WEBVTT 00:07.470 --> 00:08.730 Welcome back. 00:08.730 --> 00:14.730 Now that we're applying damage effect well we're not applying it, but our apply damage effect function 00:14.730 --> 00:18.870 is now setting our radial damage parameters. 00:18.870 --> 00:25.500 We can harvest these at any point along the damage pipeline where we can access the context handle. 00:25.500 --> 00:29.100 And I'd like to access it from within the exec calc. 00:29.100 --> 00:37.620 So I'm going to close all tabs and go into my exec calc and Ability system exec calc damage right here. 00:37.980 --> 00:45.120 And here's where all the magic is happening with damage, where looping through all damage types to 00:45.120 --> 00:49.740 resistances that map that exists in or a gameplay tags. 00:49.740 --> 00:51.480 And what are we doing? 00:51.480 --> 00:59.550 Well, we're getting our resistance that corresponds to that damage type and where decreasing the damage 00:59.550 --> 01:01.470 based on that resistance. 01:01.970 --> 01:03.320 So that's all fine. 01:03.320 --> 01:04.490 That's all good. 01:04.490 --> 01:13.190 But after we've done that, what we need to do with that damage is determine if we have radial damage. 01:13.190 --> 01:20.750 Because if this is radial damage, then we need to scale it down based on the distance of the victim 01:20.750 --> 01:23.870 from the origin of damage. 01:23.870 --> 01:31.490 So at this point, after we've checked and reduced our damage based on resistances, we can then see 01:31.490 --> 01:38.840 if we need to lower it even more based on the distance, if it's radial, and we can do this per damage 01:38.840 --> 01:39.770 type. 01:39.770 --> 01:44.930 So if this is radial damage, we're going to be scaling the damage down. 01:44.930 --> 01:50.810 Now if we're doing this per damage type then we have a damage type value. 01:50.810 --> 01:56.390 And we can scale that damage type value down before adding it to the damage total. 01:56.390 --> 02:04.850 So before incrementing damage for this given damage type but after we've taken resistances into account, 02:04.850 --> 02:08.090 we can then check to see if we need to apply radial damage. 02:08.090 --> 02:09.800 That's the order I'm going to do it in. 02:09.800 --> 02:13.550 You could do it before taking resistances into account. 02:13.550 --> 02:14.690 It's up to you. 02:14.690 --> 02:16.130 So how are we going to do it? 02:16.130 --> 02:18.200 Well, we need to check our context. 02:18.200 --> 02:21.680 We need our gameplay effect context, don't we? 02:21.830 --> 02:29.030 Now if we search here for context, we'll see that we have f gameplay effect, context handle spec dot 02:29.030 --> 02:30.170 get context. 02:30.170 --> 02:32.540 So here's our effect context handle. 02:32.540 --> 02:33.650 It's right there. 02:33.650 --> 02:34.850 And we're getting it. 02:34.850 --> 02:38.090 It looks like below where we're calculating damage. 02:38.090 --> 02:44.180 But that's not to say that we can't just get it higher up before we need it so that it's in scope. 02:44.270 --> 02:50.780 So I'm going to control X to cut it and move it up towards the beginning of the function way up towards 02:50.780 --> 02:51.470 the top. 02:51.470 --> 02:57.110 We'll just do it as soon as we have the spec right here, we can get our gameplay effect context handle 02:57.110 --> 02:57.770 then. 02:58.360 --> 03:05.440 And now when we're checking damage, we can check that context handle to see if we have radial damage. 03:05.470 --> 03:16.600 So I'm going to say if you aura ability system library is radial damage passing in that effect context 03:16.600 --> 03:17.350 handle. 03:18.300 --> 03:22.650 If it is radial damage, then what are we going to do? 03:22.680 --> 03:29.250 You see, we could apply radial damage with falloff using the U gameplay statics function, but that's 03:29.250 --> 03:35.190 just going to result in that actor that we damage having its take damage function called. 03:35.190 --> 03:40.110 But how are we going to know the result of that once that happens? 