All right! We rendered the basic scene but now let's focus more on the lighting
part of it so far we've just put in a simple light but now I want to explain
more about lighting and maybe we can experiment with some different types of
light so if we go here back to our command panel and go to the create tab
the third option over is the lights you click here you'll see that there's a
drop down and there's photometric and standard lights let's start with
standard make it C target spot target direct Omni mentalray area Omni free
spot free direct skylight mental ray area spot first we will focus on target
spot if we go to the front view and we just drag from up above down on to our
still life and then go to the top view make sure it's in the right place you'll
have two surrett select both the target and the light they will move independent
of each other make sure that targets right on top of our area and then with
the light selected go into the modify panel let's go into an orthographic view
here and let's get it so that cone that cone is representing where the light
will shine let's adjust it so that it only shines
right on our scene if we go into the modify tab and go to spotlight
parameters you'll see us setting for a hotspot beam and fall-off field
Fallowfield is the outer ring which tells it where the intensity of the
light will start falling off and going to zero and the inner one is controlled
by this setting hotspot beam and you'll see if we want a hotspot right on or
still life and they'll put the fall-off about like that we can also go to
intensity and color let's make it something interesting like green has an
example something like that leave intensity at one one other
important setting that we need to make sure and adjust is under intensity color
and attenuation and that is the decay type decay type set to none means that
here and here the intensity of the light is exactly the same and that's not
physically accurate so only if you're trying to trick
the computer would you want to do that if you wanted to be physically accurate
which we normally do for going for realism then we set it to inverse-square
which from a physics standpoint that is what Lights actually do they start
falling off in an inverse-square fashion straight from the light source if you
want to fake the fall off you can use these here you can use near attenuation
and say that see these rings here that means that it's not to its fullest
brightness until 2 foot 3 away from the light and then far our generation would
be this is where the fall-off starts so at 6 foot 8 it will fall off and then it
will end at 16 16 foot a and the light will be 0 at that point so I'm not going
to use those I'm just going to let it fall off naturally using inverse-square
from the light source so that is a spotlight hits see to go to camera and
let's render real quick
okay you can see our other light is still there let's take that out so
you're only seeing our spotlight let's delete this one render again okay that's
what a spotlight is going to look like interestingly you can see some very
sharp shadows here and that is not really what happens naturally with these
types of standard lights you actually can't adjust the sharpness of the
shadows so that's why they're not very natural-looking and we'll have to do
some other things to add in more light to the scene to soften up those shadows
and make them less dark as well let's experiment with some other types of
light target direct or just a free direct the difference between target and
free by the way is just means one has a target like this here and if it was a
free spot it would not have that target and so it would just be adjusted by the
rotation of the light and that would determine where it points so that's the
only difference there Omni lights are just little point lights that will put
off light in all direction this is not something you use a lot if you want
photo realism because this is not something that would really exist in
nature if I put an omni light right there and we'll put that to purple so we
can definitely see it so that's intensity - - and now render again
nothing's happening let's see what we did wrong here it's outside of our scene
so that's not gonna help let's set it right here behind our scene behind our
still life and down below the table a little bit so that that light will just
emanate up from below hit C and render
okay that's obviously way too bright but you can see what that does that Omni
light puts things in all directions it looks like there's no fall-off going on
which is a problem you can see under intensity and color attenuation there is
no decay going on so let's put that to inverse-square and render again still
way too bright let's make it real soft 0.4 now it's looking a little better and
you can see that now we're catching a little bit of light up here but really
that's not a very good looking scene I want this much lower and I don't want it
so purple either
okay that's acceptable for now that's what the nominal Omni light does it just
puts things off in all directions puts light off in all directions again these
standard lights are not great if you're trying to get physically accurate
results but I'm gonna show you what they do anyway and then the direct light is
like a Sun okay so the direct light if you put it in here and drag it like this
this light will basically shine at the angle you put it at throughout your
entire scene so I'll show you what I mean by that it's like a Sun you can
think of it as a Sun s u n if we render that with that direct light in there you
now see that we're getting light coming almost from outside the atmosphere Ray's
coming at that angle throughout the entire scene that's what the direct
light will do and it's not a cone as you can see it is a cylinder of light like
that and of course you can still adjust the hot spot in the fall-off so that in
the olden days is what we would use for a Sun but there's better solutions now
we'll look at those in some of the later lectures but for now I'm just going to
delete this and we'll leave these other lights and in the next lecture we'll
look at some more physically accurate lights that cast nicer shadows and give
us more control over the quality of the light