1 00:00:03,130 --> 00:00:07,960 In this lecture, we're finishing off our functionality so that if I reach my red finishing line or 2 00:00:07,960 --> 00:00:13,360 if I have a crash bonk and bump my head, I reload the scene and take the player right back to the start 3 00:00:13,360 --> 00:00:14,230 of where we started. 4 00:00:14,230 --> 00:00:17,890 This is me crossing the finishing line and that also reloads our scene. 5 00:00:17,890 --> 00:00:22,630 We're going to be talking about namespaces, having a bit of a conversation about the scene manager 6 00:00:22,630 --> 00:00:24,160 class in unity. 7 00:00:24,160 --> 00:00:25,300 Let's get started to best. 8 00:00:25,300 --> 00:00:26,110 Describe what we're doing. 9 00:00:26,110 --> 00:00:29,770 I've got a little bit of theory for us to work through here, so I'm going to talk about organizing 10 00:00:29,770 --> 00:00:30,370 our code. 11 00:00:30,370 --> 00:00:35,500 And the important thing to know is that the more code we have, the higher likelihood of conflicts between 12 00:00:35,500 --> 00:00:40,150 the names and the behaviors that we're creating, especially if you're working on a multi person project. 13 00:00:40,150 --> 00:00:46,300 So for example, programmer, one might be working on the player and they're using movement method, 14 00:00:46,300 --> 00:00:50,080 but player two is working on enemy and also uses movement methods. 15 00:00:50,080 --> 00:00:56,170 So you can have this conflict of naming if you don't have things separated properly so that the movement 16 00:00:56,170 --> 00:01:03,100 in the player class or the player script or wherever programmer one is working on player can't actually 17 00:01:03,100 --> 00:01:08,560 impact or communicate with or know about the movement method that Programmer two is working on. 18 00:01:08,560 --> 00:01:13,420 So in C sharp, our code is grouped with a particular structure to reduce conflicts. 19 00:01:13,420 --> 00:01:16,000 And let me show you how this is broadly organized. 20 00:01:16,000 --> 00:01:19,720 It's kind of like a Russian doll where things stack inside other things. 21 00:01:19,720 --> 00:01:22,930 So we have statements and these are within methods. 22 00:01:22,930 --> 00:01:26,380 So the methods is where we're saying, do this particular thing. 23 00:01:26,380 --> 00:01:31,600 We've done a bunch of these in our code so far, making our methods and also calling methods that unity 24 00:01:31,600 --> 00:01:33,220 has created for us. 25 00:01:33,220 --> 00:01:38,800 Add talk, for example, is a method that adds talk to our object and has it spin, and then methods 26 00:01:38,800 --> 00:01:40,930 are contained within classes. 27 00:01:40,930 --> 00:01:49,150 Or saying this another way Classes are a way to group methods and statements and variables into logical 28 00:01:49,150 --> 00:01:49,930 grouping. 29 00:01:49,930 --> 00:01:55,720 So we put all of that into a particular class and you can see we so far in our project right now we 30 00:01:55,720 --> 00:02:00,730 have a crash detector class, a finish line class and a player controller class. 31 00:02:00,730 --> 00:02:03,790 And usually we have one class per script. 32 00:02:03,790 --> 00:02:05,710 You don't have to you can have multiple classes. 33 00:02:05,710 --> 00:02:09,580 You see here we've got the keyword class and this class is called crash detector. 34 00:02:09,580 --> 00:02:13,330 And over in finish line we have the keyword class and this is called finish line. 35 00:02:13,330 --> 00:02:14,560 So this is the class. 36 00:02:14,560 --> 00:02:18,910 And grouped within that we have our methods and statements and all that kind of stuff. 37 00:02:18,910 --> 00:02:26,410 And so this is us making our own classes, we're making brand new classes, whereas when we call a method 38 00:02:26,410 --> 00:02:31,930 that's already within unity, we're tapping into Unity's classes which are in the big library of classes 39 00:02:31,930 --> 00:02:33,310 that we've got access to. 40 00:02:33,310 --> 00:02:36,460 So this is us making our own, but we can also use the unity ones. 41 00:02:36,460 --> 00:02:39,850 And then classes are grouped in namespaces. 42 00:02:39,850 --> 00:02:44,080 Namespaces will have a bunch of classes, classes have a bunch of methods and so on. 43 00:02:44,080 --> 00:02:49,480 And so if we have a look in here, the using is the keyword that we use to say that it's a particular 44 00:02:49,480 --> 00:02:50,110 namespace. 