Original subtitles

Of course there are a few other properties of the key light that we haven't touched yet, the

color temperature and propagation to name a few. the easiest way to control the color of

the light source is obviously to use the RGB Color picker, a cinematography analogy would be placing a

gel over the light source to make it any color you want or let's say using an RGB LED panels.

so that was color wheel, the first option that we have.

alternatively if you are in the mood of dealing with the color temperature directly you can

click the use nodes button and then this dot near the color and choose blackbody.

the blackbody node converts the temperature in kelvins to the RGB data, basically this slider

controls a type of radiation or light color emitted by a black body or a light source

when it's heated to a certain temperature, these temperatures are measured in kelvin, the hotter the

temperature the more blue the light appears, the temperature of 5200 makes it look like a daylight

6500 is slightly cooler than that, it's like an overcast daylight, so yeah basically the higher the

temperature the bluer the color. it is a standard way of dialing in the color of the light source, of

balancing the light bulbs in cinema production, you name it, with that being said to keep things simple

I will remove this node for the time being and rely on our good old color wheel instead.

I will dial in the neutral white color with the saturation of 0

or using the RGB model it should be 1 in both red green and blue. okay...

the last slider that we haven't explored yet is the beam shape spread. as its name implies it's a

tool for shaping the directionality of light and it can be imagined as focusing the beam basically.

from the default 180 degrees all the way to 1 degree which makes it super focused.

it is also important to note that it does correlate with the perceived softness of light,

the smaller spread value does make the shadows harsher. I think we are good with the default

spread value of 180 so I'm going to Ctrl Z it all the way back and let's imagine if we

wanted to control the spread or propagation of the light beam, what else could we do?

we could have used um some kind of a blocker, just a regular plain object or a box, we could

have simply blocked or cut the part of the light rays to better control the propagation,

actually we will dive deeper into shaping the beam of light later on in the course, in

the second chapter where we will use different kind of blocking techniques as well as light

textures and dappled light techniques, that is a little teaser, so obviously stay tuned ;)

meanwhile because we utilize a physically plausible path tracing render engine such

as Cycles we also automatically add some fill light in addition to our key light, just like it

happens in a real world production. so as we crank up the power of our directional light component

it also affects the power of the bounce. we can tell that the drop shadow part of the minerals

isn't pitch black, it's because some part of the light rays got bounced or reflected

by the environment. there are two types of bounces, diffuse and glossy and if we dial in 0 in both

we will see what we would see in Eevee, let's say, we would see the pitch black shadow.

as soon as we bring back some of the light bounces and let Cycles do its light transport

work, the shadow will get filled in a little bit and it totally depends on the power of the light

source, it works in proportion to the power of the key. I suppose it should be super intuitive

and feel like home if you worked with physical light sources in production. and again with no

light bounces it will look just like Eevee so let's switch over to Eevee for a second just for fun.

to make it look indistinguishable from Cycles the soft shadows in Eevee should be set to on

and then within the light settings tab the contact Shadows should be ticked,

otherwise the Shadows won't be precise enough. to double down on this, Cycles with zero light

bounces looks very similar to Eevee, but once the global elimination kicks in, Cycles path

tracing gives us a nice fill in addition to the key light in the form of the indirect bounce

that being said further down the line in the monastery dungeon chapter to be exact we'll

discuss the global illumination methods for Eevee, namely it's built Irradiance map as well as

a real-time screen space Global illumination or SSGI. consider this a quick teaser :) Eevee

is a great render engine after all and it will get its time in the spotlight (no pun intended).

it is so cool but still I'm gonna switch back to Cycles in a moment

personally I love a physically realistic way the secondary light bouncers are calculated in Cycles,

it's not that different from manipulating real light sources and I think it just

matches our learned expectation on realistic light transport, the secondary bounces specifically.

it is a cool little effect that adds believability to everything, the photons bouncing around

the scene and filling in the shadows, well, not literally but something like that :) the amount of

the bounce light is again always in proportion to the amount of the directional light and it makes

the balancing of these two components really easy and intuitive, it's like a nice contrast

ratio right out of the box. okay now I will dial back the power of our key lights to 3700 Watts.

now everything about our main light feels right to me, we can start adding some detail I think.