WEBVTT 00:06.970 --> 00:08.080 Welcome back. 00:08.410 --> 00:12.430 So we have the ability to launch fireballs, but we have an issue. 00:12.460 --> 00:15.340 We don't have any way to guide the fireball. 00:15.340 --> 00:18.590 We don't know which direction to send it off in. 00:18.610 --> 00:20.560 If we click over here. 00:21.680 --> 00:24.810 Our fireball still goes off into the distance that way. 00:24.830 --> 00:26.330 So that's a problem. 00:26.420 --> 00:32.320 We also would like a direction to orient the character towards. 00:32.330 --> 00:42.110 So I think that data that we want is basically the data of the hit result under the cursor when we click. 00:42.200 --> 00:47.310 Now we can create an ability task that can get this data for us. 00:47.330 --> 00:54.140 So here in GA Firebolt, as soon as we activate the ability, we could get that hit results under the 00:54.140 --> 01:01.020 cursor or at least the location associated with it and use that here in the ability. 01:01.040 --> 01:07.700 So we're going to make an ability task that can get that data for us and then we're going to see how 01:07.700 --> 01:13.670 this works in multiplayer and whether or not we need to make some changes to make this work for a multiplayer 01:13.700 --> 01:14.360 game. 01:14.600 --> 01:18.020 So first we're going to make a new ability task class. 01:18.050 --> 01:22.260 I'm going to go ahead and close out of some of these tabs. 01:22.260 --> 01:27.270 I think I'll go ahead and leave the Firebolt open and we'll go into C plus plus classes. 01:27.300 --> 01:29.550 Aura, public ability system. 01:29.700 --> 01:31.770 And we'll make a class right here. 01:31.890 --> 01:37.500 And I'm going to select all classes and search for ability task. 01:38.040 --> 01:45.300 So here we have ability task notice it's based on the gameplay task class and also notice that the engine 01:45.300 --> 01:48.830 has a number of ability tasks already built in. 01:48.840 --> 01:57.690 So we're going to make our own and I'm going to put this in ability system slash ability tasks and I'm 01:57.690 --> 02:03.120 going to name this target data under mouse. 02:03.120 --> 02:10.110 So this ability task will be concerned with getting data related to that hit results under the mouse 02:10.110 --> 02:10.950 cursor. 02:10.980 --> 02:18.390 Now notice we're calling this target data under mouse and gas target data means something specific. 02:18.390 --> 02:23.430 So this is a foreshadowing to a topic that we're going to get into very shortly. 02:23.430 --> 02:26.820 But for now, let's just create our ability task. 02:27.030 --> 02:33.780 I'm going to go ahead and close the editor and we'll let Ryder populate these folders here. 02:33.780 --> 02:39.760 And I'm going to keep Aura Projectile spell open, but I'm going to open target data under Mouse. 02:39.760 --> 02:42.580 There's the CP and here's the header file. 02:42.700 --> 02:43.450 Okay. 02:43.450 --> 02:50.980 Now we already took a look at play montage and wait and we saw that it had this static function that 02:50.980 --> 02:55.210 created an instance of this particular class and returned it. 02:55.330 --> 02:57.700 We're going to follow that pattern here. 02:57.700 --> 03:01.630 So for target data under Mouse, we're going to make a static function. 03:01.630 --> 03:03.040 It's going to be public. 03:03.040 --> 03:10.420 So here's our public section and we're going to make a static function that returns a new target data 03:10.450 --> 03:12.370 under mouse pointer. 03:12.370 --> 03:19.120 So we're going to call this function create target data under mouse. 03:19.660 --> 03:28.180 Now this function is going to receive the owning gameplay ability and that's pretty typical for these 03:28.180 --> 03:31.510 ability tasks they take in a new gameplay ability. 03:33.140 --> 03:34.730 And that's a pointer. 03:34.730 --> 03:37.070 And we call this owning ability. 03:37.190 --> 03:45.140 And whenever we call this function from within a gameplay ability, this owning ability parameter, 03:45.140 --> 03:50.470 we would like passed in by default and we would like it to be the self. 03:50.480 --> 03:52.730 In other words, the this pointer. 03:52.730 --> 03:54.530 But in blueprint it's called self. 03:54.530 --> 03:59.660 That's the current ability that's running this gameplay task. 03:59.660 --> 04:05.660 So we're going to have a new function macro with a number of specifiers here. 04:05.900 --> 04:08.960 So for one, it's going to be blueprint callable. 