Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated: 1 1 00:00:04,290 --> 00:00:07,340 In this video, we're implementing our damage systems so that blank, 2 2 00:00:07,340 --> 00:00:11,020 there we go, we can shoot projectiles that kill enemies that have health. 3 3 00:00:11,020 --> 00:00:12,560 And when they get to zero, they're destroyed. 4 4 00:00:12,560 --> 00:00:14,820 So, let's jump in and get started. 5 5 00:00:14,820 --> 00:00:17,272 Okay, let's start off by implementing some colliders. 6 6 00:00:17,272 --> 00:00:20,910 I'm gonna find my Zucchini and add a component, 7 7 00:00:20,910 --> 00:00:24,220 which will be a collider, box collider 2D. 8 8 00:00:24,220 --> 00:00:25,010 I think that's pretty good. 9 9 00:00:25,010 --> 00:00:26,590 It doesn't need to be perfect with the Zucchini. 10 10 00:00:26,590 --> 00:00:29,020 I'll edit just a little bit, bring it in. 11 11 00:00:29,020 --> 00:00:32,270 Bring it down, bring it in just so it's reasonably tight. 12 12 00:00:33,670 --> 00:00:34,920 Click on the Edit Collider. 13 13 00:00:36,220 --> 00:00:36,850 Okay, there we go. 14 14 00:00:36,850 --> 00:00:38,882 Pretty good. It just kinda has to strike the center of 15 15 00:00:38,882 --> 00:00:39,530 the Zucchini. 16 16 00:00:39,530 --> 00:00:42,840 We're in lanes, so we don't need super precise collision. 17 17 00:00:42,840 --> 00:00:45,210 That's great, apply that back to the prefab, excellent. 18 18 00:00:45,210 --> 00:00:47,480 I think I can remove my Zucchini from the scene now. 19 19 00:00:47,480 --> 00:00:50,220 We'll just be using prefabs when we instantiate them. 20 20 00:00:50,220 --> 00:00:51,800 Now, let's find the lizard. 21 21 00:00:51,800 --> 00:00:54,130 The lizard, I do need to drag a lizard into the scene, so 22 22 00:00:54,130 --> 00:00:55,800 I can see what's going on. 23 23 00:00:55,800 --> 00:00:58,640 Click on ADD COMPONENT, Box Collider 2D. 24 24 00:00:58,640 --> 00:01:01,240 That's around the entire outside, which is a bit big. 25 25 00:01:01,240 --> 00:01:03,620 I'm gonna switch onto Lizard Walk. 26 26 00:01:03,620 --> 00:01:06,907 I think that's where I wanna have my collider around wherever he walks, because 27 27 00:01:06,907 --> 00:01:09,965 during the jump, I think the wizard should be little and even vulnerable. 28 28 00:01:09,965 --> 00:01:11,306 Jump, jump, jump, jump. 29 29 00:01:11,306 --> 00:01:16,520 Okay, during that stage, I don't really want my cactus to be hitting it. 30 30 00:01:16,520 --> 00:01:21,460 So I will just wrap my collider around, what it looks like when he's walking. 31 31 00:01:21,460 --> 00:01:24,603 So edit collider on the box, collider move this in. 32 32 00:01:24,603 --> 00:01:27,900 Move that in as well, move that down. 33 33 00:01:27,900 --> 00:01:30,250 Now move that whoops. 34 34 00:01:30,250 --> 00:01:32,480 That's bit of a pain when that happens. 35 35 00:01:32,480 --> 00:01:33,720 Back on Edit Collider. 36 36 00:01:34,860 --> 00:01:36,830 And there we go, excellent. 37 37 00:01:36,830 --> 00:01:39,350 Apply that back to the prefab. 38 38 00:01:39,350 --> 00:01:43,060 Very good, and once again, I don't think I need to my lizard any more. 39 39 00:01:43,060 --> 00:01:47,390 What I will do is find a Zucchini and find where we, 40 40 00:01:47,390 --> 00:01:49,370 is Trigger is on the Box Collider 2D. 41 41 00:01:49,370 --> 00:01:51,460 Is Trigger, tick that on. 42 42 00:01:51,460 --> 00:01:55,690 Now, one thing we need to review any time we're doing collisions, 43 43 00:01:55,690 --> 00:01:56,880 is our collision matrix. 