03:40.140 --> 03:42.810 Well, that's what delegates are good for. 03:42.870 --> 03:47.490 If we get a delegate we can bind to, we can even bind a lambda to it right here. 03:47.490 --> 03:51.090 Then we can call apply radial damage with falloff. 03:51.090 --> 03:55.920 And in the character's take damage function we could broadcast the final damage amount. 03:55.920 --> 03:59.310 So it's kind of a roundabout way, but it's also a clever way. 03:59.310 --> 04:03.330 So I'm going to map this out because that might have sounded a little confusing. 04:03.330 --> 04:05.490 First I'm going to say one. 04:05.490 --> 04:06.870 Let's put some pseudo code here. 04:06.870 --> 04:15.630 One we're going to override take damage, and we'll do this in the base character class in our character 04:15.630 --> 04:17.820 base. 04:18.450 --> 04:33.030 Two we're going to create delegates and we can call it on damage delegate and broadcast damage received 04:33.030 --> 04:34.440 and take damage. 04:36.910 --> 04:43.420 Three we're going to bind to on damage delegate on the. 04:43.420 --> 04:44.830 We'll call it the victim. 04:46.460 --> 04:47.390 Here. 04:49.120 --> 04:50.170 For? 04:50.470 --> 04:50.920 What? 04:50.920 --> 04:51.940 Are we going to bind it? 04:51.940 --> 04:54.220 Let's just say we're going to bind a lambda. 04:55.150 --> 05:02.320 And then in four we'll say call apply radial damage with falloff. 05:03.570 --> 05:12.360 That's you gameplay statics you gameplay statics apply radial damage with falloff to cause damage and 05:12.360 --> 05:13.380 parentheses. 05:13.380 --> 05:20.940 This will result in take damage being called on the victim. 05:22.630 --> 05:28.210 Which will then broadcast on damage delegate. 05:29.760 --> 05:31.140 And five. 05:31.890 --> 05:42.780 In Lambda here in our response, set damage type value to the damage received from the broadcast. 05:44.070 --> 05:48.270 So now these steps are planned out and it's a little bit more clear what to do. 05:48.270 --> 05:49.500 And we have a list. 05:49.590 --> 05:52.290 So this is how we're going to implement this. 05:52.350 --> 05:58.980 Now how are we going to bind to that delegate from right here without say casting to or a character 05:58.980 --> 06:06.390 base, which is a practice that I tend to shy away from because it makes the exact calc very specific. 06:06.390 --> 06:13.770 I like to use interface functions instead, so we're going to probably end up using an interface, but 06:13.770 --> 06:20.370 it's nice when we have a set of steps like this, because then we can just follow the steps and it makes 06:20.370 --> 06:22.020 the task a lot easier. 06:22.020 --> 06:24.180 So let's take this one step at a time. 06:24.180 --> 06:27.300 Let's override take damage in or a character base. 06:27.890 --> 06:34.400 So we'll go ahead and open our public folder, go to Character Get or a character base open. 06:34.400 --> 06:38.300 And we'll just do it right here in the public section. 06:38.300 --> 06:42.350 Virtual void take damage. 06:43.280 --> 06:47.780 Now it's not auto completing for me because it's actually not a void function. 06:47.780 --> 06:49.550 Take damage returns a float. 06:49.550 --> 06:56.480 That's also one of the reasons why it's so useful, because whatever take damage receives as a result 06:56.480 --> 07:01.850 of gameplay statics calling it, or anything else in the damage system it receives, the amount of damage 07:01.850 --> 07:08.840 taken, and then whatever we decide to return here is returned, so we can return that damage as well. 07:08.840 --> 07:12.020 So take damage takes in a float. 07:12.020 --> 07:15.770 In fact, we should be able to get auto complete to work for us. 07:15.770 --> 07:17.930 Now I'm just going to type it again. 07:17.930 --> 07:19.280 Virtual float. 07:20.480 --> 07:21.440 Take damage. 07:21.440 --> 07:22.250 There we go. 07:22.340 --> 07:24.170 Now writer auto completes it. 07:24.170 --> 07:25.040 So take damage. 