04:09.140 --> 04:11.750 Two, it's going to have a category. 04:11.750 --> 04:17.480 And for the category we're going to put it in ability pipe symbol tasks. 04:17.480 --> 04:19.250 So it's an ability task. 04:19.700 --> 04:27.620 Now in order to make this owning ability default to the self, we're going to use the meta specifiers. 04:28.790 --> 04:35.300 So meta equals and a new set of parentheses and we're going to default to self, but we're also going 04:35.300 --> 04:43.550 to hide the pin for owning ability so we can use hide pin equals and we specify owning ability. 04:45.120 --> 04:50.550 We also use default to self specifying owning ability. 04:51.700 --> 04:56.470 So by default it'll be defaulted to the self. 04:56.740 --> 05:00.470 And this function is internal. 05:00.490 --> 05:00.910 Right. 05:00.910 --> 05:07.050 We're exposing this to the event graph, but this is a special internal function. 05:07.060 --> 05:12.220 It's really just a factory that creates an instance of this task and returns it. 05:12.370 --> 05:19.870 So what we're going to do in the meta parentheses here is we're going to say blueprint internal use 05:19.870 --> 05:22.480 only equals true. 05:22.930 --> 05:26.860 Now, this is called create target data under mouse. 05:26.920 --> 05:34.060 If we want our blueprint node to have a different name, we can use a display name here in the meta 05:34.060 --> 05:35.080 parentheses. 05:35.110 --> 05:36.130 Let's go ahead and do that. 05:36.130 --> 05:38.680 Let's say display name. 05:40.550 --> 05:48.770 And that'll be equal to I'll put a comma after the quotes and we'll say target data under mouse. 05:49.070 --> 05:51.320 So now there will be a display name as well. 05:51.350 --> 05:54.290 So lots of new function specifiers here. 05:54.320 --> 05:56.090 That's pretty typical for these. 05:56.390 --> 05:59.960 So let's go ahead and implement the function. 06:00.700 --> 06:02.620 Create a definition for it here. 06:03.250 --> 06:06.010 And here's what we typically do. 06:06.040 --> 06:10.480 We create a new object of type U target data under mouse. 06:10.570 --> 06:12.610 So I'm going to copy this. 06:12.700 --> 06:16.510 Type paste it there and we can call it anything. 06:16.510 --> 06:18.190 It's a local pointer variable. 06:18.190 --> 06:26.380 We're going to call this my obj for object and to create a new ability task, we use new ability task. 06:26.410 --> 06:27.520 It's a template. 06:27.520 --> 06:28.870 It requires the type. 06:28.870 --> 06:32.200 We're going to make a new target data under mouse. 06:32.500 --> 06:40.390 And when we create a new one of these, it's going to require the gameplay ability that owns it. 06:40.390 --> 06:42.990 So we pass in the owning ability here. 06:43.000 --> 06:45.250 Now the name is optional. 06:45.250 --> 06:48.730 It defaults to an empty F name, so we're just going to leave it out. 06:48.730 --> 06:56.230 And now that we've created a new object, we can simply return it here, return my obj. 06:56.500 --> 07:04.430 Now, if we wanted to, we could set any number of variables on our target data under mouse and we could 07:04.430 --> 07:11.690 make this function here, take in any number of input parameters and we could get those passed in from 07:11.690 --> 07:17.540 the blueprint node and we can set those values right here on this object. 07:17.660 --> 07:21.830 I'm just going to have none so we can see what this looks like. 07:21.830 --> 07:25.910 If we attempt to create one of these from within our ability. 07:26.000 --> 07:32.150 So why don't we go ahead and compile and launch the editor and try to create a target data under mouse 07:32.150 --> 07:34.700 node in our gameplay ability? 07:36.670 --> 07:42.370 Okay, so let's get that game play ability open and right at the beginning, as soon as we activate 07:42.370 --> 07:52.240 the ability, I'm going to right click right here and type in target data under mouse, it's under ability 07:52.270 --> 07:53.320 tasks. 07:53.320 --> 07:54.160 So here it is. 07:54.160 --> 07:57.930 Let's click on that and it's pretty bare, right? 07:57.940 --> 08:00.010 But notice it has the little clock right there. 08:00.010 --> 08:03.940 That means it's a latent node or an asynchronous node. 08:04.060 --> 08:12.880 Now all it does so far is just return the instance of the target data under mouse object. 08:12.880 --> 08:14.020 That's all it does. 08:14.020 --> 08:16.510 And we can't really do much with that, can we? 08:16.510 --> 08:18.670 Because it's a pretty empty class. 