44 44 00:01:56,880 --> 00:01:58,060 So let's have a quick look at that. 45 45 00:01:58,060 --> 00:02:00,080 We can see all of these grids in here. 46 46 00:02:00,080 --> 00:02:01,700 We've looked at these before. 47 47 00:02:01,700 --> 00:02:05,350 We're using a Trigger Static Trigger Collidor, 48 48 00:02:05,350 --> 00:02:09,460 Dynamic Rigidbody Trigger Collidor, Kinematic Rigidbody Trigger Collidor. 49 49 00:02:09,460 --> 00:02:12,420 Well it's not static and it's not dynamic, 50 50 00:02:12,420 --> 00:02:17,430 so it's gonna be a Kinematic Rigidbody Trigger Collidor which reminds me. 51 51 00:02:17,430 --> 00:02:19,410 We don't have a rigidbody anywhere. 52 52 00:02:19,410 --> 00:02:22,030 So I'll find my lizard. 53 53 00:02:23,100 --> 00:02:27,060 And add a rigidbody. 54 54 00:02:27,060 --> 00:02:28,580 I didn't list that out in my requirements. 55 55 00:02:28,580 --> 00:02:30,380 This is one of those things when you do the requirements, 56 56 00:02:30,380 --> 00:02:31,570 you think you're being pretty thorough. 57 57 00:02:31,570 --> 00:02:33,620 But we missed, that we need a rigidbody. 58 58 00:02:33,620 --> 00:02:37,250 I'll switch this to kinematic, cuz we're saying walk across the screen this way. 59 59 00:02:37,250 --> 00:02:40,390 I'm putting a rigidbody onto the lizard. 60 60 00:02:40,390 --> 00:02:43,840 And we could put a rigidbody on the projectile as well. 61 61 00:02:43,840 --> 00:02:47,184 Actually, let's do that just so we are being thorough on the Zucchini. 62 62 00:02:47,184 --> 00:02:49,836 Add Component, RigidBody 2D. 63 63 00:02:49,836 --> 00:02:53,350 And it's gonna work without this, I believe, but we'll say it's Kinematic. 64 64 00:02:53,350 --> 00:02:56,650 Now, temporary over into your scripts. 65 65 00:02:56,650 --> 00:02:57,810 What script are we looking for 66 66 00:02:57,810 --> 00:02:59,670 here as I move my microphone out of the way a little bit? 67 67 00:02:59,670 --> 00:03:01,660 I'm looking for the Projectile script. 68 68 00:03:01,660 --> 00:03:03,120 Open that up in Visual Studio. 69 69 00:03:04,620 --> 00:03:09,070 Let's start a new line, where we're going to check for the trigger. 70 70 00:03:09,070 --> 00:03:11,610 So we'll say void OnTriggerEnter2D, 71 71 00:03:11,610 --> 00:03:15,720 and the auto completes a bunch of stuff for us. 72 72 00:03:15,720 --> 00:03:17,960 I'm gonna rename from collision here, 73 73 00:03:17,960 --> 00:03:23,450 this is what's getting passed in, rename to this to otherCollider. 74 74 00:03:23,450 --> 00:03:25,150 otherCollision, we'll cal it otherCollider. 75 75 00:03:25,150 --> 00:03:26,610 You can call it whatever you want. 76 76 00:03:26,610 --> 00:03:28,470 You could call it bob if you wanted to, but 77 77 00:03:28,470 --> 00:03:33,450 I wanted to just be very clear that we're talking about the other things collider. 78 78 00:03:33,450 --> 00:03:38,060 So this is the projectile, and when we bump into anything else, 79 79 00:03:38,060 --> 00:03:41,330 we wanna know details about the anything else, so that's the otherCollider. 80 80 00:03:42,470 --> 00:03:45,756 No we haven't even done this for 81 81 00:03:45,756 --> 00:03:51,111 a while still be printing, so Debug .Log, 82 82 00:03:51,111 --> 00:03:57,830 and then ("I hit: " what do we hit + otherCollider-name). 83 83 00:03:57,830 --> 00:04:00,260 So we'll just make sure that our collision is working. 