07:25.040 --> 07:32.540 Takes in damage amount as a float and if damage event const called damage event and a controller called 07:32.540 --> 07:38.000 instigator event instigator rather and an a actor called damage causer. 07:38.300 --> 07:43.130 So with that we can go ahead and generate a definition. 07:43.130 --> 07:46.310 And now we've overridden take damage. 07:47.450 --> 07:48.020 Perfect. 07:48.020 --> 07:49.310 That was step one. 07:49.310 --> 07:50.990 Let's go back and look at our step. 07:50.990 --> 07:52.580 We can add a check mark. 07:52.580 --> 07:55.970 I'll just use an asterisk to say we're done with this step. 07:55.970 --> 08:02.510 Next create a delegate on damage delegate broadcast damage received and take damage. 08:02.510 --> 08:08.210 So we need a delegate so we can go back to our character base and we can declare a delegate. 08:08.210 --> 08:13.820 We can go all the way up to the top above our includes and just declare one here, and I'm just going 08:13.820 --> 08:15.200 to make it multicast. 08:15.200 --> 08:18.410 I only plan on binding to it and C plus plus. 08:19.280 --> 08:21.170 So declare multicast delegate. 08:22.750 --> 08:28.930 And it needs to broadcast one param, which is going to be the damage amount. 08:28.930 --> 08:33.460 So I'm going to call this F on damage signature. 08:33.940 --> 08:40.540 It's going to broadcast a float and I'm going to just put here damage amount. 08:42.170 --> 08:44.630 So it's clear that that's what that float is for. 08:44.660 --> 08:48.590 Then we can add a public variable here for this. 08:48.590 --> 08:53.240 I'll put it down here with our delegates and I'll call this on damage delegate. 08:53.780 --> 08:55.640 And then let's look at our list. 08:55.640 --> 09:01.400 It says create the damage delegate on damage delegate broadcast damage received and take damage. 09:01.400 --> 09:10.640 So here in our character base, what I'm going to do is after super has calculated take damage, I'm 09:10.640 --> 09:13.490 going to store that in a float called Damage Taken. 09:14.600 --> 09:22.010 And I'm going to broadcast that on damage delegate dot broadcast damage taken. 09:24.560 --> 09:27.200 And then this function can return damage taken. 09:27.890 --> 09:29.210 So pretty simple. 09:29.210 --> 09:33.770 And this can even be, you guessed it, a cost. 09:33.770 --> 09:38.450 So take damage as simple, it just takes damage and broadcast the delegate. 09:38.450 --> 09:42.710 So now in exact calc damage that step is done. 09:42.710 --> 09:44.180 We can go on to the next one. 09:44.180 --> 09:47.450 Bind a lambda to on damage, delegate on the victim here. 09:47.450 --> 09:52.490 And this is where interfaces come in, because we don't want to have to cast to or a character based 09:52.490 --> 09:53.960 just to get that delegate. 09:53.960 --> 09:58.220 I'd like a function in the combat interface that returns it. 09:58.220 --> 10:03.260 So let's go to combat interface and Interaction and we'll create one. 10:03.260 --> 10:09.110 And just like our other interface functions that return a delegate, we should return a reference. 10:09.110 --> 10:13.100 So we return the actual delegate without making a copy of it. 10:13.340 --> 10:20.690 So I'm going to just make a pure virtual function called f on. 10:21.410 --> 10:22.760 Damage signature. 10:22.760 --> 10:24.320 And you know what? 10:24.320 --> 10:32.540 I'm just now realizing that I declared this in or a character base if I use it here as a reference. 10:33.970 --> 10:36.280 I'm going to have to forward declare it, which I can. 10:36.280 --> 10:37.960 Actually, it's a reference. 10:37.960 --> 10:45.670 I can forward declare it here and I'm going to call this function get on damage signature. 10:47.690 --> 10:49.460 And this will be pure virtual. 10:49.460 --> 10:56.390 That should work and I can forward declare it up at the top, since that's the convention I've been 10:56.390 --> 11:00.200 using for this project, and it's good to stick to conventions. 