08:18.700 --> 08:21.910 We can get its name, we can call get object name. 08:22.690 --> 08:24.800 And we can print it to the screen. 08:24.820 --> 08:27.830 That's pretty much the only thing we can do. 08:27.850 --> 08:29.930 So let's just do it. 08:29.950 --> 08:35.110 Print string, passing in that name, and let's go ahead and just click. 08:35.110 --> 08:38.110 And it's a target data under mouse object. 08:38.620 --> 08:40.590 Okay, so that's pretty boring. 08:40.600 --> 08:43.210 But what is this task supposed to do? 08:43.240 --> 08:46.180 It's supposed to get the target data under the mouse, right? 08:46.180 --> 08:48.100 So I'll go ahead and hook that up. 08:48.100 --> 08:50.620 But we need this to return something. 08:50.620 --> 08:53.230 We need it to get some data. 08:53.350 --> 08:55.690 So let's continue our work on this. 08:55.690 --> 09:03.340 I'm going to close and save all, and this is now an asynchronous blueprint node, which means it can 09:03.340 --> 09:06.370 have multiple output execution pins. 09:06.370 --> 09:12.490 And the way that we create those multiple output execution pins is by broadcasting delegates. 09:12.490 --> 09:19.480 So any output execution pin needs to exist as a delegate variable on this class. 09:19.480 --> 09:23.980 So we can create a new delegate, we can declare one up here. 09:23.990 --> 09:25.970 So I'm going to declare one. 09:25.970 --> 09:31.910 I'm going to use declare dynamic multicast. 09:33.440 --> 09:42.860 Delegate and I'm going to use one param because I'd like to broadcast the value of the mouse cursor 09:42.860 --> 09:43.730 location. 09:43.730 --> 09:45.050 Just an f vector. 09:45.050 --> 09:45.830 Why not? 09:46.010 --> 09:52.700 I'm going to call this delegate f mouse target data delegate. 09:52.730 --> 10:02.000 We could also call it actually signature for the type and we're going to have it broadcast a const F 10:02.000 --> 10:07.250 vector called data and we'll make a variable of this type. 10:07.250 --> 10:13.040 It's going to be right here in the public section and we're going to call it valid data, and we'll 10:13.040 --> 10:16.370 make this a new property with blueprint. 10:16.370 --> 10:19.850 Assignable, not blueprint callable blueprint, assignable. 10:19.850 --> 10:25.520 And this will now become an output execution pin on the node. 10:25.760 --> 10:29.990 So now that we have this delegate, let's just compile and run the engine. 10:29.990 --> 10:32.510 I want to see how this changes the node. 10:33.510 --> 10:35.880 And it looks like I have a typo. 10:35.910 --> 10:38.070 I forgot a comma. 10:38.070 --> 10:43.810 So these types need to be separated from the name of that parameter with a comma. 10:43.830 --> 10:45.840 For dynamic multicast delegates. 10:45.870 --> 10:48.390 Okay, now let's compile and launch. 10:49.890 --> 10:50.430 Okay. 10:50.430 --> 10:52.050 Opening our ability. 10:52.080 --> 10:53.610 Now look at this. 10:53.640 --> 11:01.440 Not only does our node have more stuff on it, it has a valid data and it also has this data which is 11:01.440 --> 11:02.460 an F vector. 11:02.460 --> 11:04.500 It's a vector type by reference. 11:04.530 --> 11:05.580 Perfect. 11:05.610 --> 11:08.100 Now, this is never going to be executed. 11:08.100 --> 11:08.460 Why? 11:08.490 --> 11:14.190 Because the only way to execute this is to broadcast this delegate. 11:14.190 --> 11:16.110 That's how these get executed. 11:16.110 --> 11:17.310 Kind of cool, right? 11:17.370 --> 11:25.500 So why don't we broadcast a value As soon as we broadcast valid data, then data will have some valid 11:25.500 --> 11:26.100 data. 11:26.130 --> 11:34.860 So the last thing I'd like to do in this video is for valid data to be broadcast and for data to give 11:34.860 --> 11:37.170 me the location under the mouse. 11:37.290 --> 11:39.810 Now I'm going to close the editor saving all. 11:39.810 --> 11:47.910 And in order to do that, we have to override the ability tasks, activate function, and as soon as 11:47.910 --> 11:52.330 this node is executed, ID activate will be called. 11:52.360 --> 11:57.280 Now this is a private function, so we'll make a private section and this is virtual. 11:57.280 --> 12:01.810 We're going to say virtual void activate override. 12:01.900 --> 12:10.030 And here in Activate, let's generate the definition and we don't have to call super Activate because 12:10.030 --> 12:16.780 if we did that would call the ability tasks activate and if we go to the ability task by the way here's 12:16.780 --> 12:18.580 the new ability task. 12:19.030 --> 12:20.770 If we find activate. 