84 84 00:04:00,260 --> 00:04:03,763 Before we go anywhere else on collision, you always wanna make sure [LAUGH] it's 85 85 00:04:03,763 --> 00:04:06,320 working, or else you scratch your head wondering what's going on. 86 86 00:04:06,320 --> 00:04:08,340 So back over into here, click on Play. 87 87 00:04:10,150 --> 00:04:13,873 Once it's finished compiling and thinking, click on Play, open up the Console. 88 88 00:04:16,325 --> 00:04:19,599 A couple of warnings, we're not using that, that's fine. 89 89 00:04:19,599 --> 00:04:23,960 And then when this hits here, boing, we should get, I hit a lizard, excellent. 90 90 00:04:23,960 --> 00:04:26,470 Okay, so collision is successfully working. 91 91 00:04:26,470 --> 00:04:27,440 That's really important for 92 92 00:04:27,440 --> 00:04:30,450 us to be confident hat we're on top of that, good stuff. 93 93 00:04:31,570 --> 00:04:34,600 Okay, so when we have that collision moment, basically in here, 94 94 00:04:34,600 --> 00:04:37,910 what we wanna be doing is reduce health. 95 95 00:04:37,910 --> 00:04:39,220 That's what we wanna be doing in here. 96 96 00:04:39,220 --> 00:04:40,696 So how do we go about doing that? 97 97 00:04:40,696 --> 00:04:48,146 Well, we would call some sort of say, DealDamage method. 98 98 00:04:48,146 --> 00:04:49,631 And DealDamage(), we haven't created that yet, 99 99 00:04:49,631 --> 00:04:50,820 it doesn't know where it's coming from. 100 100 00:04:50,820 --> 00:04:53,200 So let's go and create all of that mechanism. 101 101 00:04:53,200 --> 00:04:56,660 So jump back over into Unity, we'll need to make ourselves a new script, 102 102 00:04:56,660 --> 00:04:58,180 which will be called Health. 103 103 00:04:58,180 --> 00:05:00,591 Create C# script, Health. 104 104 00:05:00,591 --> 00:05:03,380 I'll just double click on Health. 105 105 00:05:03,380 --> 00:05:06,110 Okay, so let's start off by giving ourselves a notion of how much health 106 106 00:05:06,110 --> 00:05:08,010 the particular thing will have. 107 107 00:05:08,010 --> 00:05:11,930 So SerializeField, and then this will be a float, 108 108 00:05:11,930 --> 00:05:16,700 we'll call this health, an issue like that 100f seems pretty good. 109 109 00:05:16,700 --> 00:05:18,480 Let's have a quick look at our checklist, 110 110 00:05:18,480 --> 00:05:20,580 we're going through the mechanism now the Health script. 111 111 00:05:20,580 --> 00:05:23,710 We've created Health script, serialize health, yes, create DealDamage, 112 112 00:05:23,710 --> 00:05:24,480 let's do that. 113 113 00:05:24,480 --> 00:05:28,920 So for now, I'm going to just get rid of start and update, 114 114 00:05:28,920 --> 00:05:32,790 we put them back in if we need them, create a public method, 115 115 00:05:32,790 --> 00:05:36,000 cuz we need to be accessing this from the projectile. 116 116 00:05:36,000 --> 00:05:39,890 The projectile's gonna say, I hit something, and we call the Deal Damage, so 117 117 00:05:39,890 --> 00:05:41,330 we call DealDamage. 118 118 00:05:42,630 --> 00:05:43,770 And what do we need at this point? 119 119 00:05:43,770 --> 00:05:47,020 Well we need to know how much damage to deal, 120 120 00:05:47,020 --> 00:05:50,740 and we want that to be dependent upon the particular projectile that's hit you. 121 121 00:05:50,740 --> 00:05:54,296 So we'll say, when DealDamage is called, 122 122 00:05:54,296 --> 00:05:59,387 we require you to let us know of type float how much damage it is, 123 123 00:05:59,387 --> 00:06:03,440 that you need to be passing back in to DealDamage. 124 124 00:06:03,440 --> 00:06:05,147 Okay, open our curly braces. 