WEBVTT 00:07.310 --> 00:08.320 Welcome back. 00:08.330 --> 00:15.770 Now, in our electrocute spell, we've just added a gameplay cue on an actor, but this time it depends 00:15.770 --> 00:20.750 on what our mouse hit actor is and whether it implements the combat interface. 00:20.750 --> 00:26.090 If it does, then we're adding this gameplay cue to the mouse hit actor. 00:26.090 --> 00:29.960 If it doesn't, then we're adding it to the avatar actor instead. 00:30.680 --> 00:36.850 Now, as soon as we've done that, I want to add more cues to more actors. 00:36.860 --> 00:39.700 I want to get more actors that are close by. 00:39.710 --> 00:42.100 I want to store additional targets. 00:42.110 --> 00:49.310 In other words, I want to generate an array of actors and create target gameplay queue parameters for 00:49.310 --> 00:53.600 each one, and apply our electric beam to each one. 00:53.630 --> 01:02.000 Now, compiling an array of actors generally involves loops, and I'm going to get actors that are nearby. 01:02.030 --> 01:04.610 So we're going to be performing some kind of query. 01:04.640 --> 01:06.920 This is all stuff that we should do in C plus plus. 01:06.920 --> 01:09.530 So I'm going to make a C plus plus function. 01:09.680 --> 01:13.760 So saving all I'm going to open Aura Beam spell. 01:13.760 --> 01:16.790 And we'll be making another blueprint callable function. 01:16.790 --> 01:18.080 It's going to be void. 01:18.080 --> 01:22.280 And I'm going to call this store additional targets. 01:22.880 --> 01:27.800 Now I'd like to pass in a T array by reference non-const. 01:27.830 --> 01:30.800 It'll be a t array of a actor pointers. 01:32.240 --> 01:35.750 So passed in by reference, and I'm going to call it out. 01:35.870 --> 01:37.400 Additional target. 01:37.400 --> 01:41.810 So it's an out parameter and it's going to be blueprint callable. 01:44.010 --> 01:44.310 Oops. 01:44.310 --> 01:45.690 Didn't mean to build. 01:45.690 --> 01:47.040 I'm going to cancel that build. 01:47.040 --> 01:49.920 And we're going to generate a definition for this. 01:50.370 --> 01:54.610 So we need to think about what this is going to do for us. 01:54.630 --> 01:58.830 Now I want this function to generate a t array of actors. 01:58.830 --> 02:04.410 And I want them to be nearby actors that implement the combat interface. 02:04.710 --> 02:07.620 On top of that, I want them to not be dead either. 02:07.800 --> 02:12.990 Now, if we go into our ability system blueprint library. 02:14.500 --> 02:20.650 Or ability system library, and we take a look at get live players within radius. 02:20.680 --> 02:23.710 We can take a look at its implementation. 02:25.540 --> 02:29.110 This performs a query with sphere params. 02:29.110 --> 02:30.940 We have a given radius. 02:31.030 --> 02:38.800 We have a check to see if the actors that are overlapping a sphere of the given radius implement the 02:38.800 --> 02:40.180 combat interface. 02:40.210 --> 02:42.190 It even checks to see if they're dead. 02:42.400 --> 02:44.380 If they're not dead. 02:44.410 --> 02:47.770 Then we add them to the out overlapping actors. 02:47.770 --> 02:50.170 So this is the perfect function for us. 02:50.170 --> 02:52.720 So I'd like to call that function. 02:53.020 --> 02:58.060 So I'm going to call you Ora ability System Library. 02:58.930 --> 03:01.600 Get live players within radius. 03:01.630 --> 03:04.840 Now this requires a world context object. 03:04.930 --> 03:07.240 I'm just going to pass in the avatar actor. 03:07.240 --> 03:14.380 So get avatar actor from actor info and we need a t array of actors. 03:14.410 --> 03:17.350 Now I'm not going to pass in out additional targets. 03:17.350 --> 03:20.050 That's going to be what this function returns. 03:20.050 --> 03:26.980 But this function will get us all players, or at least all things that implement the combat interface 03:26.980 --> 03:28.570 within radius. 03:28.570 --> 03:31.030 And that's not what I want. 03:31.060 --> 03:34.750 I only want the first few that are closest. 