12:22.270 --> 12:24.490 If we search for it, it won't be there. 12:24.490 --> 12:28.840 But if we go all the way into the gameplay task class. 12:31.910 --> 12:34.520 Here's virtual void activate. 12:34.550 --> 12:39.680 So as you can see, it's not even overridden in ability task. 12:39.710 --> 12:48.980 Now here in gameplay task CP if we search for Activate, we'll see here that it just does you vlog. 12:49.010 --> 12:49.970 Vlog. 12:50.120 --> 12:53.210 Basically performing a log and nothing else. 12:53.210 --> 12:55.220 So we really we don't care about that. 12:55.250 --> 12:59.030 Go ahead and call super if you want to, but it's not going to do much. 12:59.030 --> 13:01.160 So I'm going to close gameplay task. 13:01.190 --> 13:06.170 I'm going to close ability task and back to our class here is Activate. 13:06.650 --> 13:12.680 Now we just want to get data and broadcast our delegate valid data. 13:12.680 --> 13:19.280 So once we get the mouse hit location under the mouse and broadcast it, then we can go back into our 13:19.280 --> 13:24.050 blueprint and see if it's working by drawing a debug sphere or something like that. 13:24.050 --> 13:26.930 So this is going to be your quest. 13:27.440 --> 13:31.440 I'd like you to get that valid data and broadcast it. 13:31.440 --> 13:36.420 So this is going to involve getting the location under the mouse cursor. 13:36.450 --> 13:38.790 There should be something you know how to do. 13:38.790 --> 13:46.920 And once you get that broadcast, that valid data delegate and from within your ability, get that data 13:46.920 --> 13:50.040 and draw the debug sphere at the location. 13:50.040 --> 13:52.920 So do that from within our firebolt ability. 13:53.100 --> 13:56.580 So pause the video and conquer this quest now. 13:59.270 --> 14:00.050 All right. 14:00.050 --> 14:05.660 So from here in Activate, we need to figure out how to get that player controller. 14:05.690 --> 14:08.930 That's how we get the hit results under the mouse cursor. 14:09.230 --> 14:14.870 So we need to figure out how we can get that from within the activate function. 14:14.870 --> 14:21.770 So this might have been a bit of a stumping point for you, but remember, ability tasks know which 14:21.800 --> 14:23.750 ability they belong to. 14:23.870 --> 14:33.650 In fact, they have an ability member variable and from ability we can access the actor info with get 14:33.650 --> 14:36.320 current actor info. 14:36.590 --> 14:44.720 Now get current actor info returns gameplay ability actor info and that has a number of variables on 14:44.720 --> 14:48.860 it, including the player controller so we can get it from that. 14:48.890 --> 14:56.780 Now the player controller here is a weak object pointer, so we're going to need to call, get on that. 14:56.780 --> 15:03.570 So this is how we can get the player controller and we can store this in an a player controller pointer. 15:03.960 --> 15:05.580 And I'm just going to call it PC. 15:06.060 --> 15:11.010 Now we can call get hit result on the cursor, which takes an F hit result. 15:11.010 --> 15:17.730 So this will be called, we'll call it cursor hit and we'll take the player controller and call get 15:17.760 --> 15:23.010 hit Results under cursor specifying a E collision channel. 15:23.760 --> 15:26.040 I'm just going to trace against visibility. 15:26.070 --> 15:28.380 We're going to not trace complex. 15:28.380 --> 15:32.940 We're going to trace only against simple collision and pass in that cursor hit. 15:33.570 --> 15:36.360 So now we should have a hit result. 15:36.390 --> 15:42.870 So now all that's left is to broadcast that data, the location of this hit result. 15:43.020 --> 15:52.350 And our delegate is valid data so we can call broadcast on it using our cursor hit dot location or impact 15:52.350 --> 15:53.010 point. 15:53.340 --> 15:54.900 Either of those will work. 15:55.050 --> 16:01.950 So as soon as we activate this ability, then we're going to broadcast that delegate, which means that 16:01.950 --> 16:06.110 valid data execution pin will be executed. 16:06.120 --> 16:13.320 So it just so happens that as soon as we activate the ability, that valid data pin will be executed. 