[flow_default] Transcription: 005 Lumen and the basics of lighting.json

transcriptions/005 Lumen and the basics of lighting.json

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+{
+  "audio_file": "005 Lumen and the basics of lighting.wav",
+  "text": "Alright guys, let's talk about global illumination and lumen Unreal Engine 5's new global illumination system that is ready to change how we develop games. So to start, what is global illumination? Well, global illumination is essentially simulating how light actually bounces around in your scene accurately or at least more accurately than it was simulated before. So what do I mean? Let's take a look at this scene. Now you can see there's a light in the center and two different objects. And the light is clearly being simulated. I mean, it looks like there's a light and we can see these objects. However, if you'll notice, the shadow is completely dark. And what that essentially means is that the game engine is saying, all right, the light is coming from here and hitting this object. And it's reflecting there. And it's coming into the viewport, or your eyes, right? So you can actually see the scene. But what isn't happening is that light isn't bouncing around and diffusing like real light does. You know, if this was a real, real light in a real scene, you'd be able to see in this corner because light would bounce off this wall and then off that wall and then back over here. It diffuses because the light's making many, many more bounces and reflections than this basic system can simulate. So what Lumen does is using a mixture of ray tracing and other lighting techniques, it is able to accurately or at least accurately enough simulate that process and give us a much more realistic lighting experience in real time. And that's the key part. The fact that you can do this without having to bake or build or render your lighting and global illumination is incredible and it's going to change the types of scenes you can build and it's going to optimize your game development workflows. So, moment of truth. If this is the old system, what does the new system look like? Well, luckily, I have created this box here with global illumination. I'll explain to you in a minute how I did that. But as you can see in this one, automatically you can tell you can see what's going on in the shadow. There's indirect light. And if I look closer or if I move the object, you can see that it's also reflecting the color of video game or the Matrix. Here, it's much, much harder to tell. So that is what Lumen is and why it's so important. And another important thing to note is that while in previous game engines you could get an effect like this it was only with static lighting scenes so if I was to move this I'd have to rebuild the lighting of my scene completely every single time that's why lumen is so powerful and that's why Unreal 5 is so powerful and it even works with things like emissive materials and objects, which wasn't even possible with hardware ray tracing on older game engines such as Unreal 4. Look at how good looking that is. It's beautiful. Now, of course, this system doesn't come without its problems. And it certainly isn't capable of accurately simulating light. And we can see here, created a reflective surface that while it does reflect the objects pretty well, it's got some problems. And that's to be expected. Unreal Engine is still in early access at the moment that this tutorial is going to be released. But at the end of the day, this is still an incredible system and it's still going to change the way we develop games. All right, now I'm gonna go over some of the basics of lighting, different types of games. All right, now I'm going to go over some of the basics of lighting, different types of lights, and how you can use them to your advantage. So let me grab this point light. Oh, and actually, before I get into this, I do want to say, where do my point let go? Let me pull it out. Thank you. I do wanna say that the way I changed the settings from Lumen to the old settings and vice versa, was I created this thing called a post-process volume, which you can grab from visual effects. And this allows you to change the lighting settings within the space or the boundary of the volume. So if I go to this first post-processed volume and I go down here in the details panel, I can see that under global illumination, I have lumens set. Oh, excuse me, I have Method None. So no global illumination. Old deprecated ray tracing. I can actually change that to Lumen. I'm going beautiful. Anyway, we're gonna go back to there. All right, so let's go over some different types of lights. So this is a point light, as you can see. Just simply like a light bulb that's hanging in the room. Now I can delete that and I'm going to create a spotlight. This is also fairly self-explanatory. Basically just a spotlight. I can lift it up and I can even go to change the radius of the cone. Now it's just basically a light. I have all sorts of different settings that I can edit in the details panel on the right. So I can create, change the source radius. This will actually make it so your shadows look softer. If you look right there, right here, right here, you can see how it gets softer as I change that source radius. Intercone angle, so you can have multiple cones. Indirect light at lighting volume, so that's the quantity of indirect lighting. All sorts of things. Now it's also important to note that if I go back and add a point light in, I can change the settings on this as well. And I even have some cool ones like use temperature, so I can change the temperature light color as well. Now I can do this on all different lights, but I want to demonstrate with the point light. Just to make sure that you know that you can to return to the defaults Okay, awesome now next light is going to be a rectangle light That's the room Boom and as you can see just a rectangular light light you would imagine. Not a whole lot of rocket science going on here. Now you can change the barn door shutters and what by that if you see here in this little box there these little flaps. I can change the angle close it as if I had a shade. Pretty cool. And then finally, we have the directional light, or the skylight, I should say. Now, the skylight and directional light actually go together quite nicely. So I'm gonna go with the directional light first. And the directional light is essentially the sun. You can move it around like this. And by changing its angle, oh, Unreal Engine, you are finicky today. You can change its direction. Now I can change it in this direction as well. And once again, the fact that I'm doing this in real time and the indirect lighting is computing the way it is is just incredible. I mean without something like Lumen a movable light like the Sun is much more difficult to get global illumination with. Or just imagine a torch moving through an environment or just simply editing and wanting to be able to move your objects around. I mean it's incredible. Now if we want this to actually act like a Sun we need to use it in tandem with the skylight. So I'm gonna go here, pull in a skylight, and nothing's gonna happen. And that's okay, because we need to do a little bit extra setup before this happens. Now, a skylight is essentially just almost an image of sorts that's being projected on the outside of your world. Sky Atmosphere And this will give us realistic sky effects like clouds and a sun. Now what we're gonna have to do is change some settings before any of this works together. We need to tell this directional light here that it should project onto these two images. So, go here, go down, down, down, down, atmosphere in cloud. Hit true. Hmm, all right, let me try again. Just delete these all. Create a directional light, drag it in. There's nothing else out here. Is there cool? Skylight. Sky atmosphere. Come down to atmosphere. I'm on the wrong button. Boom, there we go. And now we have our sky. Let's rotate this a bit, show it off. You can even see the sun over there. And this is infinite, so no matter where you are in this world, you will have the sun shining overhead if that's the direction it's pointing. I can also point it as if it's on the other side of the earth. Alright, well that wraps up our lighting tutorial.",
+  "language": "en",
+  "confidence": null,
+  "duration": 798.83
+}