1 00:00:04,130 --> 00:00:10,460 ‫So the goal for this video is to have projectiles that actually launch through the air and behave as 2 00:00:10,460 --> 00:00:11,930 ‫projectiles should. 3 00:00:12,020 --> 00:00:13,520 ‫Hey, welcome back. 4 00:00:13,550 --> 00:00:19,430 ‫In this video, we're concerned with making our projectile actually behave like a projectile and move. 5 00:00:19,610 --> 00:00:22,040 ‫Now, there are different ways to handle this. 6 00:00:22,070 --> 00:00:28,220 ‫One way is to manually set the location and rotation of the projectile ourselves. 7 00:00:28,250 --> 00:00:33,680 ‫Now, this would generally require us to make the update every frame, so we would probably put this 8 00:00:33,680 --> 00:00:34,940 ‫in the tick function. 9 00:00:35,210 --> 00:00:41,810 ‫Another way is to simply add an impulse to the projectile and let the physics engine take over. 10 00:00:41,900 --> 00:00:48,440 ‫Essentially, we're applying a force and launching that projectile and letting gravity do its thing, 11 00:00:48,440 --> 00:00:51,380 ‫and the projectile will just fly off into the air. 12 00:00:51,410 --> 00:00:55,310 ‫Now, another way would be to use a movement component. 13 00:00:55,340 --> 00:01:00,560 ‫Now, this is a special type of component that we would add to our projectile class. 14 00:01:00,560 --> 00:01:06,230 ‫And after setting some parameters on the movement component, the movement component will handle the 15 00:01:06,230 --> 00:01:08,060 ‫movement for the actor. 16 00:01:08,090 --> 00:01:15,860 ‫Now it just so happens that Unreal Engine has a built in type of component made specifically for projectiles. 17 00:01:15,860 --> 00:01:20,210 ‫So this takes advantage of some of the built in features of Unreal Engine. 18 00:01:20,210 --> 00:01:26,120 ‫And by doing this, we allow the movement component to handle the movement for us based on the settings 19 00:01:26,120 --> 00:01:27,020 ‫that we provide. 20 00:01:27,020 --> 00:01:29,360 ‫So this is the method that we're going to use. 21 00:01:29,360 --> 00:01:35,750 ‫So we'd like to add a projectile movement component to our projectile class, and this is what will 22 00:01:35,750 --> 00:01:38,690 ‫handle the movement for the projectile object. 23 00:01:38,690 --> 00:01:45,440 ‫So as we spawn a projectile in the world, the projectile movement component which belongs to the projectile 24 00:01:45,440 --> 00:01:51,620 ‫class, can be set up and customized based on the variables on the projectile movement class that we 25 00:01:51,650 --> 00:01:52,190 ‫set. 26 00:01:52,220 --> 00:01:58,340 ‫Now we're going to set a couple of those, such as its initial speed and its max speed and the projectile 27 00:01:58,340 --> 00:02:02,750 ‫movement component will actually move the projectile in the world for us. 28 00:02:02,780 --> 00:02:06,290 ‫Now, here's the Unreal Engine Documentation page for you. 29 00:02:06,290 --> 00:02:07,940 ‫Projectile movement component. 30 00:02:07,940 --> 00:02:13,130 ‫This is the component that we're concerned with and you'll see that it says Projectile Movement Component 31 00:02:13,130 --> 00:02:16,700 ‫updates the position of another component during its tick. 32 00:02:16,700 --> 00:02:19,340 ‫By default, it's going to move the route component. 33 00:02:19,370 --> 00:02:20,900 ‫Now here's the include. 34 00:02:20,900 --> 00:02:26,060 ‫And if you continue scrolling down, you'll see some of the variables that can be set on the movement 35 00:02:26,060 --> 00:02:26,810 ‫component. 36 00:02:26,810 --> 00:02:30,740 ‫So scroll through this and take a look and see what the options are. 37 00:02:30,770 --> 00:02:36,770 ‫Now we add a projectile movement component to our class the same way we would add any other component, 38 00:02:36,770 --> 00:02:39,350 ‫which means you already know how to do this. 39 00:02:39,350 --> 00:02:45,980 ‫So your challenge is to go into the projectile class and add a you projectile movement component pointer 40 00:02:45,980 --> 00:02:49,310 ‫variable and expose this by making it visible anywhere. 