WEBVTT 00:07.240 --> 00:08.330 Welcome back. 00:08.350 --> 00:13.270 So now that we're calculating the spread, we're ready to spawn some projectiles. 00:13.480 --> 00:20.070 But we're kind of repeating ourselves here as well as in or a summon ability here. 00:20.080 --> 00:26.290 In fact, we've discovered a shortcoming of this algorithm and improved it here in Aura Firebolt. 00:26.320 --> 00:33.430 And now that we have the formula perfected, it's probably a good idea to add a function for this in 00:33.430 --> 00:34.840 a function library. 00:35.140 --> 00:43.750 You see, needing some randomly spread rotators is actually kind of a common thing, and it would be 00:43.750 --> 00:47.110 useful to have just a function on deck for that. 00:47.110 --> 00:53.020 So I'd like to just put one of these into our ability system blueprint library. 00:54.220 --> 00:56.350 Aura ability system library. 00:57.360 --> 01:00.180 And this can be a static function. 01:01.150 --> 01:06.010 It can return a t array of f rotators. 01:08.300 --> 01:12.400 And we can get evenly spaced rotators about some spread. 01:12.410 --> 01:16.100 So we can call this evenly spaced rotators. 01:17.960 --> 01:24.480 And really all it needs is a forward vector and perhaps an axis of rotation. 01:24.500 --> 01:32.630 If we want this to be really versatile so we can pass in a const f vector by reference called forward 01:32.840 --> 01:39.170 and a const f vector by reference called axis. 01:39.560 --> 01:41.210 And we'll have our function. 01:41.210 --> 01:43.820 Now this gives us a t array of rotators. 01:43.820 --> 01:45.980 But what if we wanted them in vector form. 01:45.980 --> 01:47.660 We can make a vector version of it. 01:47.660 --> 01:54.500 So we can make a static function that returns a t array of f vectors. 01:55.280 --> 02:00.710 And we can call this evenly rotated vectors or something like that. 02:01.430 --> 02:04.340 Evenly rotated rotators is a funny name. 02:04.340 --> 02:09.920 I'm going to leave this at evenly spaced rotators, and we'll have evenly rotated vectors, and it'll 02:09.920 --> 02:11.210 take the same inputs. 02:12.890 --> 02:14.870 Now this could be a blueprint pure function. 02:14.870 --> 02:17.570 So I'll go ahead and give it a new function. 02:19.420 --> 02:21.760 And it's going to be. 02:22.060 --> 02:23.500 It could be in gameplay mechanics. 02:23.500 --> 02:24.370 That's fine. 02:25.470 --> 02:26.670 As the category. 02:26.670 --> 02:30.290 So both of these will be blueprint pure. 02:30.300 --> 02:33.810 I'm going to go ahead and generate the functions. 02:33.810 --> 02:37.320 And we already have the algorithm. 02:37.320 --> 02:40.830 We just need to get it from a Firebolt. 02:40.860 --> 02:44.670 So first thing we do is calculate our left of spread. 02:46.150 --> 02:50.620 So we're going to get that line and paste it here. 02:50.860 --> 02:54.160 But we need to know how much to spread. 02:54.160 --> 02:58.350 So these functions also need a spread angle right. 02:58.420 --> 03:00.640 So let's add that as well. 03:00.850 --> 03:03.940 We'll make a float called spread. 03:07.300 --> 03:10.390 That will be passed in to both of them. 03:13.590 --> 03:22.020 So we got left of spread and it's rotating our forward vector by half of spread about the up vector. 03:22.020 --> 03:23.760 But of course we're passing an axis. 03:23.760 --> 03:28.080 So if we wanted to we could pass in something other than the up vector. 03:28.080 --> 03:30.900 So that makes this a little bit more versatile. 03:31.110 --> 03:36.000 Now the next step after we have left of spread is we do a for loop right. 03:36.000 --> 03:37.980 So let's get this for loop here. 03:38.930 --> 03:41.000 Including that delta spread. 03:43.200 --> 03:46.920 So delta spread is going to take the overall spread. 03:48.440 --> 03:53.060 And divide by the number of rotators that we want. 03:53.210 --> 03:57.250 In other words, we need to pass in an integer here. 03:57.260 --> 03:59.990 So we're going to go ahead and do that. 04:00.140 --> 04:05.420 We'll have a int 32 called num rotators. 