11:00.200 --> 11:01.190 So we'll do that. 11:01.190 --> 11:03.320 And now we don't need to forward declare there. 11:03.770 --> 11:08.750 And now we can override F on damage signature and or a character base. 11:08.750 --> 11:09.800 Let's do that. 11:09.800 --> 11:21.230 So right here virtual F on damage signature ref get on damage signature override. 11:22.400 --> 11:22.730 Okay. 11:22.730 --> 11:25.490 So we're not going to be able to override this. 11:25.490 --> 11:33.500 And that's because we're overriding a function that has an incomplete type over in the combat interface. 11:33.500 --> 11:40.730 To make this work, what we should do is we should instead declare the delegate. 11:41.500 --> 11:43.060 In the combat interface. 11:44.440 --> 11:51.160 So I'm going to move that declaration into the combat interface and remove that forward declaration 11:51.160 --> 11:51.700 here. 11:52.750 --> 11:57.190 And it's not going to need that forward declaration here. 11:57.190 --> 12:01.060 Instead, we're going to use the forward declaration in or a character base. 12:02.210 --> 12:03.710 So we'll say struct. 12:04.780 --> 12:08.920 F on damage signature. 12:18.470 --> 12:24.980 So we're not actually going to even need to forward declare it here in our character base. 12:25.640 --> 12:34.160 And with that, we are now overriding a valid function and we can go ahead and provide the definition. 12:34.160 --> 12:40.100 By the way, if you were wondering if you could just define these on the same line like this return 12:40.100 --> 12:41.510 on damage delegate. 12:41.510 --> 12:42.770 Sure you could. 12:42.770 --> 12:43.550 Of course. 12:43.550 --> 12:47.600 Now it looks weird having this one and the others are not doing it. 12:47.600 --> 12:53.570 So rather than do that, I'm just going to be consistent and we'll return it here. 12:53.570 --> 12:54.560 Return. 12:56.110 --> 12:57.640 On damage. 12:57.670 --> 12:58.690 Delegate. 12:58.840 --> 12:59.380 Okay. 12:59.380 --> 13:03.250 So now our our character base is implementing that. 13:03.250 --> 13:06.340 And what we can do in exec calc damage is we can do. 13:06.340 --> 13:11.680 Step three bind a lambda to on damage delegate on the victim here. 13:11.740 --> 13:13.390 That's going to be right here. 13:13.390 --> 13:15.850 So how are we going to do that. 13:15.940 --> 13:18.820 Well we should have access to the victim. 13:19.060 --> 13:22.150 So if we scroll up what is our victim. 13:22.150 --> 13:23.950 Well that's going to be the target. 13:23.950 --> 13:26.560 And we have the target avatar right here. 13:26.710 --> 13:28.420 That's pretty convenient. 13:28.420 --> 13:31.480 This is the thing getting damaged, right? 13:31.480 --> 13:33.760 The target here in Exec Calc. 13:33.760 --> 13:39.250 So what we can do is we can cast the target avatar to our interface. 13:39.250 --> 13:41.470 We can say I combat interface. 13:41.500 --> 13:42.820 Combat interface. 13:42.820 --> 13:45.730 As long as we haven't used combat interface already. 13:45.820 --> 13:47.710 Let me just search for it. 13:49.680 --> 13:53.820 Okay, so we're checking if Source Avatar implements it up here. 13:55.410 --> 13:58.740 But this is actually the only place where we're casting to it. 13:58.740 --> 14:00.150 So this is fine. 14:00.150 --> 14:02.010 So we're going to cast to it. 14:03.180 --> 14:06.660 Cast to AI combat interface. 14:06.690 --> 14:07.380 Casting. 14:07.410 --> 14:07.860 Target. 14:07.860 --> 14:08.760 Avatar. 14:08.880 --> 14:10.440 And we'll go ahead. 14:10.440 --> 14:12.600 Wrap that in an if statement. 14:14.510 --> 14:23.330 And then we can take our combat interface and we can call the function get on damage signature. 14:23.330 --> 14:25.130 Now this returns that delegate. 14:25.130 --> 14:26.840 So we can just bind to it. 14:26.840 --> 14:31.610 And I'd like to bind a lambda just like my steps here are telling me to do. 14:31.700 --> 14:32.390 So. 14:32.390 --> 14:34.100 For that I can use add lambda. 14:35.510 --> 14:37.460 And I can make my lambda here. 14:37.460 --> 14:40.940 Square parentheses squigglies. 