WEBVTT 00:06.900 --> 00:07.990 Welcome back. 00:08.010 --> 00:14.280 So now that we know about gameplay tags and how to add them to our project and we have a few here, 00:14.310 --> 00:20.080 let's see how we can add gameplay tags to any given ability system component. 00:20.100 --> 00:22.560 We can do this in a number of ways. 00:22.560 --> 00:25.080 One of those ways is gameplay effects. 00:25.290 --> 00:29.190 Now let's see what happens if we take one of our crystals. 00:29.190 --> 00:36.300 Here's a health crystal, I'm going to duplicate one of them and bring it over next to my player start. 00:36.960 --> 00:44.070 Okay, so we know that we can pick one up and for one second our health starts to increase. 00:44.250 --> 00:49.860 And that's thanks to our gameplay effect in that crystal, which is in Blueprints. 00:49.890 --> 00:55.560 Actor Crystal and the Health crystal uses crystal Heal. 00:55.590 --> 00:58.980 Now this is a periodic gameplay effect. 00:59.010 --> 01:08.980 Now gameplay effects can have tags and under the tag section we have a lot of different types of tags 01:08.980 --> 01:10.960 and they all do different things. 01:11.110 --> 01:19.060 This makes the gameplay effect extremely versatile, but also maybe a little bit confusing as you don't 01:19.060 --> 01:21.700 really know which tags to use and when. 01:22.030 --> 01:29.260 So we'll quickly go over all the different types of tags and then we'll add a tag to Crystal Heal and 01:29.260 --> 01:33.610 see how we can add that to Aura's ability system component. 01:33.610 --> 01:36.850 So let's go in order from top to bottom. 01:36.850 --> 01:40.450 First we have gameplay effect asset tag. 01:40.890 --> 01:45.400 And if we expand that, we have combined tags added and removed. 01:45.420 --> 01:49.200 Now, if we hover over these, we get useful comments. 01:49.200 --> 01:56.580 This one says the gameplay effects tags, tags, the gameplay effect has and does not give to the actor. 01:56.610 --> 02:03.870 Okay, so that's good to know if we put some tags here when the gameplay effect gets applied, it's 02:03.870 --> 02:09.980 not going to give those tags to the actors ability system component, it just has the tags. 02:09.990 --> 02:11.550 So why is that useful? 02:11.550 --> 02:14.970 Well, we're going to see very shortly why that is useful. 02:14.970 --> 02:15.660 Now. 02:15.660 --> 02:19.880 Why are there three types combined, added or removed? 02:19.890 --> 02:28.230 Well, hovering over combined says tags that I inherited and tags that I added minus tags that I removed. 02:28.260 --> 02:33.270 This is what we'll see in all tag containers. 02:33.270 --> 02:38.550 And that's what these are, is gameplay tag containers that exist in all the engine classes. 02:38.580 --> 02:43.360 Now, it doesn't make a whole lot of sense here in a gameplay effect because we don't typically subclass 02:43.360 --> 02:51.220 gameplay effects, so we don't create inheritance hierarchies of gameplay effects, but we do sometimes 02:51.220 --> 02:55.090 make inheritance hierarchies of other gas classes. 02:55.090 --> 02:55.930 So we'll see. 02:55.930 --> 03:03.850 This trend now added is the comment, says tags that I have in addition to my parents tags. 03:03.850 --> 03:10.300 So a class will inherit its parents tags, but it can add its own. 03:10.300 --> 03:17.260 So in other words, if we want to add a tag to this container, we would add it here now removed, says 03:17.290 --> 03:20.530 tags that should be removed if my parent had them. 03:20.530 --> 03:25.450 So again, we won't be creating a child from any gameplay effect. 03:25.450 --> 03:31.690 But if we did, if this were a child, for example, it would inherit its parents gameplay tags. 03:31.690 --> 03:37.090 And if we wanted this child to not have one of those inherited tags, we would add that to the removed 03:37.090 --> 03:38.170 section here. 03:38.170 --> 03:46.330 Now we know that adding a tag to gameplay effect asset tag doesn't give that tag to the actor that's 03:46.330 --> 03:48.310 being hit by this effect. 03:48.310 --> 03:48.880 Right? 