04:07.340 --> 04:12.350 But our vector version will take an int 32 called num vectors. 04:13.400 --> 04:15.290 So let's go ahead and add these. 04:18.420 --> 04:24.060 So we get numb rotators and this version gets an int 32 numb vectors. 04:25.420 --> 04:28.600 And I totally put this in the wrong place. 04:28.630 --> 04:33.960 This num rotators goes here and evenly spaced rotators. 04:33.970 --> 04:37.180 And then this num vector doesn't even go here. 04:37.210 --> 04:39.740 I'm going to cut it and put it where it belongs there. 04:39.760 --> 04:41.620 Now we should be fine. 04:42.010 --> 04:44.440 And we don't need num rotators there. 04:45.960 --> 04:50.700 Okay, so instead of numb projectiles we now have numb rotators. 04:50.700 --> 04:52.020 We're going to use that. 04:52.050 --> 04:56.820 Now we do need to make sure that numb rotators isn't one. 04:56.820 --> 04:59.760 If numb rotators is one, well that's easy. 05:00.900 --> 05:09.960 We can check if numb rotators is greater than one, then we'll do all this. 05:09.960 --> 05:15.630 So we'll put this stuff in there and we'll have the else case. 05:16.600 --> 05:17.410 Else. 05:17.970 --> 05:21.960 And in this case we have only one rotator to provide. 05:21.960 --> 05:27.300 And that's really just going to be the forward vector converted to a rotator. 05:27.480 --> 05:32.340 So we'll just have a T array of F rotators declared at the top. 05:32.340 --> 05:34.910 That will be for us to return. 05:34.920 --> 05:37.740 We'll call this rotators. 05:38.420 --> 05:42.170 Why is IntelliSense offering me this? 05:42.800 --> 05:45.210 Potential name rotators. 05:45.260 --> 05:48.830 It sounds like a variable name that Gollum would come up with. 05:49.550 --> 05:51.200 I'm going to call it rotators. 05:51.200 --> 06:00.110 So in the case rotators is going to be added to and we'll add forward into it forward rotation. 06:00.110 --> 06:05.510 That is now that's not working because I see up here we have rotators. 06:05.510 --> 06:09.050 That should be a T array of F rotator okay. 06:09.050 --> 06:15.260 So now if num rotators is greater than one then we have delta spread. 06:15.290 --> 06:19.130 We calculate that and then we loop. 06:19.130 --> 06:21.770 We loop over the number of rotators. 06:21.770 --> 06:23.840 So this will be num rotators. 06:23.840 --> 06:26.780 And we'll calculate it a direction. 06:26.900 --> 06:34.670 And that direction is going to be rotated by delta spread times I we don't need to draw a debug arrow 06:34.670 --> 06:36.590 and we don't need a start vector. 06:36.620 --> 06:41.750 All we need to do is take rotators and add to it. 06:41.780 --> 06:43.310 What are we adding? 06:43.550 --> 06:45.630 Direction rotation. 06:46.200 --> 06:49.130 And by the end of this we can return rotators. 06:49.720 --> 06:53.980 And looks like my typo is worse than I thought. 06:54.010 --> 06:56.980 I called this rotators. 06:57.250 --> 06:58.750 Oh, it's all the way back here. 06:58.780 --> 06:59.650 Oh, boy. 07:00.760 --> 07:02.410 All right, that fixes it. 07:02.830 --> 07:05.050 And now we have evenly spaced rotators. 07:05.050 --> 07:13.060 Now this is very much going to be similar for evenly spaced or evenly rotated vectors only we're going 07:13.060 --> 07:16.180 to make a t array of f vector called vectors. 07:16.840 --> 07:21.490 And we're still going to make a left of spread from the forward. 07:21.490 --> 07:30.010 And if num vectors is greater than one, then we create that delta spread using num vectors, looping 07:30.010 --> 07:31.630 over num vectors. 07:31.630 --> 07:38.440 And we take our direction, we rotate it, and then we take our vectors and add direction to it without 07:38.440 --> 07:39.940 converting to a rotator. 07:39.940 --> 07:43.300 So it's the same function without that extra step. 07:43.300 --> 07:46.420 And down here we're going to take vectors. 07:47.750 --> 07:49.160 And just add foreword. 