125 125 00:06:05,147 --> 00:06:09,310 And then within here we'll have 126 126 00:06:09,310 --> 00:06:14,110 the standard health -= damage;. 127 127 00:06:14,110 --> 00:06:16,310 So we're saying, whatever health you have at the moment starting up for 128 128 00:06:16,310 --> 00:06:21,540 the hundred is -= damage that's just being passed through when we call DealDamage. 129 129 00:06:21,540 --> 00:06:24,230 And then we do our standard if did. 130 130 00:06:24,230 --> 00:06:26,590 So if you think you know how to do this, 131 131 00:06:26,590 --> 00:06:32,080 then just if the health gets below zero, destroy the game object. 132 132 00:06:32,080 --> 00:06:32,772 Just complete that. 133 133 00:06:35,102 --> 00:06:38,611 Okay, if health is <0, 134 134 00:06:38,611 --> 00:06:44,360 then We will Destroy(gameObject). 135 135 00:06:44,360 --> 00:06:46,860 So basically destroying me is what that means. 136 136 00:06:46,860 --> 00:06:50,260 Whatever me is attached to, whatever this health has been placed onto. 137 137 00:06:50,260 --> 00:06:56,000 So it's been reasonably good, save that up, jump back over into projectile. 138 138 00:06:56,000 --> 00:06:59,880 Now, DealDamage, we have a mechanism for calling that. 139 139 00:06:59,880 --> 00:07:01,191 How are we gonna do that, 140 140 00:07:01,191 --> 00:07:04,381 well we know that when we collide with the particular thing. 141 141 00:07:04,381 --> 00:07:09,021 The otherCollider, then at that instance we know who the otherCollider belongs to. 142 142 00:07:09,021 --> 00:07:12,480 So we don't need to go searching through our entire project and say, 143 143 00:07:12,480 --> 00:07:16,054 hang on a minute who did I just collide with I just collided with the thing 144 144 00:07:16,054 --> 00:07:18,670 that owns the collider, so the otherCollider. 145 145 00:07:18,670 --> 00:07:21,990 This could be called otherObject that currently possesses a collider, but 146 146 00:07:21,990 --> 00:07:22,880 that's a bit too long. 147 147 00:07:22,880 --> 00:07:27,400 So, let's start of by creating a variable, which we'll call var, 148 148 00:07:27,400 --> 00:07:28,810 just a general variable. 149 149 00:07:28,810 --> 00:07:37,506 var health = otherColider.GetComponent. 150 150 00:07:37,506 --> 00:07:40,679 And component of type Health. 151 151 00:07:40,679 --> 00:07:43,867 Now we have a reference to the health component or the health script, so 152 152 00:07:43,867 --> 00:07:45,370 just remove my comments in here. 153 153 00:07:46,490 --> 00:07:49,842 Then DealDamage, instead of just DealDamage, we're going to say 154 154 00:07:49,842 --> 00:07:54,680 health.DealDamage, cuz we're referring to health which is our health component. 155 155 00:07:54,680 --> 00:07:57,315 And DealDamage, I spelled it incorrectly there. 156 156 00:07:57,315 --> 00:08:01,089 DealDamage, let me go back over into health and see what I code it. 157 157 00:08:01,089 --> 00:08:04,910 DealDamage, and the problem is that I'm not passing anything in. 158 158 00:08:04,910 --> 00:08:08,610 So it's saying we mass over it, it's saying there's no argument. 159 159 00:08:08,610 --> 00:08:12,079 And that was because we said we need to know how much damage, so 160 160 00:08:12,079 --> 00:08:14,900 thank you Visual Studio for reminding me of that. 161 161 00:08:14,900 --> 00:08:20,777 How much damage, well, let's say we need something a serialized damage. 162 162 00:08:20,777 --> 00:08:24,941 So we'll say damage in here, just kind of damage amount. 