16:13.320 --> 16:15.490 But it doesn't have to be right away. 16:15.510 --> 16:17.220 This is an asynchronous task. 16:17.220 --> 16:24.160 So depending on the gameplay mechanics for some ability tasks we may wish to broadcast those delegates 16:24.190 --> 16:25.450 later in time. 16:25.660 --> 16:28.680 But for this case, we're broadcasting right away. 16:28.690 --> 16:30.610 So let's run in debug mode. 16:33.740 --> 16:36.260 And we'll open up our ability. 16:36.290 --> 16:43.490 Here's target data under mouse and we know that as soon as we reach this node, activate will be called 16:43.490 --> 16:46.190 and valid data will be broadcast right away. 16:46.190 --> 16:48.470 So we're not going to use this node. 16:48.470 --> 16:54.260 We're going to use valid data because as soon as valid data is broadcast, then we should have some 16:54.260 --> 16:57.260 valid data in that data vector. 16:57.260 --> 17:03.230 So I'm going to draw a debug sphere or debug box or anything else really, right? 17:03.410 --> 17:04.850 I'm going to do a sphere. 17:07.340 --> 17:12.950 So I'm going to move these up out of the way and we're going to draw it at the location of data. 17:13.800 --> 17:17.070 I'll give it a radius of 100 line color white. 17:17.070 --> 17:17.790 That's fine. 17:17.790 --> 17:18.420 For duration. 17:18.420 --> 17:23.430 I'll give it 20s and we can test this out. 17:24.650 --> 17:25.160 All right. 17:25.160 --> 17:27.620 Saving all pressing play. 17:27.650 --> 17:28.730 Clicking. 17:29.370 --> 17:32.700 And actually, I have to click on an enemy, right? 17:33.320 --> 17:35.180 In order to activate it. 17:35.180 --> 17:39.560 And I can only activate it once unless I end the ability. 17:43.070 --> 17:46.400 Now I can activate it as many times as I want. 17:47.060 --> 17:50.630 And as long as I'm hovering over an enemy, then boom. 17:52.220 --> 17:55.580 We're getting our target data, so this is great. 17:55.580 --> 18:01.430 But remember, we mentioned we're going to see its limitations, particularly when it comes to multiplayer. 18:01.490 --> 18:07.100 So if I increase the number of players to two and press play, let's see what happens. 18:07.100 --> 18:12.620 If I do this on a client, I'm going to click and look at this on the client. 18:12.620 --> 18:14.270 I clicked way over here. 18:14.270 --> 18:21.500 It's probably hard to see, but I clicked way over here on an enemy and I got my debug sphere in the 18:21.500 --> 18:22.460 correct location. 18:22.460 --> 18:28.460 I can do it for all of these enemies here and it looks great on the client locally, but look at the 18:28.460 --> 18:30.170 server on the server. 18:30.170 --> 18:36.770 It's just showing the debug sphere right here for some reason and I have the sneaking suspicion that 18:36.770 --> 18:43.310 that is the world origin and that would mean that data just has all zeros in it. 18:43.340 --> 18:45.050 It's not being set. 18:45.320 --> 18:47.720 So that's a problem right now. 18:47.720 --> 18:53.550 It makes sense that the server wouldn't know where we're clicking because that's something we're doing 18:53.550 --> 18:54.420 locally. 18:54.450 --> 18:59.250 That's something we're doing here on the client and only the client knows where its mouse cursor is 18:59.250 --> 19:03.090 because that's not data that's being sent up to the server. 19:03.540 --> 19:09.420 If we want the server to know where we're clicking, we have to tell the server where we're clicking. 19:09.420 --> 19:14.250 And so that's going to involve more concepts that we have to learn. 19:14.370 --> 19:22.710 So we've seen the limitations of our new ability task and how yes, we can get valid data and yes, 19:22.710 --> 19:29.550 we can draw a debug sphere for it locally, but the server does not have valid data. 19:29.550 --> 19:33.630 It's not getting that specific piece of information. 19:33.630 --> 19:34.380 Right. 19:34.380 --> 19:36.870 So a couple things are happening here. 19:36.870 --> 19:44.280 Activate ability is being executed locally on the client and because abilities are replicated, then 19:44.280 --> 19:47.880 activate ability is being called on the server as well. 19:48.060 --> 19:55.560 But on the server we're getting this delegate broadcast even though we don't really know where that 19:55.560 --> 19:56.940 mouse cursor is. 19:57.210 --> 20:05.220 So our next steps are to figure out how we can get data from the client up to the server. 20:05.220 --> 20:10.440 And specifically we want that mouse cursor location sent up to the server. 20:10.440 --> 20:14.990 How do we do that and how do we do it in a way that will work reliably? 20:15.000 --> 20:16.940 That's what we're going to do next. 20:16.950 --> 20:18.330 So I'll see you soon.