WEBVTT 00:07.350 --> 00:08.640 Welcome back. 00:08.670 --> 00:15.930 Now in this video we're going to take a look at the knockback that we cause from our Arcane Shards ability. 00:16.200 --> 00:22.260 Now if I hit the enemy then knockback seems to work but the enemy goes straight up. 00:22.950 --> 00:28.290 It doesn't really matter what direction I attack it from, it just goes straight into the air. 00:28.560 --> 00:30.660 Now, it shouldn't really go straight into the air. 00:30.660 --> 00:34.440 It should be flying away from my character. 00:34.440 --> 00:41.760 If my character is over here to the right and I impart the knockback, then it should be knocking my 00:41.760 --> 00:44.370 enemy away from my character. 00:44.400 --> 00:47.070 Now, the reason it's not is actually a bug. 00:47.070 --> 00:51.510 In my case, you might be seeing the correct behavior, but I'm not. 00:51.510 --> 00:57.120 And the reason I know this is a bug specifically with this character is because I can drag in my other 00:57.120 --> 00:57.720 characters. 00:57.720 --> 00:59.340 I can bring in a demon. 00:59.340 --> 01:02.670 For example, I can bring in a ghoul. 01:04.480 --> 01:07.150 And let's get in a shaman. 01:09.180 --> 01:14.220 And if I come back in here and I use arcane shards. 01:15.050 --> 01:17.270 Then they're all knocking away from me. 01:17.270 --> 01:19.460 All except that pesky little goblin. 01:19.460 --> 01:21.170 It's just going straight up. 01:21.170 --> 01:23.750 But the others, they go away from me. 01:24.660 --> 01:28.260 So knockback is at least doing its job in that case. 01:28.260 --> 01:33.390 But my goblin is bugged, so I'm going to have to create a new goblin spear. 01:33.630 --> 01:34.380 I can do that. 01:34.380 --> 01:42.450 I can right click on BP enemy base, create a Child Blueprint class and call this BP underscore Goblin. 01:43.920 --> 01:45.060 Spear. 01:46.050 --> 01:49.020 And I just need to set all of its properties. 01:49.110 --> 01:53.670 So I'm going to time lapse while I just set all the properties for my goblin spear. 02:25.840 --> 02:32.890 Okay, so now that I have a new Goblin Spear class, I can take my goblin spear that's defected and 02:32.890 --> 02:38.920 delete it from the world first, and then go into Goblin Spear and delete the blueprint. 02:38.920 --> 02:40.750 I'm going to force delete it. 02:41.450 --> 02:47.930 And take my new goblin spear and move it into my Goblin spear folder and bring in one of these goblin 02:47.930 --> 02:51.140 spears, and let's just see if that works as it should. 02:52.040 --> 02:53.000 And it does. 02:55.030 --> 02:57.160 Okay, so that's great. 02:57.160 --> 03:02.800 But the thing is, what if I don't want my enemies to fly away from me? 03:02.830 --> 03:06.850 What if I want them to fly away from the arcane shards themselves? 03:06.850 --> 03:09.520 So if I spawn the shards on this side. 03:10.610 --> 03:12.710 I want them to fly towards me. 03:12.710 --> 03:18.770 In other words, I want the knockback direction to be calculated based on the location of the shard. 03:19.190 --> 03:20.540 Well, I can do that. 03:20.540 --> 03:27.140 Let's take a look at our shards ability, ability system, aura abilities, arcane arcane shards. 03:27.140 --> 03:32.840 And we can open this ability and we can see where we're applying radial damage to player. 03:32.840 --> 03:40.430 We're making effect params from class defaults and make damage effect params from class defaults. 03:42.990 --> 03:50.160 If we take a look at that function in our Aura Damage gameplay ability class, we'll see how it's calculating 03:50.160 --> 03:58.440 that knockback, it's setting knockback force based on a calculation from the avatar actor to the target 03:58.440 --> 03:59.160 actor. 03:59.160 --> 04:03.300 So that's why we're always knocking those enemies away from aura. 04:03.660 --> 04:07.440 And of course, there's a rotation pitch that's an override. 04:07.980 --> 04:13.080 Now we can pass in a vector if we like to set the knockback force. 