163 163 00:08:24,941 --> 00:08:30,675 Up at the time [SerializeField] float damage. 164 164 00:08:30,675 --> 00:08:36,268 Initialize that at, say, 50;. 165 165 00:08:36,268 --> 00:08:40,709 Okay, now it's happy, it's passing, it's calling, hey, DealDamage, I want you to 166 166 00:08:40,709 --> 00:08:45,160 give 50 points of damage, or whatever it's being changed to in the inspector. 167 167 00:08:45,160 --> 00:08:45,980 Now, let's jump over and 168 168 00:08:45,980 --> 00:08:50,142 see if we can get any mechanisms to see what's going on here. 169 169 00:08:50,142 --> 00:08:55,320 Go to Console, clear our issues, click on Play. 170 170 00:08:55,320 --> 00:08:57,260 Now, do we have a way to visualize what's going on? 171 171 00:08:57,260 --> 00:09:02,400 Let's find whichever the first lizard is that comes out. 172 172 00:09:02,400 --> 00:09:05,270 Let's grab them in our lane that is. 173 173 00:09:05,270 --> 00:09:08,580 So this guy just here if I can click on New, 174 174 00:09:08,580 --> 00:09:12,870 excellent, has health somewhere, we haven't added the health script. 175 175 00:09:14,110 --> 00:09:15,500 What are we crazy? 176 176 00:09:15,500 --> 00:09:17,780 That's what we are, we need to add the health script so 177 177 00:09:17,780 --> 00:09:20,770 find your prefab of the lizard. 178 178 00:09:20,770 --> 00:09:22,900 Click on Add Component, type in health. 179 179 00:09:24,410 --> 00:09:26,090 Double click on that, I'll single click on that. 180 180 00:09:26,090 --> 00:09:28,260 That is health, 100, yep that's fine. 181 181 00:09:28,260 --> 00:09:34,112 Now let we click on Play, I'm gonna select one of the attackers that spawns. 182 182 00:09:34,112 --> 00:09:37,300 This first, it was probably that guy, 183 183 00:09:37,300 --> 00:09:41,500 they have already hit him that one, yep, there we go. 184 184 00:09:41,500 --> 00:09:42,210 Already has 50 health. 185 185 00:09:42,210 --> 00:09:44,140 That first Zucchini smacked into it and 186 186 00:09:44,140 --> 00:09:46,780 then second time around, boom, health goes to 0. 187 187 00:09:46,780 --> 00:09:53,350 Excellent, so we have cactus shooting projectiles that's damaging the lizard. 188 188 00:09:53,350 --> 00:09:55,356 The lizard health is going down. 189 189 00:09:55,356 --> 00:09:58,281 We've done that by creating our own trigger, 190 190 00:09:58,281 --> 00:10:03,456 where we are calling the DealDamage and by having a mechanism that says as health, 191 191 00:10:03,456 --> 00:10:07,433 as you're hit, then decrease your health until you get to 0. 192 192 00:10:07,433 --> 00:10:12,580 And then I noticed one little bug which is the fact that we hit 0, so we twice 193 193 00:10:12,580 --> 00:10:18,577 on 0 health but the attacker wasn't destroyed, and that's cuz we're saying <0. 194 194 00:10:18,577 --> 00:10:21,955 So we need to say <=0. 195 195 00:10:21,955 --> 00:10:25,595 We'll try that one more time, click on Play, 196 196 00:10:25,595 --> 00:10:29,760 hopefully we hit this lizard, 197 197 00:10:29,760 --> 00:10:34,318 it will be once, and then he did a second time, and it should disappear. 198 198 00:10:34,318 --> 00:10:36,318 There we go, fantastic. 199 199 00:10:36,318 --> 00:10:39,438 A few little bits and pieces we can tidy up but that is good for this video. 200 200 00:10:39,438 --> 00:10:41,298 I think we got our core functionality in. 201 201 00:10:41,298 --> 00:10:43,978 Let's put in a little bit more of that finesse in the next video. 202 202 00:10:43,978 --> 00:10:45,128 So see you again shortly. 19659