41 00:02:49,310 --> 00:02:54,140 ‫And that way we can easily edit the projectile movement component from within blueprints. 42 00:02:54,150 --> 00:02:59,560 ‫Now you're going to construct it in the projectile constructor using create default sub object. 43 00:02:59,570 --> 00:03:05,900 ‫Don't forget to include the proper header and set the initial speed and max speed variables of the projectile 44 00:03:05,900 --> 00:03:06,920 ‫movement component. 45 00:03:06,920 --> 00:03:12,650 ‫Now choose your own values for these and set them in the constructor and then playtest the game. 46 00:03:12,650 --> 00:03:18,530 ‫You're going to adjust initial speed and max speed in the details panel by selecting the component in 47 00:03:18,530 --> 00:03:19,790 ‫the projectile blueprint. 48 00:03:19,790 --> 00:03:25,910 ‫And this will give you a little bit of experience tweaking parameters and experimenting as a developer. 49 00:03:25,910 --> 00:03:30,080 ‫So pause the video and create the projectile movement component now. 50 00:03:32,900 --> 00:03:33,180 ‫Okay. 51 00:03:33,230 --> 00:03:39,380 ‫So I'm here in projectile H and you probably added your component in the private section. 52 00:03:39,380 --> 00:03:41,780 ‫So if you did, you have the right instincts. 53 00:03:41,780 --> 00:03:43,730 ‫We're going to make this a private variable. 54 00:03:43,730 --> 00:03:44,180 ‫That's okay. 55 00:03:44,180 --> 00:03:48,040 ‫If you didn't, you can easily move it to the private section if you wish. 56 00:03:48,050 --> 00:03:54,560 ‫Now, this will be a U projectile movement component, and that's a pointer. 57 00:03:54,560 --> 00:03:58,610 ‫And we can simply call this projectile movement component. 58 00:03:58,760 --> 00:04:05,300 ‫Now, I'm going to give this a U property and simply make this visible anywhere. 59 00:04:06,020 --> 00:04:08,210 ‫Now, you probably gave it a category. 60 00:04:08,210 --> 00:04:13,130 ‫If not, that's totally fine, but I'm going to give it a category and call it movement. 61 00:04:13,130 --> 00:04:15,650 ‫So we have the projectile movement component. 62 00:04:15,650 --> 00:04:20,660 ‫I'm going to leave off the forward declaration and see if I can get away with compiling now here in 63 00:04:20,660 --> 00:04:24,290 ‫projectile CP, I'm going to include the header file. 64 00:04:24,290 --> 00:04:31,340 ‫So back to the documentation page, I'm going to copy this include and simply paste it in here in projectile. 65 00:04:31,340 --> 00:04:34,250 ‫And now I'm ready to construct my component. 66 00:04:34,250 --> 00:04:42,440 ‫So I'm going to say projectile movement component and I'm going to use create default sub object and 67 00:04:42,440 --> 00:04:48,140 ‫the type will be you projectile movement component. 68 00:04:48,470 --> 00:04:55,760 ‫And for the text, I'm simply going to call this projectile movement component just like that. 69 00:04:55,760 --> 00:04:59,300 ‫There's my semicolon and there we have it. 70 00:04:59,330 --> 00:05:07,850 ‫Now as instructed we're going to set projectile movement, component max speed, and I'm going to give 71 00:05:07,850 --> 00:05:14,810 ‫this an initial speed of, say, 1300 F This is something that we will experiment with and through play 72 00:05:14,810 --> 00:05:17,600 ‫testing will adjust this to the right value. 73 00:05:17,600 --> 00:05:25,490 ‫Now I'm going to set projectile movement component initial speed, and I'll set it to the same value. 74 00:05:25,910 --> 00:05:31,190 ‫So initial speed is going to be how fast the projectile component is when it starts. 75 00:05:31,190 --> 00:05:33,710 ‫And of course, it'll never go over max speed. 76 00:05:33,860 --> 00:05:35,750 ‫Let's go ahead and compile this. 77 00:05:36,050 --> 00:05:42,200 ‫Okay, so I'm getting a compilation error and if I go up I'll see that it's referencing projectile h. 78 00:05:42,350 --> 00:05:47,240 ‫So let's go back to projectile H and it says Projectile H 27. 