04:13.080 --> 04:20.820 So that way we would then be forced to pass one in in case we don't want this behavior for all knockback 04:20.820 --> 04:21.330 forces. 04:21.330 --> 04:21.930 Right. 04:21.930 --> 04:25.050 We can do the same thing for death impulse as well. 04:25.050 --> 04:27.570 So we can have a number of inputs for this. 04:27.570 --> 04:34.410 We can have a knockback force direction that we pass in a death impulse direction, a pitch override 04:34.410 --> 04:41.490 for these, and then perhaps a boolean for whether or not we should override our knockback force and 04:41.490 --> 04:46.140 death impulse, or should we just calculate them based on the target actor. 04:46.140 --> 04:49.620 So I'm going to add some more input parameters to this function. 04:50.140 --> 04:55.060 So I'm going to put all of the inputs on their own lines, because there are going to be a lot of them 04:55.060 --> 04:55.720 now. 04:56.050 --> 05:03.700 And in addition to target actor and a radial damage origin, I'm going to pass in some knockback parameters. 05:03.730 --> 05:10.240 Now I'm going to have booleans that I want to pass in to check to see if we should even override these. 05:10.240 --> 05:10.690 Right. 05:10.690 --> 05:20.590 So what I'm going to do is say bool be override knockback direction, and I'll give these default values 05:20.590 --> 05:23.080 so we don't have to pass them in if we don't want to. 05:23.080 --> 05:25.090 So it'll be false by default. 05:25.740 --> 05:32.580 And then we'll have an f vector called in knockback direction. 05:33.060 --> 05:34.110 Override. 05:34.110 --> 05:38.760 We'll just call it knockback direction override and I'll set it equal to f vector. 05:38.910 --> 05:41.250 Zero vector by default. 05:41.820 --> 05:45.060 And I'll have a bool called be override. 05:45.120 --> 05:46.620 Death impulse. 05:47.750 --> 05:51.950 Set to false by default and have an f vector. 05:52.460 --> 05:59.450 Def impulse direction override also set to an empty f vector. 05:59.540 --> 06:00.980 The zero vector. 06:01.740 --> 06:07.080 And then we can have a pitch override, and we can have a bool for whether or not to override it. 06:07.110 --> 06:09.630 We can say B override pitch. 06:11.130 --> 06:18.000 Equals false by default and a float pitch override, which is zero by default. 06:18.180 --> 06:21.570 So now we have a whole bunch of parameters we can add. 06:21.570 --> 06:22.770 So I'm going to go ahead. 06:22.770 --> 06:27.300 And the quickest way I can do this is by clicking Generate definition. 06:27.300 --> 06:30.600 Because now I have the correct signature. 06:30.600 --> 06:38.460 And I can just copy the contents of my old function and paste it in the new one and delete the old one. 06:39.420 --> 06:43.920 That's the quickest, laziest way to fix that signature. 06:44.280 --> 06:46.950 Okay, so now we need to check a couple of booleans. 06:46.950 --> 06:47.280 Right. 06:47.280 --> 06:53.460 We should check whether or not we want to override our knockback direction and our death impulse. 06:53.460 --> 06:55.860 So here's what we'll do. 06:56.070 --> 07:03.570 We'll say if B override knockback direction then we'll override knockback direction. 07:03.570 --> 07:04.290 Right. 07:04.530 --> 07:12.360 And when we override knockback direction we're going to use the knockback direction override vector 07:12.360 --> 07:13.110 only. 07:13.110 --> 07:19.590 We're going to take that vector and override its pitch if we should override the pitch. 07:19.590 --> 07:24.600 So if B override pitch then we'll override the pitch. 07:24.600 --> 07:31.920 I'm going to do so by creating an F rotator called knockback rotation. 07:32.520 --> 07:39.300 And that's going to be our knockback direction that we're passing in that are we're going to be override 07:39.420 --> 07:42.120 with and call rotation on that. 07:42.120 --> 07:43.740 So it's now a rotator. 07:43.740 --> 07:52.860 And I'm going to take knockback rotation dot pitch and set it equal to the override pitch override. 07:54.590 --> 07:58.160 And then I'm going to set my knockback force. 