Inflated Objects using Geometry Nodes

I'm going to show you how to use geometry nodes to take any mesh and instance a bunch of inflatable balloons in it to begin I'm going to create a new project I'm going to select everything delete it and I'm going to start with a Taurus so this will be the mesh that we're using in this tutorial but you could obviously change this later I'm going to create a new geometry node so I'll just label it balloons I'll pin this and we want to instance a bunch of objects inside of here so to do that I'm going to do a mesh to volume and then I'm going to do a distribute points in volume and then I'm going to instance on points not two points there we are and I'm going to do an icosphere you could use different geometries but I like icosphere just because it creates this um pretty evenly distributed sphere or verts that are pretty evenly distributed in that sphere and let's just make this a little a little smaller for now we can actually put that into a value because perhaps it's something we want to animate or change later it'll be easier to tweak like so so we have the basic objects that will be inside of our mesh and we can increase it but there's a few issues so basically each of these will basically be balloons that are going to have cloth simulation on it and if they're overlocking it can actually cause some issues that the blender cloth simulator kind of creates all these glitches with so I like to add a merge by distance on the points that we distributed and we can just crank this up so we can create some space between the instance objects and it's still kind of random it's not like perfectly uniform and we can obviously change the seed and see different variations of it but for now let's just keep it like this and we can see how it is later all right so now that we have these we basically want to add a class sim on it and to do that I will just go into here and I'll click cloth and I'm going to by default just kind of go into the field weights and set gravity to zero and we want to add pressure I'm going to make that 200. and we're going to be tweaking these values a lot so I'm going to try and help you understand how to debug it yourself because with blender and cloth you can often encounter glitches so I'm actually going to up the quality of the the collisions to 10. so to me this is quite important because we're going to be filling the mesh and the quality of steps here maybe we put it to 10 maybe we keep it at five we'll see and the last thing here is uh once we start inflating it you'll need some sort of geometry to conform into so to do that I'm going to create another Taurus I could also have just duplicated the previous one and I actually want this to be a bit wider so I'm going to do something like that and let's just double the segments and the reason I'm doubling the segments is so that when the balloons inside of it are pushing against the wall we won't see like really hard edges uh to where it's conforming to this this geometry we could even bump it up further if we wanted something like this all right we basically need to take this outer Taurus which I'm actually going to change his visibility so we can see inside of it I'm going to set this to wire and we're going to want to go into edit mode select all the all the quads and then do a invert or a flip flip normal so now that the normals are flipped um if we Press Play We're actually not seeing anything right now and that's because if we go back into these spheres that we generated there's several issues one cloth Sim and geometry nodes for them to work the cloth needs to be put afterward but also these are just instances right now so we need to actually realize those instances now we're going to start to see the move so you actually see it moves out of this this uh Collision object and that's because we didn't set it to Collision yet so if I set that to Collision and then I click play you'll see they'll bounce inside of there now let's go back into our inner balloons and there's several things we want to look at um one is the distance in which the Collision is so but I like to have both of these always be the same if we want the collisions to be really close we could do like 0.01 for now I'll just keep it 0.05 I think having a lot a bigger distance actually prevents some glitches with the cloth Sim we could always up the pressure so let's just say two thousand and it instantly glitches out because it's way too high so you can see uh it's it's all a balance so I'm gonna just keep it at 200 and the main thing I'm going to keep tweaking is this tension so the tension is basically the amount of force it wants in order for it to keep its own shape so if I set that to five and I click play you can see it's bigger than it was before let's say I set it to three and it's starting to work so it's it's all a matter of tweaking let's do like 3.5 and that it's actually looking pretty good the only thing I don't like is that I think the the objects inside look all a little too uniform so I kind of want to maybe tweak let's go back to here tweak um how we're generating these maybe this is actually too high let's try and do something like that this one's falling outside of the outer sphere a little bit so let's just see if that creates an issue looks like it's working pretty well and one thing to note is if you were to do subdivision four all these cloth values need to then be changed so it is very dependent on how many vertices your your cloth your initial cloth geometry is using so I like to keep it low because later I can always subdivide it and make it look really smooth so we get back to here I actually think this is looking pretty good and we're going to want to do a set material which we'll create shortly and we also want a set smooth so there's a few things one because we had that .15 distance on the Collision that you get to see all these like little gaps in the geometry So to avoid that I like to do a well first I want to do a subdivision just to get it smoother and then I want to do a solidify and with solidify I can actually go in the inverse Direction and I just go kind of like a minus 0.0 I don't know 0.06 let's say maybe we can even go lower try .05 0.05 [Music] and now it looks like really condensed balloons within this original Taurus object and let's create a material I'm going to show you one last thing just in terms of materials I'm going to create one here just call it balloon set it here and I'm going to put the Shader editor over here so it would be let's just put one more light in here as well so let's put a sunlight put it at three all right so it's very easy to just like put the material all the same for each sphere but we may actually want to have the Spheres be random colors and if you've realized instances you're not able to do the object info node and set it to random so this will all just be white so if I do the realize instances which we do need to do because it's a cloth Sim I'm going to want to add a capture attribute and I will drag this attribute here and because we're doing it before the instances are realized I can set this to instance so for each instance I'm capturing this attribute let's put it here so you can see a little bit better and what do I want to capture I can do a random value and it could be whatever I want I think zero to one makes sense here and under the geometry node over here output I'll say Rand I can basically type whatever I want there and then in the Shader I can do a tribute type Rand and we're going to have a bunch of random well actually a zero to one so it's a little hard to see but I'll show you with like a color ramp and we can set this to like HSV put something in like that maybe we'll put one more color in here and now we have a bunch of random colors within our inflatable objects so you could add this to any mesh the key is to just create a outer Collision mesh generate your your points inflate it with the cloth and then do a little bit of tweaking and shading to make it look good if you like this tutorial drop a like drop a sub I'll have this file up on my patreon thank you for watching

Channel: Robbie Tilton

Views: 52,431

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Id: IofA3OA3eIk

Length: 10min 25sec (625 seconds)

Published: Fri Feb 17 2023