- [Instructor] Nuke has three types of lights,
a point light, a spotlight, and direct or parallel light.
The parallel and spot lights support shadow casting,
but the point light does not.
We're starting off the 3-D scene here
with no lights at all.
With no lights in the scene, you get a flat lighting model.
In other words, the actual RGB value of all
the texture maps is preserved in the render.
So let's switch to 3-D.
And then we'll pull back to take a look at our scene.
Whenever we add a light, the lighting model
switches to an 18 percent diffuse shading model.
I'll show you that.
Our lights are here in the 3D, lights, let's start
with a point light.
It lands at origin, throwing everything in the dark.
So, I can, in the screen, pick it up in y.
I'll move it back here.
I want it to be sort of behind and above the camera.
Maybe like so.
Alright, now if I look through my camera,
and lock the view finder, I can dial up the intensity.
We can even adjust the color.
And even dial in the fall off that we want.
Switching to the 2D view, it still looks like
the flat shading model, cause we haven't hooked the light
up yet to the scene node.
And now, the scan line render node will include
the light in its calculations.
Now in 2D, I can still adjust the light,
so if I wanted to move it over the right a little bit,
I can do that.
Okay, let's take a look at the direct light.
I'm going to select this point light and delete it.
And again, we go back to our flat shading model.
Let's switch back to the 3D view,
and add a direct light.
3D, lights, direct.
I'm going to go back to my default view, pullback.
Here's the direct light again, at origin.
So we'll pick it up, move it over here.
Now the thing about direct light, is it's actually
parallel light.
It represents the sun, a light source
at a great distance away.
So, the light is basically parallel.
So the position of the light is irreverent
when you're dealing with a direct light.
It is only the angle.
So, I can do a rotate x to point it down.
I could do a rotate y to angle it over.
Then, we'll look in the 3D view.
And dial up the intensity a bit.
There we go.
Now let's take a look at it in the 2D view,
after the scan line render node gets finished with it,
after we hook it up to the scene node.
Now I can fine tune it in 2D, by adjusting
the rotate y for example.
Okay, we're done with that.
So, we'll delete that.
Switch back to our 3D view.
Unhook our camera and let's add a spot light.
3D, lights, spot.
Again at origin, everything goes dark.
Pick it up, move it over, pull it back.
The thing about the spot light is, position matters
and angle matters, as well as the cone angle.
So, we'll start by roughing it in.
I'll go to the spotlight property panel.
I'll do a rotate x to angle it down.
I'll do a rotate y to angle it over.
So, it's roughly pointing at my scene now.
The spotlight, however, has one very unique feature.
I can look through the spotlight, exactly like a camera
lens, to make sure I'm pointed at my target.
Where we do that, is we come to our camera list,
and there's the spot light.
So like that, use command or control click on the 3D view
lock button to turn it green,
which means I'm in the interactive mode now.
So, I'm going to bring the property panel up here
with my transformations right here.
So now in the screen, I can adjust the angle
or the position of my spotlight
and it immediately updates all the transformation
and rotation values in the property panel.
Switching back the 2D panel now,
again hooking it up so it'll be included
in the scene calculations.
We can of course, dial up the intensity,
and adjust the cone angle and the penumbra angle.
The penumbra angle is how soft the outer edge is,
and the cone angle is, of course,
how widely it's focused.
And of course, in the 2D view, we can come
in here and rotate it in x to angle it up or down.
And rotate it in y to turn it off to the side.
All the while, getting an update in the 2D view.
Alright, let's delete the spotlight, go back to our 3D view,
and we'll pull back on the scene.
One more light in our light list is 3D lights, light.
Now the idea of the light node, is it actually contains
the point, the directional, and the spot
all in one node.
So if you set it to spot for instance, and the cone angle
and the penumbra angle will wake up.
The reason why you might want to use the light node
instead of the individual light type,
is it makes it easier for it to switch
between the light types.
Nuke lights are flexible and easy to add to 3D scenes
and are one of the key factors to achieving
photo realistic composites.