WEBVTT 00:00.720 --> 00:06.680 So, listen, we're going to shatter this object and then use the solar system to drop it onto the floor. 00:07.230 --> 00:13.110 So just for fun, I'm going to make a floor here and I'm going to save this out actually before I get 00:13.110 --> 00:13.530 started. 00:14.130 --> 00:17.610 And let's grab this little cylinder and raise it up. 00:17.610 --> 00:23.910 So we're going to shatter it onto the floor and rotate it at some angle of some kind. 00:24.900 --> 00:29.160 And so we want to delete the history on this thing. 00:29.160 --> 00:32.420 The bullet solver needs no history on an object. 00:32.430 --> 00:36.600 So even though this is a pretty new object, I just extrude a couple of things. 00:36.600 --> 00:38.310 You have to have no history on something. 00:38.640 --> 00:41.680 I'm sorry, not for the bullet solver, but for the shattered. 00:41.700 --> 00:45.620 Rather, it will not let you shatter an object if there's any history. 00:45.630 --> 00:47.280 So you have to go delete by type history. 00:47.380 --> 00:53.400 OK, and when you get to the shatter from the effects tab here, let's go to effects and we go to shatter. 00:53.790 --> 00:54.930 And there's three different types. 00:54.930 --> 00:58.170 And we want to do a solid shatter because we want solid pieces. 00:58.170 --> 00:58.920 And 01:01.560 --> 01:04.330 so yeah, let's just use it and you can see how that works. 01:04.330 --> 01:05.100 So I'll head apply. 01:06.360 --> 01:11.010 And it shatters the object, so in the outliner, we get it, keeps it. 01:11.040 --> 01:12.330 We have an original object here. 01:12.630 --> 01:13.500 We can hide that. 01:13.500 --> 01:19.070 And now we have a group of each of the shards of the object. 01:19.260 --> 01:24.750 And you can notice that, you know, if we were to drop this thing on the ground, each one of these 01:24.750 --> 01:34.260 shards is kind of evenly it's the same size and we can drop it on the ground and use the solver. 01:35.880 --> 01:37.280 So let's just do that first. 01:37.300 --> 01:39.960 Then I'll show you how to shatter this in a better way later. 01:40.440 --> 01:46.020 So we could also let me let me just delete this and also show you the other settings here. 01:46.420 --> 01:47.910 We can hide this. 01:47.920 --> 01:50.220 You have to have it unhidden to actually use this tool. 01:50.710 --> 01:54.050 We can increase the edge jaggedness and apply. 01:55.020 --> 02:03.270 And so each of the shards, if I get an object mode now, the edge and the interior also has a lot more 02:03.480 --> 02:04.260 texture to it. 02:04.260 --> 02:13.820 It's it's jagged, obviously, as the edge jaggedness thing attribute signifies here behind the original. 02:14.340 --> 02:18.660 And so now we have our edge jagged cylinder. 02:19.080 --> 02:20.900 We need to create another rigid set. 02:21.660 --> 02:27.900 So I'll go back to the system as we've done before and we'll say rigid set and we'll go into the attributes 02:27.900 --> 02:29.070 of the bullet solver. 02:29.860 --> 02:40.920 And so if we hit play right now, this should explode because the kind of default settings for the BOLSOVER 02:40.920 --> 02:48.420 is to have a collision shaped margin of zero point zero four, meaning zero point zero four is the margin 02:48.420 --> 02:50.190 to start calculating in collision. 02:50.610 --> 02:57.990 And because we shattered this, these seams of each shard are right on top of each other. 02:58.410 --> 03:05.420 So we need to tell that margin to be at zero because these pieces have no gap between them. 03:05.940 --> 03:10.350 So it'll still probably explode a little bit and that's OK. 03:10.380 --> 03:12.270 But that's one of the first things we need to do. 03:12.300 --> 03:18.800 The other thing we need to do is instead of using a black box collision type, we use a hole. 03:18.840 --> 03:21.520 And I want to show you this in the visualization. 03:21.540 --> 03:22.620 And you can visualize this. 03:22.620 --> 03:23.340 You can try. 03:23.640 --> 03:25.740 Maya crashes on me every time I try to do this. 03:25.740 --> 03:28.590 But if you click this, you will see colors and shape. 03:28.590 --> 03:32.520 And basically what it's doing is is around each shard. 