03:48.970 --> 03:55.840 So let's continue down to the next one which is granted tags, and if we expand it, we see the same 03:55.840 --> 03:58.780 thing combined, added and removed here. 03:59.170 --> 04:05.950 Now hovering over granted, we see these tags are applied to the actor I am applied to. 04:06.220 --> 04:06.910 Okay. 04:06.910 --> 04:14.320 So that means if we put a tag in here, it will be applied, it will be given to whatever we hit with 04:14.320 --> 04:15.220 this effect. 04:15.220 --> 04:16.780 So let's see how that works. 04:16.780 --> 04:20.920 Let's add one and we add one with the added right. 04:20.920 --> 04:27.400 So we can click on the dropdown and let's just add attributes, vital health. 04:27.400 --> 04:33.940 We'll add that and you'll see that as we click on the checkbox for health, we can add the tag and it 04:33.940 --> 04:40.510 appears here now to remove it, we just hit the red X, So adding and removing is pretty simple now 04:40.510 --> 04:43.900 because tags are hierarchical, we could add part of that tag. 04:43.900 --> 04:48.160 For example, attributes vital if we wanted to do that. 04:48.160 --> 04:53.140 And that just is a showcase of how versatile tags can be. 04:53.140 --> 04:57.100 But we're going to add attributes, vital health. 04:57.100 --> 05:00.060 Let's add that now we can add multiple, right? 05:00.070 --> 05:04.150 We can expand the dropdown and check multiple checkboxes. 05:04.150 --> 05:06.550 And as we add them, we'll see them here. 05:06.730 --> 05:13.120 And of course we can hit the X here to remove them or we can expand the dropdown and just uncheck those 05:13.120 --> 05:15.400 checkboxes and that does the same thing. 05:15.400 --> 05:16.810 It also removes them. 05:17.020 --> 05:22.360 So we've added attributes vital health to the granted tags. 05:22.360 --> 05:27.220 Now as soon as I compile, watch the combined tags here, I'm going to hit compile. 05:27.340 --> 05:34.510 And now we see that all of the tags we added to the added section are now in combined tags. 05:34.510 --> 05:41.020 And if the parent class of this had some tags and it's granted tags, we'd see those here too. 05:41.020 --> 05:41.830 But it doesn't. 05:41.830 --> 05:42.580 So we don't. 05:42.580 --> 05:49.450 But because we added one to the added section, it's now in combined tags and we see that as soon as 05:49.450 --> 05:55.060 we compile, if we remove it from added and then compile again, it goes away. 05:55.060 --> 05:56.980 It's no longer in combined tags. 05:56.980 --> 06:04.210 So anyway, let's put that health tag back into the added section we can compile and let's see what 06:04.210 --> 06:04.930 happens. 06:04.930 --> 06:14.770 I'm going to press play and show debug ability system and keep your eye right up here on owned tags 06:14.770 --> 06:17.680 and let's pick up the crystal and there it is. 06:17.710 --> 06:18.760 Attributes vital health. 06:18.760 --> 06:26.230 It was only there for a second because it gets removed as soon as this gameplay effect expires. 06:26.260 --> 06:31.800 To make this a little easier to see, let's change the duration magnitude. 06:31.810 --> 06:33.340 Here's the duration magnitude. 06:33.340 --> 06:34.240 It's set to a second. 06:34.240 --> 06:35.650 Let's set it to four seconds. 06:35.650 --> 06:36.970 That's a little easier. 06:36.970 --> 06:40.270 And then we can press play, show, debug and pick up. 06:40.340 --> 06:43.460 The crystal, keeping our eye on owned tags. 06:43.760 --> 06:48.800 And there it is attributes vital health and notice in parentheses it has a one there. 06:48.800 --> 06:58.070 We can keep count of these now that's because tags can be stacked much like gameplay effects can be 06:58.070 --> 06:58.580 stacked. 06:58.580 --> 07:00.650 But there's a key difference here. 07:00.680 --> 07:08.930 Our crystal health has its stacking type set to aggregate by target with a stack limit count of one. 07:08.960 --> 07:12.890 Okay, so we can only stack one, but let's say we increase that. 07:12.890 --> 07:15.530 Let's say we want to be able to stack four at a time. 07:15.830 --> 07:20.690 You might expect that we would stack those gameplay tags that are granted. 07:20.690 --> 07:24.080 In other words, this attributes vital health tag. 07:24.080 --> 07:29.150 You would expect us to add that tag four times and we'd get four stacks. 07:29.150 --> 07:30.860 But that's not how it works. 