03:34.750 --> 03:37.570 So we're going to have to call out the closest ones. 03:37.570 --> 03:43.030 So for that reason I'm going to make a local t array of actor pointers. 03:43.840 --> 03:46.870 And this is going to be overlapping actors. 03:48.410 --> 03:50.930 So I'm going to pass in overlapping actors. 03:52.460 --> 03:58.580 Now, in addition to that array, we need to have an array of actors to ignore. 03:58.670 --> 04:00.800 So I'm going to go ahead and make that. 04:01.340 --> 04:07.040 I'm going to copy this array and rename it to Actors to Ignore. 04:07.040 --> 04:13.190 And in fact I'm going to make this first so that overlapping actors is the closest thing to the function 04:13.190 --> 04:13.760 call. 04:13.760 --> 04:19.880 And I'm going to take actors to ignore and add the avatar. 04:19.880 --> 04:22.700 So get avatar actor from actor info. 04:23.210 --> 04:25.910 Now we won't even have to filter that out. 04:26.000 --> 04:31.670 Now, in addition to the avatar actor, I'm going to add the mouse hit actor as well. 04:31.670 --> 04:34.940 So that way we're only getting additional targets. 04:34.970 --> 04:37.520 We don't care about the mouse hit actor anymore. 04:37.550 --> 04:42.650 We're already adding a gameplay cue to that one, so I'm going to take actors to ignore. 04:44.740 --> 04:47.740 And add mouse hit actor. 04:48.970 --> 04:52.660 And with that, I can pass in actors to ignore. 04:53.440 --> 04:53.800 All right. 04:53.800 --> 04:57.880 At this point I'm going to put these inputs on their own lines. 04:58.210 --> 05:01.120 And let's see what our next input needs to be. 05:01.760 --> 05:03.380 It needs to be a radius. 05:03.410 --> 05:10.550 Now it's going to be a pretty big radius, and the aura beam spell could scale the radius with the level. 05:10.550 --> 05:15.650 You know how to do that with curve tables, you could use a mathematical formula. 05:15.680 --> 05:17.630 I'm going to hard code 850. 05:18.020 --> 05:20.840 But you know how to parameterize that. 05:21.050 --> 05:26.120 And for the sphere origin we're going to use the mouse hit actors location. 05:26.120 --> 05:30.440 So mouse hit actor get actor location. 05:33.050 --> 05:40.610 So after calling, this function will have an array of actors that are within 850 units away. 05:40.640 --> 05:46.880 Now we need to get the closest few and or a beam spell should have a maximum for that. 05:46.910 --> 05:52.640 Now, as I mentioned, we're going to be shocking more and more nearby goblins and monsters depending 05:52.640 --> 05:54.350 on the level of this ability. 05:54.350 --> 05:56.390 And we should go up to a max. 05:56.390 --> 06:00.770 So or a beam spell is going to get a max number of shock targets. 06:00.770 --> 06:07.430 So we'll have a variable int 32 max num. 06:07.580 --> 06:12.200 We'll call it shock targets and we'll set it to five. 06:12.860 --> 06:18.650 It could really be anything, but we'll give that a property with edit defaults only. 06:19.730 --> 06:23.690 And of course you property gets a Y at the end. 06:25.050 --> 06:25.560 There we go. 06:25.560 --> 06:27.030 So edit defaults only. 06:27.030 --> 06:30.150 And that'll be in the category of beam as well. 06:30.810 --> 06:32.610 And we'll use that. 06:32.610 --> 06:41.040 And what we'll do in or a beam spell is we'll have an INT 32 called num additional targets. 06:41.460 --> 06:47.760 And we'll use F math and take the minimum between the ability level. 06:47.760 --> 06:52.620 So get ability level and max num shock targets. 06:52.620 --> 06:56.250 And looks like that is missing a parentheses. 06:56.250 --> 06:57.150 There we go. 06:57.540 --> 06:58.080 There. 06:58.080 --> 06:58.800 That's better. 06:58.800 --> 07:03.570 So num additional targets will be whatever ability level we're at. 07:03.660 --> 07:08.130 But of course I'm going to use ability level minus one. 07:08.960 --> 07:14.600 And that way we get the ability level number of beams total up to a maximum. 07:14.600 --> 07:20.960 Now I'm going to comment that out and use this line when we're finished with everything. 