it's going to probably just keep on going and going.
What have we got there another 15 minutes I am tempted to leave it to do that.
But at the same time I want to get on with the next stage of this as well.
So we'll leave it there for the moment actually.
Whilst that's rendering in the background I'm going to give you a challenge.
One quick thing that I'll mention before I do the challenge is that if we were to look inside the lamp
at the moment there would be a light in there if we were to look inside of the lamp with only a lamp
source a bit confusing with lamps and lamps here if we were looking inside the lamp.
When we had the previous spotlight generating the lights coming out we wouldn't see anything.
It would be dark inside the lamp shade itself.
So there is a distinct difference there.
So what you may want to do is do a small combination of both.
So it may be not turn the emission up quite this high but just have it in there so there is a light
source.
So if the lamp were to ever look in the direction of the camera at least then there is something inside
there because it would look a bit odd if when we were animating it you moved the lamp towards the camera
perhaps to look at the camera.
And then you find that it's dark inside there that would that would be a bit confusing for the viewer.
Okay so your challenge is to add your light bulb choose your light source for the bulb.
You can do both of course you can do a missive and a spotlight and then finally parent the light source
appropriately so it moves correctly.
When we move the lampshade pause video now and give that a go.
Welcome back.
Let's hop over in blender and sort that out.
Wow.
So back over in blender and I don't know if you can see what I'm seeing here but the screen's gone a
little bit funny looks like when I move the mouse over it it all comes back was that bit coming back.
I don't know.
I don't know whether Blender's going to crash because of this.
But I can still see it doing its render at the moment and it's not even reached at two thousand samples.
I'm going to obviously move my model round in a moment to show you one can do and I'm going to stop
that rendering.
Going to solid to change to stop it there.
But if we hop around now and have a look inside the lamp you will see that that circle that I generated
when we actually look inside the lamp if I hit Brenda it's white.
There is a light source there which is great.
That's is what we want and hop back into solid mode.
I'm going to use the origin of that some are going to move the cursor to their origins to shift S cursor
to selected.
I'm going to add.
I'm in edit mode I don't want to be in edit mode.
I'm going to come out of edit mode.
I'm going to add a lamp.
I'm being blind here lamp.
There we go as spotlight.
I'm going to take that round by forty five.
I'm happy with the light it casts from there.
And because we're working on the lamp now we can see we've got a lamp out on a mission.
I'm going to set it to the same colour temperature as before some going to add a black body.
So be a whole day body.
There we go.
And I'm going to link these two together.
And of course fifteen hundred would be a very orange type light.
I think we were at 5000 before.
However I will check.
So let's go to the circle that's on here five thousand.
That's absolutely right Kate.
So let's just do a very quick render.
I'm going to use control and be to go around here and just hit render and see how that comes out.
So we get a spot coming out plus all the other stuff in there so we can do to minimize that from happening
is.
We can go on to our circle and just turn the shrinks right down.
So I set that Sue I'm going to do a 100 for the moment we still get a little perspective.
But it's not going to cause us too much grief.
And when we look inside the lamp we've still got some.
I'm looking at it through the rest of the back drop there.
Okay.
I'm going to turn the emission down a little bit more I'm going to go to 50.
Maybe even less than that actually I am on the right thing yeah I'm on the circle.
Let's try one.
Okay that's great.
That adds something inside the lamp.
No that's far too dim.
Let's try 20.
Okay.
That adds enough detail in the lamp.
Is it causing a lot of speckling outside.
So I do want to be cautious of the amount of noise that's being produced.
No that's absolutely fine.
I'm quite happy with that.
Although I do want the strength of our lamp to come up the actual spotlights itself so let's going about
the spot and looking at this.
We've got a strength of 100 Let's turn up to 250 and see what we get then a much more defined spot.
Perfect.
So I've left that to render out for three thousand samples.
That's a bit higher.
No need for you to go that high.
And I just noticed a couple of things.
First of all I don't want to be quite this harsh so I can change a few settings there.
I did walk away to go grab a glass of water I didn't deliberately let it run for 3000 samples.
So now we go to the spotlight and go to the spot properties.
I'm just going to increase the size of our spots to 60 and that will give it a much larger circle.
So I'm happy with that.
Okay.
Now I'm going to increase the blend ever so slightly as well to make it just a little bit softer round
the edge maybe not quite that high.
Perhaps point five.
Okay.
Now that's done I just need to link both.
The lamp that we've just created this circle here I'm going to call that light bulb.
Okay so that's that.
And the spots now need to find the where is the lampshade joints.
They're both children of that.
I would just check really quickly if we click on the rig go into post mode which we're in I can't see
the rig at the moment so let's turn it on.
Excellent.
We need to grab one of the bones and that is the not the upper arm bone.
The next one down this one here.
Oh have we not.
Upper arms here are a one.
Let's rename that straightaway was respotted that's two lamp shade.
Excellent.
That's selected.
If I move.
Ah lamp abouts.
Excellent.
The spotlight moves as well.
That's exactly what I wanted to do.
Excellent.
So please share how you got on in discussions.
I'd love to see what sort of spotlights you guys came up with whether you follow this exactly or you
experimented a little.
Please share in the discussions and I will see you in the next lecture.