07:30.860 --> 07:37.400 You see, if we're applying crystal health and it's stackable, in this case it is. 07:37.400 --> 07:43.680 We're only going to get that tag once because it counts as just a single application of the gameplay 07:43.680 --> 07:44.400 effect. 07:44.400 --> 07:46.920 Only it has stacks, right? 07:46.920 --> 07:54.780 And based on the stacking policy and all of these parameters, the meaning of that depends on all these 07:54.780 --> 07:55.710 settings. 07:55.710 --> 08:04.140 So if I duplicate a few of these, let's have say three of them here and press play and show debug and 08:04.140 --> 08:11.250 pick them all up, we still just have a single health tag until they're all gone and then it's gone. 08:11.580 --> 08:18.840 So with a stackable effect, we just get that tag once because it's the effect that stacks, it's the 08:18.840 --> 08:22.310 effect stack count that goes up when we get multiples. 08:22.320 --> 08:26.790 However, let's say that this is not a stackable effect. 08:26.790 --> 08:31.770 If we take our stacking type and set it to none now, it doesn't stack anymore. 08:31.770 --> 08:38.610 We just apply the effect multiple times and each time counts as a new gameplay effect. 08:38.610 --> 08:40.470 Let's see what happens now. 08:40.500 --> 08:45.750 We'll show debug and pick up all three of these, keeping our eye on the owned tags. 08:45.750 --> 08:50.670 And now we see that we have three of the attributes vital health tags. 08:50.670 --> 08:56.520 And then it went down to two and then down to one when those effects expired. 08:56.670 --> 09:02.850 So that's a key difference between stacked effects and stacked tags. 09:02.850 --> 09:11.430 If our effect doesn't stack, then we'll get multiple effects applied, each of which adds that tag 09:11.460 --> 09:13.380 to the ability system component. 09:13.380 --> 09:18.120 And when the same tag gets added twice, then the tag count goes up. 09:18.120 --> 09:25.230 But if this is a stackable effect, if we set its stacking type to anything other than none, then applying 09:25.230 --> 09:32.130 this effect multiple times means that the effect stack goes up and we're only going to apply that tag 09:32.130 --> 09:32.820 once. 09:32.850 --> 09:33.900 Makes sense. 09:34.110 --> 09:41.190 Okay, so now we know we can add a tag when a duration based effect is added. 09:41.190 --> 09:42.660 So that's nice. 09:42.840 --> 09:48.360 And there are ways to respond to when a tag gets added to an ability system component so that can be 09:48.360 --> 09:49.110 useful. 09:49.320 --> 09:55.140 What happens though, if we add a tag to say, an instant gameplay effect? 09:55.140 --> 09:58.590 We know that these potions have instant gameplay effects. 09:58.590 --> 10:06.600 Let's go back into our potion folder into G potion mana and let's go to our granted tags and let's add 10:06.600 --> 10:07.080 a tag. 10:07.080 --> 10:09.000 Let's add the mana tag to it. 10:09.030 --> 10:12.060 Let's see what happens if we pick up one of the potions. 10:12.060 --> 10:15.690 I'm going to show debug keeping my eye on the own tags. 10:15.690 --> 10:17.340 I'm going to pick up a potion. 10:17.460 --> 10:22.290 Wait a minute, there's nothing there so we don't see anything. 10:22.410 --> 10:24.390 So that tells us something, right? 10:24.390 --> 10:32.250 Granted, tags really only mean something when our effect has a duration, because when the effect is 10:32.250 --> 10:34.680 gone, the tag is removed. 10:34.680 --> 10:40.350 And if it's an instant effect, well, there's no period during which we have the tag. 10:40.350 --> 10:41.490 We don't get it. 10:41.490 --> 10:45.050 So it doesn't matter in an instant gameplay effect. 10:45.050 --> 10:47.570 So I'm just going to clear that doesn't matter. 10:47.750 --> 10:51.230 But what happens if we want to receive a tag anyway? 10:51.560 --> 10:58.520 What happens if we pick up a potion and we want to know based on some gameplay tag that we just picked 10:58.520 --> 11:04.490 up a potion and we want to show something to the screen, we want to display a message that says Picked 11:04.490 --> 11:05.750 up Health Potion. 11:05.750 --> 11:14.570 Well, that's where our gameplay effect asset tag container comes in because we have ways to know when 11:14.570 --> 11:17.000 any type of effect has been applied. 