In the last video, we covered how we could utilize PBR lights to not only light
our scene, but to act as soft box shapes that can be reflected by the objects
in our scene. Now, this helps make for some really nice reflections, but there's
another way to easily add an environment to our scene for our objects to reflect,
and that is to utilize HDR images. Now, HDRI stands for a High Dynamic
Range Image, and they allow you to be able to use a high-quality image with loads and
loads of luminance depth as a source for not only reflections, but as a
light source. Now, before we begin, make sure you're in your interactive
render region by hitting OPTION+R, and now we can go and start loading up some HDRIs
and see how it changes the look of our render. So luckily for us,
there is a whole bunch of free HDRIs in the content browser.
Now, if I go to Window and go to the Content Browser, and head over to the
Presets menu, you're going to navigate to Prime, twirl that down,
go to your Presets folder, twirl that down, go to light setups, and go
to HDRI. Now, that was quite some digging but we are here, we have all of our
HDR images. And you can also slide this up to really get a bigger preview of what
these HDR images are. And you can see that some of them are just big 360-degree
photos of environments in a city, or in someone's backyard, or something that
resembles a photo studio, especially this photo studio right here
where we have some umbrella soft boxes. So, that gives you an idea of what an HDR
looks like. Now, how we can add them to our scene to be used as a reflective
source is we'll just go ahead and let's use this Photo Studio to start.
So I'm just going to click and drag and drop that into my material manager here.
And I'll close out of my content browser for now. And now to be able to use this
as an environment, I need to go and grab myself a sky object.
So, in this little menu here with the little grid floor, you can grab a sky.
And this is going to act as a giant sphere that's going to act as a spherical
environment that our scene is going to live inside. And all we have to do is go
and drag and drop this material onto our sky, and voilà. You can start to see those
little umbrellas, those soft box umbrellas, being reflected in our scene
and onto our objects. So, this is a really easy way to add more
detail to your reflections and make your image look a little bit more realistic and
more interesting. Now what we want to do is maybe test out what
each HDR does to affect how our image looks. Because they're being used
as reflections, how our reflections look can be heavily influenced by these images.
So let's try this other photo studio. And while we're at it, let's grab
maybe one of these tree scenes, and maybe the sunny neighborhood scene.
So I just want to demonstrate how different your image can look, or your
objects can look, depending on which image you're using for your HDR.
So, I'll just drag and drop and replace the existing material tag on the sky.
And you'll see, as this updates in the interactive render region here,
that we actually lose those really nice soft box shapes, and this really isn't
adding a whole lot because of the way that our sky object is orientated.
Now, what we could do is maybe we can rotate the actual image or offset it.
And you can actually see how it's being represented on that little grid there.
So basically, I'm just offsetting the texture and moving it along this
giant sphere. And you can see that I've offset it to a point where we can see this
little block, this little soft box bit right there. So let's go and use an actual
image from real life. And we should start to see the nice little tree details
that were in that HDR image. Let's try the sunny one.
And again, we get different details still. So, another nice thing you can do,
if I go and just grab this photo studio again, and maybe zero out that offset
as well, is we can go into the Material Editor, and in the luminance channel
is where the image is loaded up.
And if I click on the image, we can actually up the exposure here
to brighten this up overall. And you'll see that our reflections will
be even brighter still. And we can even bring this a little darker.
So we'll remove some of those nice highlights,
add a little bit more contrast, and you can see we're seeing less
and less of the reflection. And this is really handy with something
like, you know, this cloudy scene. If I drag and drop that and double-click
on the cloudy scene, go into this little button that has our image, and adjust the
exposure here. So maybe we really brighten this up. And again, the benefit of having
a High Dynamic Range Image is it contains so much luminance information that we can
really get a lot of different details depending on the exposure level that we
have set here. So now you can see we got a lot more sky detail, but it's also blowing
out our scene. So you want to have a happy medium there where you're getting
enough of the details but you're not overexposing or blowing out a lot
of your reflections. Now, if you find there's a lot of distracting
reflections in your fishbowl, we can always go into our glass bowl
material, and go to the transparency and turn off these exit reflections.
Now, these exit reflections are turned on by default just because it's
physically accurate. But sometimes you'll see that without the exit reflections,
we actually have a much more pleasing image.
So, play around with that. If there's too much distracting reflections,
turn that exit reflections off and see what you get.
HDRIs are fairly easy to find across the web and for free,
so be sure to experiment with how each HDRI affects your objects and see which
one works best for the type of look that you're going for.