03:32.950 --> 03:34.190 I'm just inside one. 03:34.590 --> 03:38.370 So imagine this shard with a box around it like a bounding box. 03:38.400 --> 03:44.430 So it finds the, you know, maximum distance around the object and create a box. 03:44.910 --> 03:48.010 And that box is where it's using to calculate a collision. 03:48.330 --> 03:54.480 So even though let's say like, you know, there's no object over here because this point of this side 03:54.480 --> 03:55.970 over here, we have four. 03:56.010 --> 04:00.240 We can see it because this point you can draw a straight line across and down here. 04:00.250 --> 04:05.280 So anything that enters in this area, even though it's not a piece of geometry, because we're using 04:05.500 --> 04:12.510 the box, a hole outside the box collision shape, it will think it's colliding with something even 04:12.510 --> 04:13.020 though it isn't. 04:13.200 --> 04:20.130 And so we change the collision shape of this and the bullet solver for the initial state and we can 04:20.130 --> 04:21.690 go to collision shape type. 04:21.750 --> 04:26.730 We need to choose hole and will basically wrap around each of the shards. 04:26.730 --> 04:34.200 So it will be much better representation of collisions for each shape. 04:34.500 --> 04:35.910 So now we hit play. 04:35.910 --> 04:37.200 It's probably going to the same thing. 04:37.500 --> 04:38.910 Oh, I unhide that. 04:38.910 --> 04:40.050 That's why that piece is still there. 04:41.230 --> 04:49.170 So it's not exploding as much as you can tell, but there's more we can do to solve for this and we 04:49.170 --> 04:50.760 need to turn on the ground first off. 04:51.120 --> 04:57.960 So let's go back to the main bullet solver shape here and turn on use ground plain and see it is hitting 04:57.960 --> 04:59.400 the ground kind of accurately. 04:59.850 --> 05:07.410 And if we're using the box shape, you know, it wouldn't wouldn't be as accurate as this even at this 05:07.410 --> 05:07.650 point. 05:07.650 --> 05:15.510 You can see how it's actually touching exactly the point at which it's you know, the shape is is that 05:15.510 --> 05:20.370 but if this is the box, you know, it would be much less accurate, right? 05:20.720 --> 05:21.720 Oh, that's making sense. 05:21.720 --> 05:23.250 And I wish I could visualize it in my head. 05:23.250 --> 05:24.300 Wouldn't crash and I would do it. 05:24.300 --> 05:28.520 But just imagine like a box around this and that's a big no, no, we don't want that. 05:28.530 --> 05:32.310 So that's why we chose the whole collision shape type. 05:33.060 --> 05:38.520 So let's glue shapes and crank this up and that should hold this thing together now. 05:38.850 --> 05:39.720 So let's hit play. 05:39.720 --> 05:46.680 And now because we glued the shapes together at a pretty big threshold and we're seeing max constraints 05:46.680 --> 05:47.190 per body. 05:47.190 --> 05:52.440 So that's saying how many other objects am I going to constrain myself to? 05:52.830 --> 05:55.410 And so six is quite a bit like that. 05:55.410 --> 06:00.180 Wouldn't make sense for like a shard over here to be connected to a shard over here so we can actually 06:00.180 --> 06:05.790 just reduce this down to maybe like two and let's just crank the threshold down and just pull this back. 06:06.360 --> 06:11.490 And we can start increasing or decreasing this threshold. 06:13.490 --> 06:15.470 And see if we can get this thing to break. 06:17.520 --> 06:18.550 How we want it to. 06:19.440 --> 06:20.970 So, yeah, now it's starting to break. 06:22.290 --> 06:27.600 As you'd expect it, and there was a shard of these shards are sticking together because there's this 06:27.600 --> 06:30.770 threshold is not being met for these other shapes. 06:30.780 --> 06:38.910 And so this also gives me a good time to talk about, unfortunately, that bullet is not super accurate 06:38.910 --> 06:39.630 every time. 06:39.660 --> 06:40.030 Right. 06:40.260 --> 06:41.280 You can tell those things. 06:41.280 --> 06:42.210 Just keep playing back. 06:42.220 --> 06:43.590 Haven't changed any settings. 06:44.040 --> 06:46.560 And we're getting a different simulation every time. 06:46.560 --> 06:49.730 Pretty much these have been pretty consistent. 06:49.740 --> 06:53.420 But you can tell at once like this is totally different from what was played. 