79 00:05:47,240 --> 00:05:51,020 ‫It's referring to line 27 and that's this line right here. 80 00:05:51,140 --> 00:05:56,090 ‫And we get this projectile movement component is not a member of a projectile. 81 00:05:56,120 --> 00:05:59,990 ‫Remember, this was the type of error we saw when we didn't forward declare. 82 00:05:59,990 --> 00:06:06,590 ‫So we can easily forward declare this with the class keyword and compile again and we get a successful 83 00:06:06,590 --> 00:06:07,400 ‫compile. 84 00:06:07,400 --> 00:06:12,830 ‫So again, this is how we can learn whether or not a particular component is included by default. 85 00:06:12,830 --> 00:06:17,270 ‫And we saw that this one is not so with a successful compile. 86 00:06:17,270 --> 00:06:18,890 ‫Let's hop back in the editor. 87 00:06:19,280 --> 00:06:26,030 ‫Okay, so I'm back in the editor and I'm going to go into blueprints and actors and here is BFP projectile. 88 00:06:26,300 --> 00:06:28,190 ‫So here NP projectile. 89 00:06:28,190 --> 00:06:32,090 ‫Now I see that projectile movement component is here. 90 00:06:32,390 --> 00:06:38,870 ‫And in the details panel, you can see under projectile we have initial speed and max speed and you 91 00:06:38,870 --> 00:06:43,280 ‫can scroll through and see a lot of other parameters that we can set as well. 92 00:06:43,400 --> 00:06:44,840 ‫So let's play test this. 93 00:06:44,840 --> 00:06:49,190 ‫I'm going to hit play and left click and check it out. 94 00:06:49,190 --> 00:06:51,200 ‫Our projectiles are moving. 95 00:06:51,200 --> 00:06:55,550 ‫They are flying through the air and they stop once they actually hit something. 96 00:06:55,550 --> 00:07:00,260 ‫Now, eventually what we'd like to do is have them blow up and cause damage. 97 00:07:00,260 --> 00:07:02,780 ‫But this is a great starting point. 98 00:07:02,780 --> 00:07:08,420 ‫Now let's move within fire range and see if the turrets will spawn a projectile. 99 00:07:08,420 --> 00:07:09,740 ‫And of course they don't. 100 00:07:09,740 --> 00:07:13,640 ‫And the reason is because we have that TW subclass of variable. 101 00:07:13,640 --> 00:07:19,310 ‫So if you're wondering why the turrets weren't actually spawning projectiles, you may not have set 102 00:07:19,310 --> 00:07:19,730 ‫that. 103 00:07:19,730 --> 00:07:25,370 ‫So let's go ahead and go into ponds and beep pond, turret and open full blueprint. 104 00:07:25,370 --> 00:07:29,960 ‫Editor And we placed the projectile class in the combat section. 105 00:07:29,960 --> 00:07:37,790 ‫This is our subclass of so if we set this to BP projectile now our turret should start spawning projectiles 106 00:07:37,790 --> 00:07:38,780 ‫as well. 107 00:07:38,780 --> 00:07:41,960 ‫So let's get in fire range and there we have it. 108 00:07:41,960 --> 00:07:43,910 ‫It's shooting projectiles at us. 109 00:07:43,910 --> 00:07:46,550 ‫So this is looking awesome. 110 00:07:47,030 --> 00:07:48,950 ‫So we now have projectiles. 111 00:07:48,950 --> 00:07:51,230 ‫So let's take a look at our section plan. 112 00:07:51,230 --> 00:07:56,900 ‫We've already created a tank that can move throughout the world and we're now handling input with the 113 00:07:56,900 --> 00:07:59,150 ‫WASD keys and mouse clicks. 114 00:07:59,150 --> 00:08:05,510 ‫We've created an enemy turret class, we called it tower in C++ and we've added fire functionality with 115 00:08:05,510 --> 00:08:06,590 ‫projectiles. 116 00:08:06,590 --> 00:08:11,240 ‫Now next, we need to handle health damage and destruction in this game. 117 00:08:11,240 --> 00:08:15,770 ‫So those are our next steps and those are coming up in the videos to come. 118 00:08:15,770 --> 00:08:21,890 ‫So now that we've added a projectile movement component, we now have actual projectiles. 119 00:08:21,890 --> 00:08:26,990 ‫I'll see you in the next video when we start to talk about how we can make these projectiles actually 120 00:08:26,990 --> 00:08:29,270 ‫blow up and cause damage. 121 00:08:29,690 --> 00:08:30,650 ‫I'll see you soon.