07:49.160 --> 07:53.540 If we only have one and then we return vectors at the very end. 07:54.020 --> 07:58.460 Okay, so we now have two nice utility functions. 07:58.460 --> 08:03.950 And here in Aura Firebolt all we need to do is get those vectors. 08:03.950 --> 08:08.480 We have a number of rotated vectors we can get from this. 08:08.480 --> 08:14.900 So what I'd like to do is not even bother with left of spread and right of spread right. 08:14.900 --> 08:16.790 And all of this stuff. 08:16.790 --> 08:27.230 We can just make a single function call you or a ability system library evenly rotated vectors passing 08:27.230 --> 08:28.340 in forward. 08:28.850 --> 08:32.270 Our axis can be f vector up vector. 08:32.450 --> 08:42.890 Our spread is going to be projectile spread, and num vectors is going to be num projectiles. 08:44.240 --> 08:45.950 And now we have a tray. 08:48.350 --> 08:49.520 Of vectors. 08:50.450 --> 08:52.430 And we'll call this directions. 08:53.180 --> 08:55.520 And why did I write vectors. 08:56.330 --> 09:00.520 So now we have a 2D array of vectors for the directions. 09:00.530 --> 09:08.240 And it would be wise to just make sure that our function does what it's supposed to do by simply looping 09:08.240 --> 09:09.080 over directions. 09:09.080 --> 09:10.550 So we can say for. 09:11.630 --> 09:12.800 F vector. 09:13.530 --> 09:14.420 Ref. 09:15.210 --> 09:18.270 Direction and directions. 09:19.290 --> 09:21.570 And then we can just use this. 09:21.690 --> 09:24.540 Function call for draw debug arrow. 09:24.810 --> 09:30.300 And we're going to use the start location socket location. 09:30.510 --> 09:37.320 And the end location is going to be direction times 75 with all those parameters. 09:37.320 --> 09:39.720 And the rest of this can be commented out. 09:45.240 --> 09:48.740 And we can just make sure evenly rotated vectors works. 09:48.750 --> 09:56.880 And while we're at it, it would probably be a good idea to do the same thing with the rotator version. 09:56.880 --> 09:59.640 So I'm going to make a t array of F rotator. 10:00.330 --> 10:04.860 Didn't say rotators because it would make me type it as rotators. 10:04.860 --> 10:16.230 And I'm going to call this rotations and use you or ability system library evenly spaced rotators passing 10:16.230 --> 10:19.890 in forward f vector up. 10:24.230 --> 10:34.700 Up vector, projectile spread and numb projectiles and we'll just loop over rotations as well. 10:35.000 --> 10:38.300 So this will be for each rotator. 10:38.630 --> 10:41.990 We'll call it rotation I'll just call it root. 10:42.830 --> 10:47.330 We have a rotation up there looping through rotations. 10:47.330 --> 10:53.330 And then our socket location will be root dot vector times 75. 10:53.330 --> 10:56.600 Let's just run this and make sure both of these work. 10:56.600 --> 11:04.130 And actually before we test this I want to draw the rotation one in blue and slightly raised. 11:04.130 --> 11:15.290 So I'm going to make an f vector start socket location plus f vector 005. 11:16.610 --> 11:19.010 And we'll replace socket location with start. 11:19.040 --> 11:20.300 Now let's try. 11:21.830 --> 11:22.220 All right. 11:22.220 --> 11:23.720 We'll get the ability open. 11:23.720 --> 11:24.050 We'll see. 11:24.050 --> 11:26.000 We have five projectiles. 11:26.030 --> 11:28.340 Our spread is 90 degrees. 11:30.290 --> 11:31.280 There we go. 11:31.310 --> 11:34.790 Looks like both of our algorithms work just fine. 11:34.970 --> 11:36.620 There's the rotator version. 11:36.620 --> 11:38.290 There's the vector version. 11:38.300 --> 11:40.320 We have two to choose from. 11:40.340 --> 11:41.210 Perfect. 11:41.240 --> 11:46.220 All right, so now that we know those are working, we don't need all this debug stuff do we. 11:46.310 --> 11:50.600 So I'm going to go ahead and remove the debug stuff. 11:50.600 --> 11:52.040 All of this. 11:52.910 --> 11:55.960 I'm done with it I know my functions work. 11:55.970 --> 11:59.260 Now what I need to do is pick one of these. 