45 00:02:50,110 --> 00:02:54,820 So a lot of the code we're using is just within the general unity engine namespace. 46 00:02:54,820 --> 00:02:59,140 So if I was to go and comment out using Unity Engine, what would happen in here? 47 00:02:59,140 --> 00:03:00,430 Would we have any conflicts? 48 00:03:00,430 --> 00:03:00,940 Okay. 49 00:03:00,940 --> 00:03:04,720 So mono behavior collider to DX debug. 50 00:03:04,720 --> 00:03:08,890 These are the some of the things that are included within this unity engine namespace. 51 00:03:08,890 --> 00:03:10,330 So we'll take that away. 52 00:03:10,330 --> 00:03:15,040 Or as you can see, these two up at the top are grayed out and then ones that when we make a script, 53 00:03:15,040 --> 00:03:18,760 it just pops them in there saying, Hey, we think you might want to use these, but we don't actually 54 00:03:18,760 --> 00:03:19,120 use them. 55 00:03:19,120 --> 00:03:21,370 So we could delete them if we wanted to. 56 00:03:21,370 --> 00:03:22,510 I'm going to leave them there for now. 57 00:03:22,510 --> 00:03:24,010 Just something we tend to forget about. 58 00:03:24,010 --> 00:03:25,390 They're just there because they're there. 59 00:03:25,390 --> 00:03:30,610 But if we wanted to go and use functionality, that's from a namespace that we don't have here just 60 00:03:30,610 --> 00:03:32,560 yet, we need to use using. 61 00:03:32,560 --> 00:03:35,170 So I'm going to do this within my finish line script. 62 00:03:35,170 --> 00:03:44,050 I'm going to add in using Unity Engine Dot and you can see here's a whole bunch of things that we can 63 00:03:44,050 --> 00:03:45,190 get access to in here. 64 00:03:45,190 --> 00:03:50,950 But I'm looking for scene management and why not just write out using all of the namespaces? 65 00:03:50,950 --> 00:03:55,210 So using this, using that, using that, using that, well, it makes our code very messy and unreadable. 66 00:03:55,210 --> 00:03:59,830 If we come in here and we see that there's using unity engine like, okay, most things use unity engine 67 00:03:59,830 --> 00:04:01,540 call using scene management. 68 00:04:01,540 --> 00:04:03,790 Okay, this relates to scene management. 69 00:04:03,790 --> 00:04:08,500 We're not wading through 18 or 100 or 200 different namespaces in here. 70 00:04:08,500 --> 00:04:14,350 So the philosophy is we only use what we need to and we only tell our code to look at what we want it 71 00:04:14,350 --> 00:04:15,010 to look at. 72 00:04:15,010 --> 00:04:15,370 Okay. 73 00:04:15,370 --> 00:04:16,720 So we're looking at scene management. 74 00:04:16,720 --> 00:04:17,709 What can we do in here? 75 00:04:17,709 --> 00:04:26,500 Well, instead of debug log, we now have access to if I type in scene manager, this is a class that 76 00:04:26,500 --> 00:04:28,780 is within the scene management namespace. 77 00:04:28,780 --> 00:04:35,050 So the scene management manager, class dot and the dot operator allows us to tap into the methods that 78 00:04:35,050 --> 00:04:36,400 are within this class. 79 00:04:36,400 --> 00:04:42,370 And in here I'm going to look for the load scene method and load scene does what you think it will do 80 00:04:42,370 --> 00:04:43,420 at loads a scene. 81 00:04:43,420 --> 00:04:48,220 I'm going to add my parentheses in here and semicolon and I'm going to get to that in a moment. 82 00:04:48,220 --> 00:04:50,680 We've got the squiggly line because it says, oh, I don't know what you want to load. 83 00:04:50,680 --> 00:04:51,880 We'll get to that in just a second. 84 00:04:51,880 --> 00:04:56,800 But I want what I want to show you is the documentation in Unity on scene manager. 85 00:04:56,800 --> 00:05:02,080 So if you type in Unity Docs scene manager into your browser, I've also given you a link for this, 86 00:05:02,080 --> 00:05:02,230 but. 87 00:05:02,300 --> 00:05:06,680 Generally if you search for Unity Docs and then whatever it is you're interested in, you'll find pretty 88 00:05:06,680 --> 00:05:11,690 quickly the scripting API scene manager dash unity and this will give us some extra information. 89 00:05:11,690 --> 00:05:15,470 So within here, the scene manager, we haven't looked at this before, but this is quite important. 90 00:05:15,470 --> 00:05:16,940 There's lots of cool information in here. 91 00:05:16,940 --> 00:05:23,840 We can see that the scene manager class, which is in the Unity Scene Management namespace, you can 92 00:05:23,840 --> 00:05:29,150 see that it has some static properties that's is seen manager class has some static methods and it has 93 00:05:29,150 --> 00:05:29,810 some events. 