14:40.940 --> 14:43.880 And what am I going to do in here? 14:43.910 --> 14:47.600 Well this delegate broadcast afloat the damage amount. 14:47.600 --> 14:53.210 So I'm going to go ahead and use a float damage amount as my input parameter. 14:53.210 --> 14:59.090 And all I need to do in this is set my damage type value. 15:01.500 --> 15:03.270 Equal to damage amount. 15:05.730 --> 15:11.970 Now I can't set damage type value unless it's captured and I can't capture it by value. 15:11.970 --> 15:13.980 I have to capture it by reference. 15:13.980 --> 15:18.690 So by the way, you can just put a ampersand in here. 15:18.690 --> 15:21.600 And now you're capturing everything in here by reference. 15:21.600 --> 15:27.390 So setting damage type value in here will set damage type value out here. 15:27.810 --> 15:29.070 Pretty nifty. 15:29.100 --> 15:36.000 Now we're not just overwriting damage type value and getting rid of the work we've done here for resistances. 15:36.000 --> 15:37.830 Why are we not doing that? 15:37.860 --> 15:45.030 Well because this all happens in response to the character's take damage function. 15:45.030 --> 15:53.700 And take damage is going to receive the amount of our damage type value, but after taking the radial 15:53.700 --> 15:55.440 damage distance into account. 15:55.440 --> 15:59.970 So it's going to start off with damage type value and then nerf it based on distance. 15:59.970 --> 16:01.200 How is it going to do that? 16:01.200 --> 16:04.770 Well, we have to call apply radial damage with falloff. 16:04.770 --> 16:05.670 That's our next step. 16:05.670 --> 16:07.560 So we've bound the lambda. 16:07.560 --> 16:09.930 We can check off that part of the list. 16:09.930 --> 16:12.690 And now we're going to call you gameplay statics. 16:12.690 --> 16:16.890 Apply radial damage with falloff to cause damage. 16:16.890 --> 16:22.680 This will result in take damage being called on the victim, which will then broadcast the on damage 16:22.680 --> 16:25.020 delegate which we have lambda bound to here. 16:25.380 --> 16:29.820 And then in Lambda set damage type value to the damage received from broadcast. 16:29.820 --> 16:33.990 So we actually jumped the gun here and we did that step a little early. 16:33.990 --> 16:35.880 Now we just need to call number four. 16:35.880 --> 16:44.100 So what we do here is after we've bound the lambda here after that if statement there we're going to 16:44.100 --> 16:46.830 call apply radial damage with falloff. 16:46.830 --> 16:50.130 That's a you gameplay statics function. 16:50.820 --> 16:54.270 And I'm going to go ahead and make that include happen. 16:54.270 --> 16:55.710 So I can get auto complete. 16:55.710 --> 16:58.440 So apply radial damage with falloff. 16:58.440 --> 17:00.870 And this takes a ton of parameters. 17:00.870 --> 17:02.880 We need a world context object. 17:02.880 --> 17:05.520 I'm just going to pass in the target avatar. 17:05.520 --> 17:07.560 We need the base damage amount. 17:07.560 --> 17:12.840 And that's why I said that damage type value isn't just thrown out the window. 17:12.870 --> 17:20.730 We're passing in damage type value to this function now because we have a ton of input parameters. 17:20.730 --> 17:23.340 Let's start getting these on their own lines here. 17:23.790 --> 17:27.090 And after damage type value we have a minimum damage. 17:27.090 --> 17:28.950 I'm just going to use zero. 17:28.980 --> 17:31.140 I mentioned earlier that I would. 17:31.140 --> 17:38.970 So if outside of the damage radius will actually not receive any damage outside of that damage outer 17:38.970 --> 17:40.020 radius, that is. 17:40.020 --> 17:41.700 Now we need the origin. 17:41.700 --> 17:46.530 And this is where our handy ability system library functions come in. 17:46.530 --> 17:53.940 We're going to call you or Ability system library get damage origin or get radial damage origin. 17:53.940 --> 18:00.300 And we have to pass in our effect context handle in addition to that. 18:00.300 --> 18:03.990 Next we have damage inner radius and damage outer radius. 