06:53.580 --> 06:55.200 So we'll get some of these again. 06:55.620 --> 06:58.090 And then for whatever reason, now we get a different one. 06:58.410 --> 07:03.240 So you want to cash these out once you get done. 07:03.240 --> 07:05.430 And I'm going to show you how to do an Olympic cache later. 07:05.820 --> 07:10.770 The only other thing I would say before you'd want to cash this out and the reason why I'm saying you 07:10.770 --> 07:13.710 want to cash it, because like I just said, every SIM is different. 07:13.710 --> 07:15.200 Every time I play this back, it's different. 07:15.660 --> 07:19.950 So if I get one, I'm like, oh, I like this, but I don't cash it, then I'm just kind of screwed. 07:19.950 --> 07:20.250 Right? 07:20.670 --> 07:25.230 So I want to cash it and then I get to decide if I want to keep that cash or not. 07:25.500 --> 07:32.580 But if I play this and I'm like I like, well this you know how this play out and I go to cash it, 07:32.580 --> 07:35.760 I just have to cross my fingers that it does something similar to what I just played back. 07:36.270 --> 07:38.670 So that's kind of a limitation of bullet. 07:39.810 --> 07:45.960 And those dynamics, unfortunately, in my they they can be inconsistent between playbacks. 07:46.410 --> 07:50.400 So that's something you have to anticipate and start to cash things so that you can, like, save it 07:50.730 --> 07:52.440 and then decide whether you like that or not. 07:52.980 --> 07:57.600 The other thing I'm going to say about shattering is that if you can tell there's actually these interior 07:57.600 --> 08:00.240 pieces here and there denoted by yellow. 08:01.470 --> 08:06.530 So what I like to do before I cache something out is let's go to the editor here. 08:06.570 --> 08:07.770 I can click this icon. 08:07.770 --> 08:10.050 I can go to modeling the editor. 08:11.700 --> 08:13.140 You know, it's all the same thing. 08:14.730 --> 08:15.930 What I would do. 08:18.540 --> 08:22.650 And we're not actually getting these pieces here we go. 08:23.790 --> 08:29.520 What I would do, see how we've already it's all on top of each other. 08:29.790 --> 08:36.690 If I got a TV show, I should be able to get these big shards and what I want are these into your pieces. 08:37.530 --> 08:47.270 And it's a little tough because it just kind of automatically makes cuts where it thinks it should cut. 08:47.520 --> 08:48.030 So. 08:49.570 --> 08:56.890 You can go through here and select kind of the shell of his interior pieces, and I just like to before 08:56.890 --> 09:03.940 I get too far with caching all this stuff out is too. 09:06.450 --> 09:13.110 Remove all of the interior pieces over to like one side of your you're zero to one UV space, you can 09:13.110 --> 09:18.590 see one is right here and this up zero is down here and one over here. 09:18.600 --> 09:24.390 So I keep everything zero one and, you know, go through and select. 09:24.540 --> 09:27.690 You know, you make sure you have you, Michelle, because we want to select faces, even though it 09:27.690 --> 09:32.250 kind of it cut it in a way that it almost looks like we're selecting faces because it cut so many different 09:32.250 --> 09:32.700 times. 09:34.290 --> 09:37.590 But I'm actually just selecting the shell of the interior faces. 09:37.590 --> 09:46.620 So this way, when you go to texture the inside to look different than the outside, all of your movies 09:46.620 --> 09:48.150 will already be where they need to be. 09:49.350 --> 09:54.540 So you can do whatever else you want to with them so you can like you know, it's easier to select them 09:54.540 --> 10:00.240 with, you know, whichever way you want to select them and later on figure out how to texture it. 10:00.240 --> 10:01.770 That's that's a way to do that. 10:02.100 --> 10:04.080 So that's how you shatter an object. 10:04.440 --> 10:11.040 In the next lesson, we're going to look closer into using both Silver and our main animations scene. 10:11.340 --> 10:15.180 So we're going to take a step back and talk a little bit more about a little caches and why they're 10:15.180 --> 10:19.800 important to simulations and open up the animation scene we're going to be working with. 10:19.800 --> 10:20.610 So thanks for watching.