11:17.030 --> 11:20.870 The ability system component has lots of ways to know. 11:20.900 --> 11:22.970 We're going to learn about those ways to know. 11:22.970 --> 11:29.060 In fact, we're going to peek at a couple of them in the code base now and then in the videos to come. 11:29.060 --> 11:30.800 We'll make use of them. 11:30.800 --> 11:36.860 So I'm going to undo what we did by removing that tag from crystal heal. 11:36.860 --> 11:38.840 We don't want to use granted tags. 11:38.840 --> 11:40.160 So removing that tag. 11:40.570 --> 11:42.730 And closing those gameplay effects. 11:42.730 --> 11:44.410 I don't need project settings. 11:44.410 --> 11:46.120 I'm going to close that as well. 11:46.510 --> 11:48.370 Make sure everything is saved here. 11:48.370 --> 11:54.580 I'm going to close out of the editor and I'd like to take a look at the Ability system component class. 11:54.670 --> 12:00.850 Now here in Writer, I can hit shift, shift and search for ability system component. 12:00.850 --> 12:08.550 Here's the header file and it can actually be really informative to just go through this class, right? 12:08.560 --> 12:09.760 It's a big class. 12:09.760 --> 12:15.790 There are almost 2000 lines of code, but it's an informative class. 12:15.790 --> 12:18.370 It's filled with comments everywhere. 12:18.400 --> 12:23.440 This is basically your documentation for gas is the code itself. 12:23.440 --> 12:25.330 It's filled with comments. 12:25.330 --> 12:28.450 This is basically Epic's documentation for gas. 12:28.450 --> 12:36.880 And if you're not pressed for time, I recommend just sitting down and reading through ability system 12:36.880 --> 12:37.640 components. 12:37.660 --> 12:42.170 H Read all the comments, read everything because it's all going to make sense. 12:42.170 --> 12:46.820 And you'll also see the things that the ability system component has. 12:46.820 --> 12:54.260 So while you don't have to, it might sound like torture to you to read 2000 lines of code, but I do 12:54.260 --> 12:55.340 recommend it. 12:55.340 --> 12:58.700 I recommend just sitting through, even just skimming through. 12:58.730 --> 13:00.500 You don't have to look at all the code. 13:00.500 --> 13:04.460 Just look at the comments and the names of the functions and variables. 13:04.460 --> 13:05.180 That's it. 13:05.180 --> 13:10.280 Just skim through the comment, take note of what the function is called and move on. 13:10.280 --> 13:13.070 Skim through the comment and the functions without comments. 13:13.070 --> 13:14.840 Just take note that they're there. 13:14.840 --> 13:15.440 Right? 13:15.470 --> 13:21.230 This is going to let you know just what the ability system component class has in it. 13:21.230 --> 13:27.680 So that way in the future, if you want to do something, you can just think, well, I did see something 13:27.680 --> 13:29.810 back when I skimmed through it. 13:29.900 --> 13:32.750 Related to this, maybe that'll work, right? 13:32.750 --> 13:37.610 So anyways, that's just a piece of advice that I have for you. 13:37.730 --> 13:46.550 Now, after you've done that, I want you to search for your on game play effect applied. 13:46.550 --> 13:47.900 And look at this. 13:47.990 --> 13:55.370 Here's a declare multicast delegate three params called F on gameplay effect applied delegate. 13:55.370 --> 13:58.460 If we keep searching for this same thing, we'll see that. 13:58.460 --> 14:03.740 Here's a function on gameplay effect applied to target apply to self. 14:03.740 --> 14:10.910 And if we scroll just a bit past that, here we see some actual delegate variables. 14:11.180 --> 14:15.590 Now the comments are pretty useful here on gameplay effect. 14:15.590 --> 14:20.750 Applied Delegate to Self has a comment that says called on server. 14:20.750 --> 14:29.060 Whenever a G is applied to self, this includes instant and duration based games or gameplay effects 14:29.270 --> 14:31.190 now called on server. 14:31.190 --> 14:37.040 That's pretty significant and based on our replication policy, we should know whether or not gameplay 14:37.040 --> 14:38.750 effects will be replicated. 14:38.930 --> 14:41.630 In fact, let's pull up that table real quick. 