WEBVTT 00:00.000 --> 00:00.420 Hello guys. 00:00.420 --> 00:01.410 Welcome to the video. 00:01.410 --> 00:05.070 In this one we're going to learn how to work with the Trigger Collider. 00:05.070 --> 00:10.170 So this is going to be useful for many things in the game including knockback and the player from a 00:10.170 --> 00:13.320 trap and picking up fruits for a player as well. 00:13.440 --> 00:14.730 So let's just learn. 00:14.730 --> 00:15.930 How does it work. 00:15.930 --> 00:18.330 We can create an empty object. 00:19.220 --> 00:21.290 Let's just call it trigger for now. 00:21.800 --> 00:23.360 Let's find this object. 00:24.300 --> 00:29.160 Let's place it somewhere here and let's add a box collider to this object. 00:30.170 --> 00:32.180 I want to make this bigger. 00:32.180 --> 00:34.610 So I'm going to make maybe a size two by two. 00:36.060 --> 00:37.860 And we're going to place it over here. 00:37.950 --> 00:43.530 Now let's go to the game and you can see if I come to this collider and I try to walk inside, it's 00:43.530 --> 00:44.430 not going to work. 00:44.430 --> 00:48.570 And that is very obvious because this is a collider and we cannot pass by the collider. 00:48.570 --> 00:55.800 But if we click is trigger over here, then it becomes a trigger area and we can walk through the collider. 00:55.800 --> 01:02.370 Now this is very helpful because we can not only walk through the collider, but also we can check what 01:02.370 --> 01:04.470 entered the trigger area. 01:05.010 --> 01:07.320 Let's make a quick script over here. 01:07.320 --> 01:11.730 Let's do let's call it damage Trigger. 01:12.330 --> 01:13.200 Just like that. 01:14.580 --> 01:19.290 Now we can go inside of this script, and over here we have nothing. 01:19.290 --> 01:23.220 But we're going to type on trigger enter to D. 01:23.550 --> 01:28.080 So now this method will be called every time something collides with a trigger. 01:28.080 --> 01:33.030 When we enter in the trigger, I want to be sure that player entered the trigger. 01:33.030 --> 01:34.500 There are many ways to do that. 01:34.500 --> 01:36.450 One of them is to use tag. 01:36.450 --> 01:40.920 I'm going to show you how to use tags to detect player, but after that I'm not going to use it because 01:40.920 --> 01:42.180 I prefer another way. 01:42.180 --> 01:44.160 And I'm going to show you another way on how to do that. 01:44.160 --> 01:44.550 Okay. 01:44.550 --> 01:45.720 So let's do this. 01:45.720 --> 01:50.640 If collision dot tag equals to player. 01:50.640 --> 01:54.090 And here it is very important to have a very same name as a tag. 01:54.120 --> 01:56.880 So type it just as I did it over here. 01:56.880 --> 02:02.790 And then we're going to do debug log player enter trigger. 02:03.950 --> 02:04.850 Just that. 02:05.000 --> 02:06.530 Now let's go back. 02:07.260 --> 02:11.550 Let's find the player and let's give it a tag of a player. 02:11.820 --> 02:16.380 And let's select the trigger and make sure we check is trigger. 02:16.740 --> 02:18.630 Now we can go to play mode again. 02:20.260 --> 02:24.940 And in the console message, you'll see that player entered trigger. 02:24.970 --> 02:30.040 Now, as you can understand, we not only can debug the message, but also we can do a knockback. 02:30.040 --> 02:31.180 For example. 02:31.510 --> 02:33.430 Uh, let's go ahead. 02:36.230 --> 02:42.020 And instead of this we're going to the game manager dot instance player knockback. 02:43.090 --> 02:44.110 Just like that. 02:44.110 --> 02:46.120 Let's go ahead and save this. 02:48.780 --> 02:50.040 And now you'll see. 02:50.040 --> 02:53.610 When we go in close to this box, we're going to get knocked. 