WEBVTT 1 00:00:00.010 --> 00:00:04.320 So before we dive into explaining the data structure and more abstract concepts that 2 00:00:04.320 --> 00:00:09.920 geometry nodes depend on, I want to start out by showing you the very basics that you need to know 3 00:00:09.920 --> 00:00:16.240 to get started using geometry nodes right away. That means mostly just navigating the UI and 4 00:00:16.240 --> 00:00:21.440 learning the very fundamentals that geometry nodes are based on. To get most of the functionality 5 00:00:21.440 --> 00:00:27.280 that you need into one view, it's best to use the geometry nodes workspace. The workspace is equipped 6 00:00:27.280 --> 00:00:32.960 with a 3D viewport, a spreadsheet editor, an outliner and properties panel, and then most 7 00:00:32.960 --> 00:00:39.600 importantly the geometry node editor. To add a geometry node system on an object, you will first 8 00:00:39.600 --> 00:00:45.200 need to add a geometry nodes modifier. You can add it just like any other modifier from the list in 9 00:00:45.200 --> 00:00:51.200 the modifier tab, or you can click the new button in the node editor, which will automatically create 10 00:00:51.200 --> 00:00:58.400 a modifier for you. That modifier itself is then just a container for a node tree. You can customize 11 00:00:58.400 --> 00:01:04.400 however you want using the node editor. With the data block picker, you can pick between different 12 00:01:04.400 --> 00:01:09.920 node trees that are available in your blend file. That way you can reuse the same geometry nodes 13 00:01:09.920 --> 00:01:16.400 modifier on several different objects. You can also stack multiple geometry nodes modifiers 14 00:01:16.400 --> 00:01:22.080 just the same way as you can stack any other modifier. A modifier just takes the geometry 15 00:01:22.080 --> 00:01:28.080 from the previous one as an input, modifies it somehow, and then passes it along to the next one 16 00:01:28.080 --> 00:01:34.160 as an output. That works the exact same way with geometry nodes as with any other modifier. Just 17 00:01:34.160 --> 00:01:39.440 now you are in precise control of what that modifier actually does exactly. The geometry 18 00:01:39.440 --> 00:01:44.880 nodes modifier is also where you will be able to see the different custom parameters that you can 19 00:01:44.880 --> 00:01:51.200 control the modifier with, just as you can any built-in modifier. And each instance where you 20 00:01:51.200 --> 00:01:58.480 use the node tree in a modifier has its own set of input parameters. The node tree that belongs to 21 00:01:58.480 --> 00:02:05.280 the currently active modifier will be displayed in the geometry node editor. Here you can control 22 00:02:05.280 --> 00:02:10.720 all of the operations that the geometry nodes modifier does on the geometry. Make sure that 23 00:02:10.720 --> 00:02:16.480 when you have multiple modifiers in the stack the right one is selected before you can edit the node tree. 24 00:02:17.680 --> 00:02:23.440 When you create a new node tree it comes with only two nodes that are connected to each other, 25 00:02:23.440 --> 00:02:30.000 the group input node and the group output node. The group input passes in the geometry of your 26 00:02:30.000 --> 00:02:37.120 object coming from the previous modifier and the output passes it back out to the next one. So by 27 00:02:37.200 --> 00:02:43.440 default a new node tree does simply nothing with the geometry, it just passes it along in the 28 00:02:43.440 --> 00:02:49.760 modifier stack. And so if I just cut this connection you can see that the cube disappears 29 00:02:49.760 --> 00:02:56.240 as now no geometry is passed to the outside anymore. But of course the cube still exists 30 00:02:56.240 --> 00:03:02.960 as everything a modifier does is non-destructive. We can just bring it back by simply reconnecting 31 00:03:02.960 --> 00:03:09.360 the input geometry to the group output. Now inside of the node tree you can pass around 32 00:03:09.360 --> 00:03:15.680 the geometry of an object between the different nodes. And this is also how you can make custom 33 00:03:15.680 --> 00:03:22.400 modifications of the geometry using nodes. As a simple example let's just add a transform node 34 00:03:22.400 --> 00:03:29.360 with the shift a menu to move the cube by a vector. Now the cool thing here is that both the group 35 00:03:29.360 --> 00:03:35.680 input node and the transform node output their own geometry that we can use again in the node tree. 36 00:03:35.680 --> 00:03:41.520 So instead of just connecting one of them to the group output I can also join the transformed cube 37 00:03:41.520 --> 00:03:49.280 and the untransformed one together and see them side by side in one geometry. In other words the 38 00:03:49.280 --> 00:03:56.000 transform node does not actually alter the geometry from the group input, instead it creates 39 00:03:56.000 --> 00:04:02.960 its own copy of the data and provides the result of the transformation as its own output. And these 40 00:04:02.960 --> 00:04:09.040 two geometries can be used separately. You can still access both the transformed and the 41 00:04:09.040 --> 00:04:14.960 untransformed geometry and use it however you want inside of the node tree. This already shows one 42 00:04:14.960 --> 00:04:21.360 of the main strengths of the geometry node system over the modifier stack. You can easily branch off 43 00:04:21.360 --> 00:04:27.520 the geometry and have different operations in parallel rather than operating in a single stack. 