11:59.270 --> 12:00.650 So I'm going to pick one of these. 12:00.650 --> 12:03.310 And the one I'm going to pick is rotations. 12:03.320 --> 12:06.350 So I have a t array of rotations. 12:06.350 --> 12:09.740 And that just goes back to our aura projectile spell. 12:09.740 --> 12:15.170 When we set a transform for the projectile we spawn we already have the location. 12:15.170 --> 12:17.420 We just need to set the rotation for it. 12:17.420 --> 12:21.530 And so for that simple reason I'm going to use rotations. 12:21.530 --> 12:26.270 I'm going to use a for loop and loop over rotations. 12:26.270 --> 12:32.960 We'll make a const f rotator reference for each iteration we'll call it rotation. 12:32.960 --> 12:37.010 We'll just call it root looping over rotations. 12:37.010 --> 12:40.130 And we want to spawn projectiles. 12:40.130 --> 12:42.590 So let's look at our projectile spell. 12:42.590 --> 12:50.450 We'll see that we have spawn transform made from socket location and rotation dot quaternion. 12:50.450 --> 12:54.170 Let's copy that and put it in our for loop only. 12:54.170 --> 12:57.080 Instead of rotation we're going to use root. 12:57.290 --> 13:02.690 And now that we have spawn transform we can go about spawning a projectile. 13:02.690 --> 13:11.660 And for now I'm just going to use the same code that we used in our projectile spell, namely just spawning 13:11.660 --> 13:15.200 a projectile of this type A or a projectile. 13:15.290 --> 13:17.660 I'll go ahead and include its type here. 13:21.550 --> 13:23.470 I'm going to steal it from. 13:23.470 --> 13:25.030 Or a projectile spell. 13:25.060 --> 13:26.050 There it is. 13:27.390 --> 13:33.530 It looks like I don't need gameplay tags there and back in aura Firebolts since I don't need Kismet 13:33.530 --> 13:35.030 System library. 13:35.180 --> 13:41.900 I'm going to replace it with Aura Projectile and I'm also going to collapse get description and next 13:41.900 --> 13:44.660 level description so I can see what I'm doing here. 13:44.660 --> 13:46.490 And we're spawning the actor. 13:46.490 --> 13:52.510 We're spawning it spawn transform setting damage effect params and finishing spawning. 13:52.520 --> 13:56.720 So with that we should see a number of fireballs come out. 13:57.200 --> 13:58.370 Let's give it a shot. 14:00.120 --> 14:03.920 All right, let's see if we get five projectiles. 14:03.930 --> 14:04.650 Boom! 14:04.650 --> 14:05.880 There they are. 14:05.910 --> 14:07.170 Really cool. 14:10.870 --> 14:16.360 Now I notice that the projectiles are spawning right away, and that's because I'm not hooking up my 14:16.360 --> 14:19.520 event received to spawn projectiles. 14:19.540 --> 14:24.430 So with that fixed now we'll get them spawned at the correct time. 14:25.880 --> 14:26.510 Pretty cool. 14:26.510 --> 14:31.280 And actually at this angle I can actually kill three of them. 14:31.280 --> 14:34.340 I can hit all three, which is pretty nice. 14:36.500 --> 14:37.490 Look at that. 14:38.620 --> 14:42.940 Okay, so now we have the ability to spawn five projectiles at once. 14:42.940 --> 14:49.150 And also with that pitch override, this is kind of cool because if I give it a pitch override of 45, 14:49.180 --> 14:54.550 then we'll spawn it 45 upward, 45 degrees upward. 14:55.550 --> 15:02.130 Now, obviously that looks definitely too high, but what if our projectiles had gravity? 15:02.150 --> 15:02.720 Right? 15:02.720 --> 15:03.980 Then it would be different. 15:03.980 --> 15:10.190 So in the next video, we're going to work on giving our projectiles gravity, as well as making them 15:10.190 --> 15:17.420 homing missiles so that our pitch override is going to look a little bit better when we set it to anything 15:17.450 --> 15:18.830 other than zero. 15:18.920 --> 15:21.500 With zero, they just go straight. 15:23.530 --> 15:24.340 Like so. 15:25.400 --> 15:25.910 Okay. 15:25.910 --> 15:26.940 Excellent job. 15:26.960 --> 15:28.670 I'll see you in the next video.