07:20.960 --> 07:27.620 But for testing purposes, I'd like to set a max number of five. 07:28.040 --> 07:30.590 So I'm going to call this local num. 07:30.620 --> 07:35.930 Additional targets local variable I'm going to set it to five. 07:37.570 --> 07:41.650 So now that I have overlapping actors, we could have 20 or 30 actors. 07:41.650 --> 07:47.590 We probably won't have that many, but we could have a lot of enemies nearby, and we're going to need 07:47.590 --> 07:54.040 to get the closest few, and we'll need a function to get the closest few. 07:54.070 --> 08:00.610 We can call it get closest targets, and we can make a static function in our ability system library 08:00.610 --> 08:02.350 to get the closest targets. 08:02.440 --> 08:05.770 So that'll be just under get live players within radius. 08:05.770 --> 08:09.190 It'll be static and it'll be void. 08:09.190 --> 08:13.210 And I'm going to call it Get closest Targets. 08:14.410 --> 08:20.680 So we'll have an INT 32 called Max targets. 08:21.010 --> 08:22.900 That's how many targets we need. 08:23.500 --> 08:25.540 We're going to have a const t array. 08:27.310 --> 08:28.210 Of a actor. 08:28.210 --> 08:29.140 Pointers. 08:30.490 --> 08:34.600 We'll pass it in by reference const reference called actors. 08:34.750 --> 08:41.530 And then we'll pass in a non const t array of actors pointers of course. 08:41.920 --> 08:47.260 And we'll pass this one in by non-const reference called out closest targets. 08:47.650 --> 08:52.450 So we'll pass in two arrays one filled with actors and the other will be empty. 08:52.450 --> 08:55.390 And it will have the closest targets. 08:55.420 --> 08:58.270 It'll be this mini Max targets. 09:00.000 --> 09:06.090 And if we're going to calculate the distance from anything, we need to know the distance from what. 09:06.120 --> 09:14.030 So this function gets a const f vector that we can use to calculate the distance from. 09:14.040 --> 09:15.420 We'll call it origin. 09:15.420 --> 09:18.480 So it'll be the origin of this algorithm. 09:18.900 --> 09:21.060 All right let's generate the definition. 09:21.620 --> 09:25.670 Now, how do we get the closest number of targets? 09:25.820 --> 09:29.090 That number being max targets out of an array. 09:29.360 --> 09:38.210 How do we create an array of actors that contains only that number of actors from the actors array? 09:38.420 --> 09:45.950 Assuming that the actors array has more actors than max targets, well, this could be done in a number 09:45.950 --> 09:50.750 of ways, and I'd like to challenge you to give it a shot. 09:50.870 --> 09:56.030 I want you to at least brainstorm and think about how you could possibly do it, and even give it a 09:56.030 --> 09:56.870 try. 09:56.990 --> 10:03.260 So if you're up to that challenge, pause the video now and implement Get closest Targets. 10:07.280 --> 10:10.790 Okay, so how are we going to do this? 10:10.820 --> 10:19.400 Well, first of all, if my actor's array, let's just say it has five actors in it and we pass in seven 10:19.400 --> 10:20.630 for max targets. 10:20.630 --> 10:27.020 Well, actors doesn't have seven, so it already contains the closest actors. 10:27.020 --> 10:29.980 We can't return an array of seven actors. 10:29.990 --> 10:31.490 We have to return actors. 10:31.490 --> 10:32.060 Right. 10:32.090 --> 10:35.840 So actors has to be bigger than max targets. 10:35.840 --> 10:37.760 Otherwise we just return actors. 10:38.430 --> 10:42.480 So we're going to check if actors dot num. 10:43.730 --> 10:49.760 Now if actors num is smaller than or equal to max targets. 10:51.770 --> 10:57.920 Then we can just set out closest targets to actors and return. 10:59.300 --> 11:08.150 There's no point in trying to find the closest max targets targets if actors doesn't even have max targets 11:08.150 --> 11:10.670 in it, so we can return early in that case. 11:11.630 --> 11:18.420 However, if we make it past that now, we need to search through actors for the closest ones. 11:18.440 --> 11:20.330 So here's how I'm going to do it. 11:20.630 --> 11:25.490 I'm first going to make a copy of actors that's not const. 11:25.520 --> 11:28.700 That way I can remove elements from it and things. 