44 00:04:28.160 --> 00:04:34.160 The same of course is also true for any other node that has a geometry in an output, for example the 45 00:04:34.160 --> 00:04:41.040 join node. It also creates its own new geometry output that we can use just as well as any other 46 00:04:41.040 --> 00:04:47.040 geometry output in the node tree. You can see what data each geometry output contains by hovering 47 00:04:47.040 --> 00:04:53.600 over the socket. So here you see that the result of the join operation results in exactly double 48 00:04:53.600 --> 00:04:59.920 of the data from a single cube. I have shown before that you can use multiple geometry nodes modifiers 49 00:04:59.920 --> 00:05:06.720 in the stack. So let's just duplicate this one a couple of times. This way the result of the 50 00:05:06.720 --> 00:05:13.760 previous one is piped through the same operation again and again. And because all of these modifiers 51 00:05:13.760 --> 00:05:18.880 share the same node tree that they are using, they are all controlled with the same nodes. 52 00:05:18.880 --> 00:05:24.240 So as I make changes to the parameters of this transform node you can see how the changes 53 00:05:24.240 --> 00:05:29.600 propagate to every time that the cube is being duplicated and it affects all of them at the same 54 00:05:29.600 --> 00:05:36.800 time. But actually we are not only creating a single new cube with every step, each time we are 55 00:05:36.800 --> 00:05:43.040 creating a full copy of the input. So there are a couple of extra cubes that are hiding in plain 56 00:05:43.040 --> 00:05:48.880 sight. If I add another transform node into the mix that reveals all of the additional copies of 57 00:05:48.880 --> 00:05:56.080 cubes that we have been creating. The number of cubes actually doubles with every modifier and 58 00:05:56.080 --> 00:06:01.600 so the number rises exponentially. That gives us this cool fractal effect that we can control with 59 00:06:01.600 --> 00:06:07.600 just these two transform nodes. And there you go. That's already your first abstract art piece created 60 00:06:07.680 --> 00:06:13.600 with geometry nodes. And the input geometry can of course still be exchanged for anything else but 61 00:06:13.600 --> 00:06:20.880 the cube. We can for example also get a Suzanne in there. One interesting thing about the node trees 62 00:06:20.880 --> 00:06:26.560 that you reference in the geometry nodes modifier is that they are also regular node groups. 63 00:06:27.440 --> 00:06:33.840 That means that they can be nested as single nodes in other node trees. This way you can make 64 00:06:33.840 --> 00:06:40.000 full use of a procedural system and combine different custom geometry node operations 65 00:06:40.000 --> 00:06:47.040 in one bigger geometry nodes modifier. That also means that sharing geometry nodes modifiers 66 00:06:47.040 --> 00:06:51.520 works the same way as sharing node groups between different blend files and people. 67 00:06:52.320 --> 00:06:57.440 You can simply link or append the node tree from another file and reference it in your 68 00:06:57.440 --> 00:07:03.760 geometry nodes modifier. To benefit from this you can give your node group custom inputs and outputs 69 00:07:03.840 --> 00:07:09.760 that are exposed to the outside. These node group inputs are also what is shown in the modifier 70 00:07:09.760 --> 00:07:16.640 interface in the properties panel. This is very powerful as these parameters can be set differently 71 00:07:16.640 --> 00:07:23.280 each time that the node tree is used in another modifier or another node. These in and outputs 72 00:07:23.280 --> 00:07:28.160 work the same way as you would expect from the other node systems in Blender. You can adjust 73 00:07:28.160 --> 00:07:35.040 their settings in the group tab of the node editor properties. So any geometry nodes node group 74 00:07:35.040 --> 00:07:41.840 can be referenced in the geometry nodes modifier and all of its in and outputs are exposed directly 75 00:07:41.840 --> 00:07:48.160 in the user interface. That makes the modifiers quite customizable and looks very similar to the 76 00:07:48.160 --> 00:07:53.760 built-in ones. And that way you can make your own custom modifiers that you can share between 77 00:07:53.760 --> 00:07:58.960 projects and with others. I recommend you to play around a bit with the node groups that I'm 78 00:07:58.960 --> 00:08:04.400 providing in the files section and the nodes that I've been showing in this video. That's the thing 79 00:08:04.400 --> 00:08:10.400 with geometry nodes. Even with a relatively limited understanding of how exactly they work 80 00:08:10.400 --> 00:08:16.320 it can be a lot of fun and very powerful to build something with them.