94 00:05:29,810 --> 00:05:33,740 So you don't need to know exactly the difference between static and not static and what events are. 95 00:05:33,740 --> 00:05:37,520 But you can see that we've got some methods in here that we can access and use. 96 00:05:37,520 --> 00:05:42,650 So we can use load scene, we can use merge scenes, we can use create scene or get active scene. 97 00:05:42,650 --> 00:05:44,810 So these are the things that are built in already. 98 00:05:44,810 --> 00:05:49,430 So if you're wondering how do we know the list of stuff when you go to the Unity Docs and you can see 99 00:05:49,430 --> 00:05:55,130 in classes within the Unity Scene management, we've got a few different classes within this particular 100 00:05:55,130 --> 00:05:55,490 class. 101 00:05:55,490 --> 00:05:57,650 We've got a bunch of different methods. 102 00:05:57,650 --> 00:06:02,510 So I just want to show you that Unity has got great documentation for when you start to get more comfortable 103 00:06:02,510 --> 00:06:05,330 and you want when you want to dig into these particular things. 104 00:06:05,330 --> 00:06:08,600 And if we click on Load Scene, what does it tell us in here gives us some information. 105 00:06:08,600 --> 00:06:14,990 It shows us that we need the scene name or the scene build index and it gives us a little bit of a description 106 00:06:14,990 --> 00:06:15,740 of what we're doing. 107 00:06:15,740 --> 00:06:17,990 And then it's going to give us some example code. 108 00:06:17,990 --> 00:06:22,220 So often when you get stuck, you can come in to here and you can find some clues about what's going 109 00:06:22,220 --> 00:06:22,580 on. 110 00:06:22,580 --> 00:06:24,950 But what I know we need to do back into unity. 111 00:06:24,950 --> 00:06:30,770 We need to jump up to file and go to build settings because we need to identify that our scene is a 112 00:06:30,770 --> 00:06:31,730 particular scene. 113 00:06:31,730 --> 00:06:35,300 And just to make this even clearer, what I'm going to do is rename my scene. 114 00:06:35,300 --> 00:06:38,360 If we're going to our scenes folder here, you can see it's called sample scene. 115 00:06:38,390 --> 00:06:44,990 It's going to go to file save as I'm going to save this scene in the scenes folder as just say level 116 00:06:44,990 --> 00:06:48,440 one because we've only got one level, we'll probably only have one level for this game, but we'll 117 00:06:48,440 --> 00:06:49,280 call it level one. 118 00:06:49,280 --> 00:06:52,730 Now you see we've got level one and sample scene and they are exactly the same. 119 00:06:52,730 --> 00:06:56,480 So because of that I'm going to delete sample scene, delete, don't need it anymore. 120 00:06:56,480 --> 00:06:58,020 Level one is exactly the same. 121 00:06:58,070 --> 00:07:04,190 So I did a save as and now when I jump up to file build settings you'll see that sample scene has been 122 00:07:04,190 --> 00:07:04,670 deleted. 123 00:07:04,670 --> 00:07:05,120 That's cool. 124 00:07:05,120 --> 00:07:08,540 I wanted to get some change in here, so I'm going to highlight that hit delete. 125 00:07:08,540 --> 00:07:09,530 So it's cleaned up. 126 00:07:09,530 --> 00:07:14,390 Now what I need to do is add open scenes and it will put in my level one. 127 00:07:14,390 --> 00:07:17,540 So that's the process for adding a new scene into build index. 128 00:07:17,540 --> 00:07:22,550 And if you go and make a whole bunch of scenes in here and you don't add them within your build settings, 129 00:07:22,550 --> 00:07:27,590 then Unity won't know about them and won't include them within your game and won't allow the scene manager 130 00:07:27,590 --> 00:07:29,210 to load between them. 131 00:07:29,210 --> 00:07:35,060 So now that we know this is level one, so we know the name is Level one and we know the index all the 132 00:07:35,060 --> 00:07:38,030 way over here is zero and is often the case with programming. 133 00:07:38,030 --> 00:07:40,220 We start at zero and then we go to one and two and three. 134 00:07:40,220 --> 00:07:42,560 So this is scene index zero. 135 00:07:42,560 --> 00:07:47,120 If I jump back over into load scene, we can either put in here the name or we can put in the index. 