11:28.700 --> 11:33.710 So I'm going to make a t array not const of a actor pointers. 11:34.400 --> 11:38.780 And I'm going to call this actors to check and set it equal to actors. 11:38.780 --> 11:40.640 So I'm making a copy of it. 11:41.000 --> 11:46.790 After that I'm going to make a local INT 32 called num targets found. 11:47.000 --> 11:54.560 That way I can keep track as soon as I find an actor that I know is one of the closest ones, then I 11:54.560 --> 12:02.900 can increment this integer, and then I'm going to use a while loop, and I'm going to continue looping 12:02.960 --> 12:08.570 as long as my num targets found is less than max targets. 12:10.520 --> 12:18.560 Now this should work because as long as max targets is greater than the number of actors in our array, 12:18.590 --> 12:20.900 then we'll find enough actors. 12:21.200 --> 12:23.930 If not, we've already returned out of the function. 12:24.740 --> 12:34.160 Now I'm going to make a double called closest distance, and I'm going to keep updating this to the 12:34.160 --> 12:38.060 closest distance that I find as I loop through this array. 12:38.090 --> 12:45.710 And in order to check to see if something is closer than closest distance, I need to start closest 12:45.710 --> 12:48.180 distance off at a really big number. 12:48.200 --> 12:52.070 In fact, I can make it the biggest it can possibly be for a double. 12:52.100 --> 13:00.200 I can use t numeric limits specifying double, and there's a function on this called max, and this 13:00.200 --> 13:03.800 returns the maximum possible value that a double can be. 13:03.890 --> 13:08.320 So that's what I'm starting double off as the biggest it possibly can be. 13:08.330 --> 13:12.320 And after that I'm going to loop through actors to check. 13:13.410 --> 13:16.410 So I know actors to check contains our actors. 13:16.530 --> 13:24.570 So I'm going to say for a actor pointer potential target in actors to check. 13:24.750 --> 13:30.390 So we're looping through every single one and I'm going to calculate the distance. 13:30.510 --> 13:34.320 I'll make a const double distance. 13:35.100 --> 13:41.360 And I'll calculate the distance between the potential target and my origin. 13:41.370 --> 13:49.530 So I'm going to say potential target get actor location minus origin. 13:49.710 --> 13:56.030 I'll get that vector and get its length and store that in distance. 13:56.040 --> 14:01.950 So for each actor in actors to check I'm calculating its distance to the origin. 14:01.950 --> 14:06.150 And I'm going to check to see if that distance is less than closest distance. 14:06.150 --> 14:11.310 So I'm going to say if distance is less than closest distance. 14:12.370 --> 14:12.700 Then. 14:12.700 --> 14:15.430 Now my closest distance is this distance. 14:15.640 --> 14:18.820 So I'll say closest distance equals distance. 14:20.070 --> 14:26.880 And I'm going to make a closest actor that I'm going to set to the potential target here. 14:27.240 --> 14:36.120 So before looping, I'm going to create, along with my closest distance, an a actor called Closest 14:36.120 --> 14:36.900 Actor. 14:38.610 --> 14:48.240 And as I loop through this array of actors to check each time, their distance to the origin is smaller 14:48.240 --> 14:54.150 than my closest distance, I update closest distance and I also update closest actor. 14:54.990 --> 14:59.040 I set it equal to this potential target. 15:01.190 --> 15:10.790 So by the end of this for loop, my closest actor is going to be the closest in this entire array to 15:10.790 --> 15:11.930 the origin. 15:12.230 --> 15:21.290 And by the time I finish my for loop, my closest actor being the closest one can be removed from actors 15:21.290 --> 15:22.130 to check. 15:22.760 --> 15:24.860 So I'll say actors to check. 15:24.980 --> 15:28.040 Dot remove closest actor. 15:28.730 --> 15:33.040 Now, on top of that, though, I need to remember that closest actor. 15:33.050 --> 15:37.430 I'm going to add that into my out closest targets. 15:37.430 --> 15:40.220 So I'm going to say out closest targets. 