WEBVTT 00:06.870 --> 00:08.040 Welcome back. 00:08.370 --> 00:15.300 Now, so far, all of our gameplay effects are using scalable float for their modifier magnitudes. 00:15.450 --> 00:25.230 For example, if I open actor and potion and potion heal and I scroll down, I can see that right here 00:25.230 --> 00:27.130 I have a single modifier. 00:27.150 --> 00:34.290 It's modifying the health attribute, it's adding to it, and the modifier magnitude calculation type 00:34.290 --> 00:36.000 is set to scalable float. 00:36.210 --> 00:44.910 Now the dropdown shows us three other options and attribute based is the next one After scalable float 00:44.910 --> 00:52.230 and attribute based is quite an interesting and useful option for magnitude calculation type. 00:52.230 --> 01:01.230 It's actually very cool and it gives us the ability to have an attribute change based on other attribute 01:01.230 --> 01:02.100 values. 01:02.430 --> 01:08.770 This can make it really easy to have an attribute that is derived from other attributes. 01:09.220 --> 01:16.090 So in order to see how attribute based gameplay effects work, I'd like to make a new effect. 01:16.090 --> 01:25.480 Actor That applies a test effect that uses attribute based modifier magnitude calculation types. 01:25.480 --> 01:28.120 So let's go ahead and create one of those. 01:28.120 --> 01:34.660 So first here in Actor, I'm going to make a new folder called Test Actor. 01:36.140 --> 01:39.530 And here in test actor I'm going to make an effect. 01:39.530 --> 01:41.520 Actor And a gameplay effect. 01:41.540 --> 01:44.090 So I'll start with the effect. 01:44.090 --> 01:47.870 Actor Searching for aura effect Actor. 01:48.610 --> 01:52.090 And I'll call this BP underscore test actor. 01:53.290 --> 01:56.860 I'm going to open it up and I'm going to give it a. 01:58.050 --> 01:59.280 Box collision. 01:59.850 --> 02:06.540 And here in the event graph with the box selected, I'm going to use on component began overlap. 02:08.290 --> 02:13.240 And we'll call apply effect to Target. 02:14.070 --> 02:16.230 So we'll go ahead and hook these up. 02:17.340 --> 02:25.530 And I'd like to make a gameplay effect to apply and we can just make it an instant gameplay effect. 02:25.650 --> 02:31.500 So I'm going to get the instant gameplay effect class and we can make a gameplay effect and apply that. 02:31.530 --> 02:36.440 Now for testing purposes, I'm going to make the box a little bit more visible. 02:36.450 --> 02:42.930 I'm going to select my box and set my line thickness to something a little bigger. 02:43.670 --> 02:50.180 Perhaps five, and I'm going to search for the rendering section and uncheck Hidden in game. 02:50.930 --> 02:57.140 Compile save and now I have my test actor and I can just drag one in right here. 02:59.370 --> 03:02.920 Now we just need an effect to apply. 03:02.940 --> 03:07.470 So let's make that I'm going to create a new blueprint class. 03:07.830 --> 03:09.210 Gameplay Effect. 03:11.670 --> 03:15.420 And I'll call this GE underscore test. 03:15.570 --> 03:17.490 Attribute based. 03:18.740 --> 03:22.580 And open that up and we'll go ahead and configure this. 03:22.580 --> 03:29.120 But first I'm going to go to my test actor and set its instant gameplay effect. 03:29.780 --> 03:33.290 So all the way up at the top we have instant gameplay effect class. 03:33.290 --> 03:36.620 It's going to be GE test attribute based. 03:36.650 --> 03:42.860 We don't care about the instant effect application policy because we're just calling apply effect to 03:42.860 --> 03:44.120 target directly. 03:44.150 --> 03:44.720 Okay. 03:44.720 --> 03:49.160 So now we can configure this gameplay effect. 03:49.160 --> 03:51.620 It's going to be an instant gameplay effect. 03:51.650 --> 03:56.000 So all we need to care about here is adding a modifier. 03:56.000 --> 04:00.050 And if I click plus to add a new modifier, I can expand it. 04:00.050 --> 04:01.790 I can choose an attribute. 04:01.790 --> 04:04.370 I think I'll go ahead and choose the health attribute. 04:04.370 --> 04:07.940 And for modifier OP, we can leave it at Add. 04:07.940 --> 04:14.690 And for modifier magnitude, I'm going to expand it and for the magnitude calculation type instead of 04:14.690 --> 04:18.620 scalable float, I'm going to choose attribute based. 04:18.710 --> 04:25.190 Now, as soon as I do that, suddenly we have this attribute based magnitude which we can expand and 04:25.190 --> 04:29.610 we have quite a few options here and we're going to discuss all of these. 04:29.610 --> 04:32.130 But for now, just ignore the first three. 04:32.160 --> 04:38.790 We'll talk about these shortly, but take a look at backing attribute, expand that and we have the 04:38.790 --> 04:45.060 option to choose an attribute to capture and we can choose the attribute source. 