WEBVTT 00:06.940 --> 00:08.170 Welcome back. 00:08.290 --> 00:15.280 Now, here in GE damage we're hard coding a 25 for our scalable float magnitude. 00:15.520 --> 00:23.080 Now sometimes we'd like to be able to set the magnitude when we're creating the effect spec or perhaps 00:23.080 --> 00:26.200 applying the effect we'd like more control. 00:26.410 --> 00:33.430 For instance, from our gameplay ability, our ability may have a base damage value that we'd like to 00:33.430 --> 00:37.660 set on the gameplay effect that our ability is causing. 00:37.960 --> 00:44.410 Let's see how we're handling setting the effect or effect spec when we're launching a projectile. 00:45.290 --> 00:53.270 So if we go into abilities and or a projectile spell, we'll see that we're creating a gameplay effect 00:53.270 --> 01:00.760 spec with make outgoing spec and we're taking the spec handle and we're setting that on the projectile. 01:00.770 --> 01:06.050 The projectile has a damage effect spec handle variable that we're setting. 01:06.350 --> 01:11.540 So we're setting the damage gameplay effect for the projectile spell. 01:11.810 --> 01:17.750 But as soon as we set that spec handle for our projectile which will apply it later, that spec handle 01:17.750 --> 01:24.260 should carry the information for how much damage to cause and we should be able to set that here from 01:24.260 --> 01:28.490 the ability if our ability wants to have some kind of value. 01:28.490 --> 01:33.650 In other words, the ability itself should determine how much damage to do, not the effect. 01:33.650 --> 01:38.780 And to do that we can use the set by caller option on the gameplay effect. 01:38.780 --> 01:45.930 So currently our damage gameplay effect uses scalable float for its magnitude calculation type. 01:46.020 --> 01:52.500 And we know that this is great because we can use curve tables to scale the magnitude, but we have 01:52.500 --> 01:56.790 a fourth option that we haven't learned about yet called set by caller. 01:57.120 --> 02:03.660 And it says this magnitude will be set explicitly by the code slash blueprint that creates the spec. 02:03.660 --> 02:10.680 So that's what we'd like to do Now, set by caller magnitudes are pairs their key value pairs where 02:10.680 --> 02:12.630 the key is a gameplay tag. 02:12.630 --> 02:17.670 So we need a gameplay tag to identify the set by caller magnitude. 02:17.730 --> 02:25.740 So first we're going to make a gameplay tag for damage and we can do that by going into our gameplay 02:25.740 --> 02:27.750 tags Singleton class. 02:27.750 --> 02:30.630 So it's here in Aura gameplay tags. 02:30.630 --> 02:34.410 We're going to make a gameplay tag simply called damage. 02:34.530 --> 02:43.800 So just under our inputs, I'm going to make a new gameplay tag called Damage and we need to make sure 02:43.800 --> 02:47.190 that we're creating this native gameplay tag. 02:47.670 --> 02:54.840 So opening the CPP file here is where we're creating all of our gameplay tags and just under input tags 02:54.840 --> 02:56.550 we're going to make damage. 02:56.850 --> 03:03.690 So let's go ahead and just copy and paste the last input tag that we declared. 03:03.690 --> 03:12.450 And this one will be the damage tag and its name is simply going to be damage and the input string can 03:12.450 --> 03:14.490 simply be damage. 03:14.700 --> 03:21.450 So now we've got a native gameplay tag called Damage and we can use this and we're going to use that 03:21.450 --> 03:29.310 in our projectile spell as I'd like to get those gameplay tags or a gameplay tags, I'm going to include 03:29.310 --> 03:30.690 that header file here. 03:32.720 --> 03:38.480 So it's aura and public and aura gameplay tags. 03:39.230 --> 03:41.400 So we can get those gameplay tags. 03:41.420 --> 03:48.050 And I'm going to do this right here before we set the projectiles damage effect spec handle, we're 03:48.050 --> 03:54.260 going to say F or a gameplay tags gameplay tags equals F. 03:54.980 --> 03:57.170 Or a gameplay tags get. 03:57.590 --> 04:03.500 So now we have those tags and now we can use a set by caller magnitude. 