136 00:07:47,120 --> 00:07:48,560 For now, I'm just going to add zero. 137 00:07:48,560 --> 00:07:51,980 That's the index for this one and only scene we have in our game. 138 00:07:51,980 --> 00:07:55,940 So when the player goes through the finishing line, we are going to load scene zero. 139 00:07:55,970 --> 00:07:58,970 Let's save on that and see if we've got our functionality correct. 140 00:07:58,970 --> 00:08:00,830 It's going to close down the build settings. 141 00:08:00,830 --> 00:08:04,510 We don't need to do anything more in here, but in the future this is where we would build so we can 142 00:08:04,520 --> 00:08:05,780 make a WebGL build. 143 00:08:05,780 --> 00:08:09,980 For example, I'm going to click on play and that was the finish line I was working on. 144 00:08:09,980 --> 00:08:13,910 So when we scroll down here, it puts me all the way back to the start. 145 00:08:13,910 --> 00:08:16,250 So I use reloading the whole scene. 146 00:08:16,250 --> 00:08:21,200 It's the equivalent of me pushing play is what's going on there, because our code is saying, just 147 00:08:21,200 --> 00:08:23,360 reload the scene and we don't have a delay. 148 00:08:23,360 --> 00:08:25,220 There's a little bit of fanciness we can do around this. 149 00:08:25,250 --> 00:08:25,910 We'll do later on. 150 00:08:25,910 --> 00:08:31,250 But now this is doing exactly what we wanted it to, which is just reloading the exact same scene, 151 00:08:31,250 --> 00:08:32,900 putting us back to the start of the level. 152 00:08:32,900 --> 00:08:34,100 So I have a challenge for you. 153 00:08:34,100 --> 00:08:35,539 You've probably guess what it is already. 154 00:08:35,539 --> 00:08:40,970 It's to reload our scene when we bump into the ground to finish the crash detector script that you're 155 00:08:40,970 --> 00:08:42,500 working on in the last lecture. 156 00:08:42,500 --> 00:08:45,380 So pause the video and implement that functionality. 157 00:08:47,390 --> 00:08:47,780 Okay. 158 00:08:47,780 --> 00:08:49,100 Let's find the one we're looking for. 159 00:08:49,100 --> 00:08:53,120 We're looking for crash detector in here instead of debug log out. 160 00:08:53,120 --> 00:08:53,930 I hit my head. 161 00:08:53,930 --> 00:09:00,320 I'm going to use the same code scene manager and you can see as I type it in it doesn't know what I'm 162 00:09:00,320 --> 00:09:05,870 trying to do squiggly line it's not auto completing that's because we're not using the unity engine 163 00:09:06,170 --> 00:09:12,350 scene management little trick for you here if you type in scene manager this is we you and I know this 164 00:09:12,350 --> 00:09:15,230 is from the scene management namespace. 165 00:09:15,230 --> 00:09:21,560 If I hit control and period or full stop on the keyboard, it gives me some options in here and it gives 166 00:09:21,560 --> 00:09:27,080 me the option of adding to our script using unity engine scene management. 167 00:09:27,080 --> 00:09:32,780 So I can just click on that and it will automatically add in the namespace that's relevant for the thing 168 00:09:32,780 --> 00:09:35,150 I'm typing in, so that's a quick way of doing it. 169 00:09:35,150 --> 00:09:38,510 Or you could have just typed out the whole using statement at the top here. 170 00:09:38,600 --> 00:09:47,540 Okay, scene manager load scene and it's going to be build index zero once again save with our semicolon 171 00:09:47,540 --> 00:09:49,910 at the end, click on play. 172 00:09:50,180 --> 00:09:50,870 Actually, you know what? 173 00:09:50,870 --> 00:09:55,280 I'm going to move my finish line a little bit further away just so we don't crash into it before I've 174 00:09:55,280 --> 00:09:57,800 had a chance to crash into the ground bump down there. 175 00:09:59,210 --> 00:10:02,090 And we will get rolling. 176 00:10:02,090 --> 00:10:06,710 And then if I flip upside down and we reload the scene. 177 00:10:06,740 --> 00:10:07,370 Boink. 178 00:10:07,670 --> 00:10:08,580 Excellent point. 179 00:10:08,600 --> 00:10:09,560 So we've got that working. 180 00:10:09,560 --> 00:10:11,360 We've got our win condition. 181 00:10:11,360 --> 00:10:17,060 If we make it all the way down to our red thingamajig, be our finishing line, then we'll reload the 182 00:10:17,060 --> 00:10:17,330 scene. 183 00:10:17,330 --> 00:10:23,330 And also, if we bonk our head, we reload the scene using the scene manager class, which is contained 184 00:10:23,330 --> 00:10:26,030 within the scene management namespace. 185 00:10:26,060 --> 00:10:26,660 Great work. 186 00:10:26,660 --> 00:10:27,740 I'll see you in the next lecture.