07:58.160 --> 08:05.990 So I'm going to take params dot knockback force and set it equal to my new knockback direction which 08:05.990 --> 08:10.580 is going to be knockback rotation dot vector. 08:11.510 --> 08:15.020 And I'm going to scale it by knockback force magnitude. 08:16.210 --> 08:20.770 And now we've overridden our pitch for knockback force. 08:20.800 --> 08:27.670 Now, if we're not overriding the pitch, then all we need to do is set our knockback force equal to 08:27.670 --> 08:28.870 the knockback direction. 08:28.870 --> 08:33.190 Override times our knockback force magnitude. 08:33.190 --> 08:35.950 So we'll do that first before overriding it. 08:35.950 --> 08:44.800 We're going to say params dot knockback force equals knockback, direction, override times, knockback 08:44.800 --> 08:46.270 force magnitude. 08:46.270 --> 08:52.150 And of course we could take that knockback direction override and just make sure that it's normalized. 08:53.380 --> 08:58.120 So we do that first we set it, and then if we override the pitch, we set it again. 08:58.510 --> 09:07.030 And I'm noticing that knockback direction override is missing an R not the biggest deal but I'm going 09:07.030 --> 09:08.080 to just fix it. 09:08.560 --> 09:12.460 Knockback direction override with two R's. 09:15.150 --> 09:16.890 And we'll fix it down here. 09:22.940 --> 09:28.430 Okay, so we override knockback direction with the vector passed in. 09:28.430 --> 09:34.100 If that boolean is true, and we override its pitch with the pitch override. 09:34.100 --> 09:39.260 If that boolean is true, we're going to do the same thing now for our death impulse. 09:39.260 --> 09:48.500 So we're going to say if B override death impulse we're going to take our death impulse direction override. 09:48.500 --> 09:50.810 Make sure it's normalized first. 09:51.830 --> 09:53.180 And then set params. 09:53.360 --> 09:55.790 Death impulse equal to death. 09:55.790 --> 09:56.210 Impulse. 09:56.210 --> 09:56.720 Direction. 09:56.720 --> 09:58.130 Override times. 09:58.130 --> 09:59.870 Death impulse magnitude. 10:00.770 --> 10:02.990 And then we'll check if we should override the pitch. 10:02.990 --> 10:05.510 So if we override pitch. 10:06.680 --> 10:08.480 We'll make an EF rotator. 10:08.630 --> 10:11.240 Death impulse rotation. 10:11.660 --> 10:13.910 Equal to death. 10:13.910 --> 10:18.200 Impulse direction override dot rotation. 10:20.360 --> 10:26.990 And we'll take death impulse rotation, dot pitch and set it equal to pitch override. 10:27.290 --> 10:35.120 And then we'll set params dot death impulse equal to death impulse rotation dot vector. 10:36.110 --> 10:39.020 Times death impulse magnitude. 10:40.040 --> 10:42.980 So now we've got these overrides that we're doing. 10:42.980 --> 10:50.510 And if these override booleans are false then we can set our death impulse based on this calculation 10:50.510 --> 10:51.290 here. 10:51.290 --> 10:55.310 And now that pitch override we're passing in is going to matter. 10:55.310 --> 10:59.030 So I'm going to take this f rotator rotation. 10:59.330 --> 11:02.330 And we'll just calculate it first up here. 11:02.330 --> 11:06.680 So we don't have to calculate it twice if we need it at all. 11:07.070 --> 11:10.850 And then we'll have an else case for both of these if statements. 11:12.410 --> 11:15.710 We'll go ahead and calculate this two target. 11:16.470 --> 11:17.880 Up here as well. 11:18.270 --> 11:22.110 And we'll just check if be override pitch as well. 11:22.110 --> 11:25.560 And if so we'll go ahead and override the rotation pitch. 11:25.920 --> 11:28.530 We'll do that before we turn it into a vector. 11:28.530 --> 11:29.640 So we'll do it right here. 11:29.640 --> 11:35.160 If override pitch rotation dot pitch equals pitch override. 11:35.160 --> 11:41.880 So we can still override the pitch even if we don't override the knockback and death impulse directions. 