15:40.220 --> 15:42.080 And I'm going to add unique. 15:42.740 --> 15:46.280 That way we'll never add more than one of the same one. 15:48.340 --> 15:52.030 So now out closest targets gets that closest actor. 15:52.030 --> 15:57.490 And as soon as we've done this I'm going to increment num targets found. 16:00.590 --> 16:03.950 So I'm going to say plus plus num targets found. 16:04.460 --> 16:05.000 Okay. 16:05.000 --> 16:13.820 So what this is going to do is while num targets found is less than max targets, it starts off at zero. 16:13.850 --> 16:16.350 Let's say max targets is five. 16:16.370 --> 16:23.270 So as long as num targets found is less than max targets, this whole loop will keep iterating. 16:23.360 --> 16:26.620 So first it creates a really big double. 16:26.630 --> 16:29.510 It creates a closest actor. 16:29.510 --> 16:34.850 And then we loop over actors to check which is a copy of actors. 16:34.880 --> 16:42.020 We create a const double and set it equal to the length of the vector from the origin to each potential 16:42.020 --> 16:42.680 target. 16:42.710 --> 16:46.520 That's the distance of that potential target to the origin. 16:47.720 --> 16:52.070 If that distance is less than our closest distance, which starts off really big. 16:52.070 --> 16:59.240 So at first it will be, then closest distance becomes that number, closest actor now becomes that 16:59.240 --> 17:00.380 potential target. 17:00.380 --> 17:04.010 And then the for loop goes to the next actor. 17:04.010 --> 17:08.660 And the distance of that actor to the origin is calculated. 17:08.660 --> 17:15.830 If that's even smaller than the closest distance, which was the distance of the first actor, well 17:15.830 --> 17:18.620 then now closest distance is a little bit smaller. 17:18.620 --> 17:23.930 If it's not, then closest distance doesn't get updated and we go to the next actor. 17:23.930 --> 17:27.440 So we're checking all the actors in the array. 17:27.770 --> 17:34.310 But every time we find the closest actor in the whole array, we remove it from the array and add it 17:34.310 --> 17:39.650 to the out parameter array and increment num targets found. 17:39.650 --> 17:41.900 And then the while loop starts over. 17:41.900 --> 17:45.110 And this time actors to check is one less. 17:45.110 --> 17:49.430 And we keep doing this until we've found the number of targets we need. 17:49.670 --> 17:56.870 And of course if actors to check ever becomes empty, well then we can have a safeguard here. 17:56.870 --> 18:05.240 We can say if actors to check dot num equals zero, we can break. 18:05.480 --> 18:07.460 So we can have a safeguard there. 18:07.880 --> 18:12.710 Okay, so here's my algorithm and I'm really excited to see what you came up with. 18:12.710 --> 18:18.830 And I'd like you to share it in the discord and show how much better your algorithm is than mine. 18:18.830 --> 18:22.010 Because there are multiple ways to do this. 18:22.010 --> 18:25.910 And you could get more advanced, you could get more clever. 18:25.910 --> 18:28.430 So I'm interested in seeing what you came up with. 18:28.730 --> 18:35.870 But now that we have get closest targets, we have something that will fill in out closest targets and 18:35.870 --> 18:39.680 we can specify how many of the closest targets we want. 18:39.680 --> 18:44.990 So back in Aura Beam spell we can call this function and store additional targets. 18:45.170 --> 18:49.850 So I'm going to use your aura ability system library. 18:50.150 --> 18:54.740 Get closest targets which needs a max targets. 18:54.740 --> 18:58.820 I'm just going to pass in num additional targets. 18:59.300 --> 19:00.920 That's going to be five. 19:00.920 --> 19:07.220 I'm going to pass in our overlapping actors because we just got all live players within radius. 19:08.870 --> 19:13.160 So we're passing that in as the actors. 19:13.670 --> 19:18.020 Now we need our out parameter out closest targets. 19:18.020 --> 19:20.810 That's going to be out additional targets. 