04:45.090 --> 04:53.580 You see, this gameplay effect is going to be caused by something to something so we can capture the 04:53.580 --> 04:56.250 attribute from the source or the target. 04:56.700 --> 05:03.150 Now I'm going to choose Target because we're applying this gameplay effect to Aura when she overlaps 05:03.150 --> 05:03.840 with it. 05:03.840 --> 05:06.450 So I'm going to capture attributes from Aura. 05:06.630 --> 05:10.590 Now we'll talk more about Snapshot later in the course. 05:10.590 --> 05:18.210 It has to do with when to capture the attribute, when should we use that attributes value? 05:18.240 --> 05:24.690 Should we use it when the gameplay effect spec that caused this gameplay effect was created or when 05:24.690 --> 05:25.830 it was applied? 05:25.830 --> 05:30.990 Snapshot determines when exactly we'll be capturing that attribute. 05:31.020 --> 05:37.050 We're going to leave it unchecked for now, but we're not really going to discuss it until we have a 05:37.050 --> 05:40.890 situation more appropriate to consider it. 05:41.160 --> 05:47.250 Now, for the backing attribute, we can choose an attribute, and since I chose Target for the attribute 05:47.250 --> 05:54.720 source, then we know that we'll be taking that attribute from Aura as soon as she overlaps with our 05:54.720 --> 05:57.180 box component on Test Actor. 05:57.600 --> 06:05.460 And if I choose one of my attributes, for example, the vigor attribute, then by default, all we're 06:05.460 --> 06:13.440 going to do is add Since our modifier op is Add, we're going to add the value of vigor to our health. 06:13.440 --> 06:15.240 So let's see this in action. 06:15.240 --> 06:17.000 I'm going to go back and press play. 06:17.010 --> 06:23.880 I'm going to show debug ability system and I see that my health is 50 and my vigor is nine. 06:23.880 --> 06:29.700 So as soon as I overlap with this volume, now I see that my health is 59. 06:29.700 --> 06:30.270 Why? 06:30.300 --> 06:32.490 Because we had vigor added to it. 06:32.520 --> 06:35.880 We had the value of vigor added to it. 06:35.940 --> 06:38.490 So that seems simple enough, right? 06:38.490 --> 06:44.970 But the thing is, with all these options, this can get complicated very quickly and we know that we 06:44.970 --> 06:47.430 can add multiple modifiers. 06:47.430 --> 06:55.950 For example, what if I collapse this index for my modifiers and I click plus on the modifiers bar one 06:55.950 --> 06:56.490 more time? 06:56.490 --> 07:03.960 Now we have two elements in this array, and if I expand this one, I can choose to have another modifier. 07:03.960 --> 07:06.060 Now let's say I choose health again. 07:06.060 --> 07:11.400 So I have two modifiers modifying my health and I can leave this as Add. 07:11.400 --> 07:18.810 And let's say that I expand modifier magnitude, I change the calculation type to attribute based. 07:18.810 --> 07:26.010 I expand attribute based magnitude and expand backing attribute, and this time choose a different attribute 07:26.010 --> 07:27.300 like strength. 07:27.300 --> 07:30.240 And I choose the attribute source to be target. 07:30.240 --> 07:32.550 So now I'm going to collapse this. 07:32.550 --> 07:36.090 My modifiers array has two elements in it. 07:36.120 --> 07:43.410 They're both set to add for their modifier OP, but the first one is backed by the attribute vigor. 07:43.440 --> 07:46.470 The second is backed by the attribute strength. 07:46.470 --> 07:53.070 Now you would just expect to have vigor and strength added to our health. 07:53.070 --> 07:55.560 Well, let's see if that's the case. 07:57.000 --> 08:01.680 I see that my health is 50, vigor is nine and strength is ten. 08:01.680 --> 08:05.270 So if I overlap now, my health is 69. 08:05.280 --> 08:06.510 It was 50. 08:06.540 --> 08:09.420 We added nine and we added ten. 08:09.450 --> 08:10.860 That equals 69. 08:10.860 --> 08:13.500 So it works as expected. 08:13.680 --> 08:19.620 Now, when all of our modifier operations are just Add, then it's pretty intuitive. 08:19.620 --> 08:21.480 We just add them all together. 08:21.480 --> 08:28.650 But it's important to understand exactly how these modifiers work and how the order is taken into account. 08:28.650 --> 08:37.350 So we're going to have a more in depth conversation about how these modifiers are applied and how it 08:37.350 --> 08:40.500 works depending on what the modifier operation is. 08:40.500 --> 08:47.550 And after we do that, we're going to then start talking about these additional parameters coefficient 08:47.550 --> 08:54.060 pre-multiply, additive, post-multiply additive and so on, so that we understand completely how all 08:54.060 --> 08:55.170 of these things work. 08:55.170 --> 09:02.920 So in the next video we're going to take a deep dive looking at the modifiers and the order of operations, 09:02.920 --> 09:06.490 depending on what our modifier ops are set to. 09:06.490 --> 09:09.190 So we'll do that next and I'll see you soon.