11:41.880 --> 11:47.640 Once we have this two target, then we'll use it in the else cases here. 11:47.910 --> 11:57.060 So we'll say params dot knockback force equals two target times knockback force magnitude. 11:57.270 --> 12:01.350 And we'll set death impulse down here params. 12:03.100 --> 12:09.040 Dot death impulse equals two target times death impulse magnitude. 12:10.480 --> 12:13.330 And now we don't need this here. 12:13.360 --> 12:20.410 Of course, we should actually check if the target actor is valid before doing any of this here. 12:21.150 --> 12:22.500 So we'll just check it here. 12:22.500 --> 12:29.700 We'll say if is valid target actor and then we'll place these here. 12:29.910 --> 12:32.970 Of course these are now in the scope of this if statement. 12:32.970 --> 12:36.510 So we might as well just check here. 12:36.510 --> 12:47.670 If be override death impulse and if be override knockback direction. 12:48.410 --> 12:49.820 And we'll just set these here. 12:49.820 --> 12:58.010 We'll just set params dot knockback force right there and params dot death impulse right there. 12:59.070 --> 13:03.480 And we could do knockback first if we want this to be consistent. 13:03.480 --> 13:04.680 So like this. 13:04.830 --> 13:09.120 And then we don't need the else cases down here I think this will be a little bit cleaner. 13:10.620 --> 13:18.570 And if we look closely up here when our target actor is valid, we actually only want to set these vectors 13:18.570 --> 13:21.330 if the corresponding override booleans are false. 13:21.330 --> 13:23.850 So these actually need not here. 13:23.880 --> 13:30.180 And finally, after all this we can remove this calculation which was setting our. 13:30.930 --> 13:32.760 Knockback force and death impulse. 13:32.760 --> 13:34.560 We no longer need to do it there. 13:35.140 --> 13:38.200 And with that, we can compile and test this out. 13:39.760 --> 13:41.740 Okay, so we're back in the editor. 13:41.740 --> 13:48.700 I'm going to go into ability system aura abilities, arcane Arcane shards and open Arcane shards and 13:48.700 --> 13:50.980 back in radial damage to player. 13:50.980 --> 13:57.310 We can now start overriding some of these values and make damage effect params from class defaults. 13:57.310 --> 14:04.690 And first I need to get that knockback direction, which I want to be the direction from my shard spawn 14:04.690 --> 14:07.390 location to the target actor. 14:07.870 --> 14:11.890 And to get that vector we can get the actor location. 14:14.310 --> 14:17.820 And we can subtract shard spawn location from it. 14:19.620 --> 14:26.550 This gives me the vector from the shard spawn location to the actor, and I can plug that into the knockback 14:26.550 --> 14:32.580 direction override and the death impulse override, and I can check the checkboxes to override both 14:32.580 --> 14:33.300 of those. 14:33.300 --> 14:37.710 And I can also override the pitch with say, 45 degrees. 14:37.710 --> 14:40.200 Maybe 35 degrees should be fine. 14:40.200 --> 14:42.720 And with that we can test this out. 14:43.200 --> 14:50.670 So I'm going to try to launch these characters towards Aurra by spawning the shards on the other side. 14:52.060 --> 14:53.350 And there we go. 14:57.900 --> 15:00.030 So where are those shards? 15:00.030 --> 15:04.620 Spawn determines which direction those enemies will be knocked in. 15:10.990 --> 15:11.950 Awesome. 15:13.120 --> 15:16.840 Okay, so our knockback force is working pretty well. 15:16.840 --> 15:21.400 And with that, we're just about done with our Arcane Shards ability. 15:21.400 --> 15:29.710 We just need to make sure that the number of shards spawned is set based on our ability level, and 15:29.710 --> 15:32.200 we can also use a description. 15:32.200 --> 15:36.610 In fact, we could use a description for our electrocute ability as well. 15:36.610 --> 15:42.460 So far, it's just our Firebolt that has a description so we can take care of those next. 15:42.790 --> 15:47.830 And with that we now have three offensive abilities that work. 15:48.160 --> 15:49.240 Awesome job. 15:49.240 --> 15:50.350 I'll see you soon.