19:20.810 --> 19:24.320 That'll be whatever we pass in to store additional targets here. 19:24.650 --> 19:26.780 And finally we need the origin. 19:26.780 --> 19:32.990 And I'm going to find all actors closest to the mouse hit actor. 19:32.990 --> 19:34.970 So we're going to say mouse hit actor. 19:36.390 --> 19:38.280 Get actor location. 19:40.230 --> 19:46.620 After this out, additional targets will be filled in with the closest five. 19:46.650 --> 19:53.490 If there are five actors that implement the combat interface that are not dead and we can use that. 19:53.490 --> 19:56.280 So I'm going to go ahead and run and debug mode. 19:56.920 --> 20:01.090 And I'd like to just check to make sure that this is working. 20:01.180 --> 20:09.730 We can check by adding a whole bunch of goblins into the world, and then see what this function returns 20:09.730 --> 20:11.650 for us with some debug spheres. 20:13.110 --> 20:15.330 So I'm going to get my ability open. 20:15.330 --> 20:22.410 And as soon as an electrocute, we've added our first gameplay cue. 20:22.440 --> 20:29.220 I'm going to call our new function and hopefully I made it blueprint callable store additional targets. 20:29.490 --> 20:31.440 Yes, it's blueprint callable. 20:31.560 --> 20:37.860 So we're going to call store additional targets and this will return us a T array. 20:38.010 --> 20:41.400 So we'll go ahead and hook both of these up. 20:41.980 --> 20:45.730 And I'd like to create a for each loop. 20:47.670 --> 20:52.860 And each of these is an actor, and I'd like to get its location and show a debug sphere. 20:52.860 --> 20:56.190 So in the loop body draw debug sphere. 20:59.770 --> 21:01.630 We're going to get our array element. 21:01.630 --> 21:03.310 Get actor location. 21:03.880 --> 21:05.940 Hook that into the sphere center. 21:05.950 --> 21:13.840 I'm going to make it red and make the duration 20s and the thickness we'll leave it zero. 21:15.750 --> 21:22.650 And with that, I'd like to create a whole bunch of these goblins and. 21:23.980 --> 21:27.310 We'll see if we get the closest five. 21:27.610 --> 21:30.460 So I'm going to copy each of these a couple times. 21:40.640 --> 21:41.540 Like so. 21:41.960 --> 21:43.340 And. 21:44.000 --> 21:45.260 We'll do a couple more. 21:48.100 --> 21:48.970 There we go. 21:53.660 --> 21:57.290 And with that, I'm going to save all and press play. 21:59.950 --> 22:03.220 Okay, so those spheres are too big. 22:05.950 --> 22:07.420 Let's make the radius. 22:07.420 --> 22:09.340 Oh, I didn't change the radius. 22:09.340 --> 22:11.110 I'm going to make it about 15. 22:12.720 --> 22:19.440 And as soon as I release their one, two, three, four, five we got the five closest. 22:19.440 --> 22:22.950 And this is within an 850 radius. 22:22.950 --> 22:27.360 So we can also draw a single sphere when completed here. 22:28.750 --> 22:33.850 We can draw a white one and this could be a radius of 850. 22:36.490 --> 22:39.550 And we're drawing it at mouse hit location. 22:39.550 --> 22:41.800 That's the location of the mouse hit actor. 22:41.890 --> 22:45.370 So we'll draw that for a duration of 20 as well. 22:45.370 --> 22:48.940 And that'll show us the radius that we're querying here. 22:48.940 --> 22:50.110 It's quite big. 22:50.110 --> 22:55.840 So we're getting the closest five actors to the thing we're shocking. 22:55.840 --> 22:58.720 So right there let's try a different one. 22:58.720 --> 23:00.130 We'll try this one here. 23:01.140 --> 23:02.130 And we're getting those. 23:02.160 --> 23:03.960 Those are the closest five. 23:05.900 --> 23:07.790 And if we try over here. 23:10.200 --> 23:11.770 Those are the closest five. 23:11.790 --> 23:14.460 So our algorithm works. 23:15.810 --> 23:16.500 Okay. 23:16.500 --> 23:22.440 Now that we are getting additional targets, we got those five closest actors. 23:22.470 --> 23:27.600 It's now time to apply some gameplay cues to those actors. 23:27.600 --> 23:31.950 And then we also need to figure out how we can start doing some damage to those actors. 23:31.950 --> 23:33.810 So we're one step closer. 23:33.840 --> 23:36.660 Excellent job, and I'll see you in the next video.