18:03.990 --> 18:12.600 So back to our ability system blueprint library functions get radial damage inner radius passing in 18:12.600 --> 18:14.370 the effect context handle. 18:16.310 --> 18:18.140 Next is the outer radius. 18:18.140 --> 18:19.460 So we'll get that. 18:23.280 --> 18:24.810 So radial damage. 18:24.810 --> 18:27.930 Outer radius passing in the effect context handle. 18:28.020 --> 18:29.550 Now damage falloff. 18:29.550 --> 18:33.810 We've seen that we'll get a nice linear falloff if that's one. 18:33.810 --> 18:39.330 And a faster sharper falloff exponentially if it's larger than one. 18:39.720 --> 18:49.560 Now for damage type class we can just use you damage type static class just to satisfy that input. 18:50.490 --> 18:53.640 Now we need an array of ignore actors. 18:53.640 --> 18:58.890 And I'm not going to ignore any actors here, so I'll pass in an empty array. 19:00.510 --> 19:01.320 Of a actor. 19:01.320 --> 19:02.070 Pointers. 19:04.510 --> 19:06.160 Now for the damage causer. 19:06.160 --> 19:07.660 We have a source actor. 19:09.450 --> 19:11.940 And that is not exactly what I wanted. 19:11.940 --> 19:14.490 Source actor is what I wanted. 19:16.880 --> 19:20.150 Oh, and it's auto completing because there is no source actor. 19:20.150 --> 19:21.740 It's called Source Avatar. 19:21.740 --> 19:25.820 So just like we have a target avatar, we have a source avatar. 19:25.820 --> 19:27.170 I'm going to pass that in. 19:27.170 --> 19:31.250 And finally an instigated by controller. 19:31.250 --> 19:35.780 Well, if we wanted to pass in a controller and use it, I don't have any use for it. 19:35.780 --> 19:45.050 But we could go on and say CoStar, source Avatar, and target avatar to characters. 19:45.050 --> 19:46.640 I don't think I need to do that. 19:46.640 --> 19:48.680 I'm going to pass in a null pointer. 19:48.680 --> 19:50.120 I don't plan on using that. 19:50.120 --> 19:53.960 So with that we're calling Apply radial damage with falloff. 19:54.440 --> 19:55.790 Now here's the trick. 19:55.790 --> 19:57.620 It's like a sleight of hand trick. 19:57.620 --> 19:57.950 Right. 19:57.950 --> 20:00.980 Because what we're doing is we're being sneaky here. 20:00.980 --> 20:05.300 We're taking our target actor that's getting damaged. 20:05.300 --> 20:10.490 We're getting its combat interface and getting the on damage signature and binding a quick little lambda 20:10.490 --> 20:16.040 to it and saying, hey, whenever you broadcast this delegate, my lambda is going to respond and it's 20:16.040 --> 20:21.800 going to set my damage type value to the damage amount, and then it turns around and causes damage 20:21.800 --> 20:22.730 to that actor. 20:22.730 --> 20:23.210 Right. 20:23.210 --> 20:25.040 And this happens right away. 20:25.040 --> 20:25.550 Gameplay. 20:25.550 --> 20:31.190 Static says, hey, calculate radial damage with falloff, then apply damage. 20:31.190 --> 20:37.670 And then of course, this actor that we just bound a lambda to instantly gets take damage called and 20:37.670 --> 20:38.660 it broadcasts this. 20:38.660 --> 20:41.690 So it's kind of a funny little loop that happens right here. 20:41.690 --> 20:43.790 But it causes radial damage. 20:43.790 --> 20:44.630 Pretty cool right. 20:44.630 --> 20:47.270 So that's pretty amazing. 20:47.630 --> 20:54.800 So with that we have just completed that step in our radial damage capability. 20:54.800 --> 20:57.410 We've added radial damage to our pipeline. 20:57.410 --> 21:02.420 All we have to do is set those radial damage params and then we'll get radial damage. 21:02.420 --> 21:03.740 So pretty exciting. 21:03.740 --> 21:06.830 And we're going to go ahead and just compile this. 21:06.830 --> 21:12.050 And then we'll get all this working in the next video where we tie it all together and set our damage 21:12.050 --> 21:15.530 params for our arcane shards. 21:15.530 --> 21:18.110 Excellent job and I'll see you in the next video.