04:03.590 --> 04:07.700 Now this is done using the ability system Blueprint library. 04:07.700 --> 04:12.710 So we're going to say you ability system, blueprint library. 04:13.070 --> 04:19.190 And the function we're interested in is called assign tag set by caller magnitude. 04:19.370 --> 04:26.540 Now assign tags set by caller magnitude is going to require a gameplay effect spec handle. 04:26.540 --> 04:27.500 And we have one. 04:27.500 --> 04:32.360 It's called spec handle, so we're going to pass that in next. 04:32.360 --> 04:36.020 It requires a gameplay tag and it's called data tag. 04:36.020 --> 04:43.670 So this is how we identify that magnitude value because you can assign multiple set by caller magnitudes 04:43.670 --> 04:45.530 to a gameplay effect spec. 04:45.530 --> 04:50.060 We're going to set a key value pair where the key is the damage tag. 04:50.060 --> 04:57.510 So we're going to use gameplay tags, dot damage and the magnitude is whatever we decide here. 04:57.540 --> 05:01.560 Our aura projectile spell could have its own damage variable. 05:01.710 --> 05:05.460 But to see how this works, I'm just going to hardcode a value. 05:05.460 --> 05:11.610 Let's use 50 and that's all we have to do to set the set by caller magnitude. 05:11.610 --> 05:18.030 So now this spec handle is carrying along a pair, a key value pair. 05:18.030 --> 05:23.640 The key is the damage gameplay tag and the value is the magnitude 50. 05:23.670 --> 05:30.360 Now we just need to be able to access that key value pair from within our gameplay effect when applying 05:30.360 --> 05:31.350 a modifier. 05:31.350 --> 05:32.700 So let's do that. 05:32.730 --> 05:33.120 Now. 05:33.120 --> 05:34.350 I still have the editor open. 05:34.350 --> 05:39.930 I'm going to go ahead and close it so that I can do a fresh compile and launch and we'll go back into 05:39.930 --> 05:41.250 our gameplay effect. 05:43.540 --> 05:50.980 So I'm going to go ahead and open damage and scroll down and now we're going to change our magnitude 05:50.980 --> 05:52.350 calculation type. 05:52.360 --> 05:56.740 We're going to change it from scalable float to set by caller. 05:56.890 --> 06:02.980 Now, once we do this, we have a set by caller magnitude dropdown which we can expand. 06:03.070 --> 06:08.860 Now, because we can have multiple set by caller magnitudes on a given gameplay effect spec, we need 06:08.860 --> 06:14.320 to choose which one and they're identified by the key the gameplay tag key. 06:14.350 --> 06:19.090 So for the data tag we have to select the tag that we want. 06:19.120 --> 06:26.290 We're going to select damage and as soon as we select damage now this modifier will do 50 damage. 06:26.290 --> 06:26.560 Why? 06:26.590 --> 06:34.660 Because that's the value we associated with this key when we called assign tag set by caller magnitude. 06:34.660 --> 06:37.470 So we should see 50 damage being done. 06:37.480 --> 06:42.700 Let's go ahead and test this out and see if we do more damage than last time. 06:42.700 --> 06:44.150 And in fact, we do. 06:44.180 --> 06:46.520 It looks like we're doing 50 damage. 06:47.130 --> 06:47.820 Great. 06:48.210 --> 06:53.160 So that's how we can use the set by caller magnitude calculation type. 06:53.280 --> 06:58.230 Now, yes, we're moving one hard coded value into another class. 06:58.230 --> 07:05.910 Right now we're hard coding 50, but at least now our gameplay ability has control over how much damage 07:05.910 --> 07:07.920 is done by our projectile. 07:07.920 --> 07:13.740 It's not just set in the gameplay effect itself, it's now something we control from code and we're 07:13.740 --> 07:16.380 going to control that from the gameplay ability. 07:16.380 --> 07:24.930 And I think gameplay abilities can have a base damage property that we can set based on our gameplay 07:24.930 --> 07:26.220 abilities level. 07:26.340 --> 07:33.570 So we're going to handle adding a member variable to the aura gameplay ability class to handle damage 07:33.570 --> 07:34.950 and we'll do that next. 07:34.980 --> 07:37.200 So great job and I'll see you soon.