14:41.630 --> 14:42.530 Here we go. 14:42.530 --> 14:47.780 It's good to go back and look at these things because this actually has more meaning for us now, doesn't 14:47.780 --> 14:48.320 it? 14:48.410 --> 14:54.140 Now that we're starting to get into gameplay effects now, we're not using full for anything. 14:54.140 --> 14:59.600 We're using mixed and minimal or uses mixed and the enemies use minimal. 14:59.600 --> 15:06.110 Now we see that in mixed gameplay effects are replicated to the owning client only gameplay cues and 15:06.110 --> 15:11.510 gameplay tags replicated to all clients and for minimal gameplay effects are not replicated. 15:11.510 --> 15:16.640 Gameplay cues and gameplay tags are okay, so that's good to know isn't it? 15:16.640 --> 15:24.500 And here we have a delegate that will be broadcast whenever any gameplay effect is applied to self. 15:24.500 --> 15:27.800 That means to this ability system component. 15:27.830 --> 15:32.180 We also have on gameplay effect applied delegate to target. 15:32.450 --> 15:39.350 So when a gameplay effect is applied to someone else, this includes instant and duration based games, 15:39.350 --> 15:43.400 and when it says duration based, it's counting both duration and infinite. 15:43.430 --> 15:47.780 Now next we have on active gameplay effect added delegate to self. 15:47.780 --> 15:53.360 Now this is gameplay effect added right not just applied but added. 15:53.360 --> 15:57.950 Whenever you see added, that means it's for duration based gameplay effects. 15:57.950 --> 16:02.120 And here it says instant gameplay effects did not trigger this. 16:02.120 --> 16:05.630 So this is only for duration or infinite. 16:05.660 --> 16:11.870 Here we have on periodic gameplay effect, execute delegate on self and it says called on server. 16:11.870 --> 16:18.830 Whenever a periodic gameplay effect executes on self, so say we have a periodic one right? 16:18.830 --> 16:21.680 Every second something is modified. 16:21.680 --> 16:27.320 Well, here's a delegate that will be broadcast on the periodic execution. 16:27.320 --> 16:32.870 And then here we have one for when a periodic GE is executing on a target. 16:32.870 --> 16:38.420 So in other words, we have a lot of different things that we can take advantage of here. 16:38.420 --> 16:39.080 Right. 16:39.140 --> 16:40.160 And. 16:40.230 --> 16:47.150 I like on gameplay effect applied because it includes instant and duration based gameplay effects. 16:47.160 --> 16:51.580 And of course we can do things when effects are removed as well. 16:51.600 --> 16:58.380 Let's search for on gameplay effect removed and we have a lot of things. 16:58.500 --> 17:00.540 Let's keep searching. 17:00.840 --> 17:06.990 Let's search for on any gameplay effect removed. 17:06.990 --> 17:12.570 And here's something that's called when any gameplay effects are removed. 17:12.690 --> 17:15.870 Now this is a function, but it returns the delegate. 17:15.900 --> 17:17.370 It returns a reference to it. 17:17.370 --> 17:23.700 So we'd have to call this function if we want to bind anything to this delegate and these delegates 17:23.700 --> 17:30.300 broadcast info right, we're going to be able to know what effect is being applied, added, removed, 17:30.300 --> 17:31.440 whatever we want. 17:31.470 --> 17:34.560 The ability system component has you covered. 17:34.590 --> 17:35.190 Okay. 17:35.190 --> 17:41.740 So in the videos to come, we're going to bind some stuff to these delegates so we can know and then 17:41.740 --> 17:45.520 we can get those delegates and perhaps see what tags they have. 17:45.520 --> 17:50.290 And that will allow us to retrieve tags for a gameplay effect. 17:50.290 --> 17:52.660 That's perhaps instant, right? 17:52.660 --> 17:58.570 And then we don't have to rely on duration based effects if we want to do something in response to a 17:58.570 --> 18:02.390 gameplay effect applied to us, like showing something in the HUD. 18:02.410 --> 18:03.700 So excellent job. 18:03.700 --> 18:07.090 I hope you at least skim through the ability system component. 18:07.120 --> 18:12.910 If you're super curious, you can go to the CPP file and see the implementation details of it as well. 18:13.060 --> 18:18.610 So do that if you're so inclined, and I'll see you in the next video.