02:54.630 --> 02:55.830 Very cool rate. 02:56.640 --> 02:58.050 Yeah, I like it a lot. 02:58.080 --> 03:02.850 Now, what I was talking about, I really don't like to do it this way, because this kind of reminds 03:02.850 --> 03:03.840 me of spaghetti. 03:03.840 --> 03:09.750 We need to go to the game manager to call the player so we can call the knockback method. 03:10.780 --> 03:12.400 What else we can do. 03:12.430 --> 03:15.130 And although it's not that bad, it's actually very efficient. 03:15.130 --> 03:17.650 But sometimes people make mistake with the tags. 03:17.650 --> 03:23.590 Sometimes tags can be used for something else, and sometimes people just don't prefer it this way as 03:23.590 --> 03:24.100 I do. 03:24.310 --> 03:25.960 So this is what we're going to do. 03:25.990 --> 03:28.660 We can type here player, player. 03:28.660 --> 03:31.090 And this is going to be a local variable of a player. 03:31.090 --> 03:36.190 And it's going to be equals to collision GameObject Getcomponent of a player. 03:36.430 --> 03:44.350 Now this variable is going to have a value only if we can find component of a player on this object 03:44.350 --> 03:46.900 that entered the trigger on the collision. 03:46.900 --> 03:48.310 And then we're going to type this. 03:48.310 --> 03:56.170 If player not equals to null which checks if we assign the component then we're going to do player knockback. 03:56.170 --> 04:00.610 Now this method is much more independent and we can use it just like that. 04:01.330 --> 04:04.900 Uh let's go ahead and see if this works. 04:05.530 --> 04:06.970 We're going to go back. 04:08.960 --> 04:10.370 We're going to go to play mode. 04:11.660 --> 04:14.600 And we were knocked back. 04:15.190 --> 04:15.850 Very cool. 04:15.850 --> 04:16.540 Right. 04:16.570 --> 04:19.540 Now let's go back here and I'm going to show you something else. 04:20.080 --> 04:26.530 We can check if this one is not null by just typing a question mark over here. 04:26.860 --> 04:30.190 And then we do need this line of code just like that. 04:34.850 --> 04:39.650 So this one basically, uh, very similar to the null check over here. 04:39.650 --> 04:42.200 It's like asking player to knock back. 04:42.200 --> 04:44.990 And if no one responds, then there is no knock back. 04:45.050 --> 04:46.970 Let's go ahead and try this. 04:53.700 --> 04:55.830 And boom knocked. 04:56.280 --> 04:57.180 Very cool. 04:57.210 --> 05:00.240 However, I do not recommend to use this one. 05:00.240 --> 05:03.090 Let's just do it. 05:03.090 --> 05:03.450 Uh. 05:04.510 --> 05:05.350 Like so. 05:07.500 --> 05:08.130 Okay. 05:09.700 --> 05:10.630 Very well. 05:10.630 --> 05:13.090 So that's all what we need here and now. 05:13.090 --> 05:19.270 Every time we make a trap or an enemy, we can just make a trigger area on that trap and assign this 05:19.270 --> 05:20.920 script together with the trigger. 05:20.920 --> 05:22.180 And it's going to work just like that. 05:22.180 --> 05:24.490 We're going to damage enemy with whatever we need. 05:24.490 --> 05:29.320 As of now, I'm just going to delete this trigger and I want to do a bit of a clean up. 05:29.320 --> 05:31.030 So let's make a folder. 05:31.770 --> 05:37.020 You're going to call it scripts, and we're going to take all of the scripts we have and drag them inside 05:37.020 --> 05:43.650 of this folder, because if we don't manage everything from the start, it can make quite a mess in 05:43.650 --> 05:45.150 this window. 05:45.480 --> 05:50.610 Also, for the material, we don't really have any other materials in the game, but still I'm going 05:50.610 --> 05:55.500 to make a folder, I'm going to call it material and I'm going to drag it here. 05:55.530 --> 05:56.130 Okay. 05:56.130 --> 05:56.880 Very cool. 05:56.880 --> 05:58.590 Let's go to the next video.