Simulate hair with Geometry Nodes Hair System in blender

hey guys thanks for tuning in and in this video I'm going to share a method on how you can simulate or rig hair with the geometrical hair system [Music] the way the whole process works is that you basically have your base mesh which you can simulate rig or use a shape key on in this case I have a cloth and when you do that you can apply the geometry nose modifier which can change this into hair strands in this case and change my into braids that's in very simple terms how it works if you understand your machine nodes and you know how to get your way around it you can create this on your own foreign setup that turns the polygons into hair strands I know it may look confusing especially to those who haven't used geometry notes that much but the good thing is that with the add-on you have access to all these controls and even the ones from here in the end panel up here so let me give you an example you can turn this on from low poly to high poly do the same for this and you have access to a bunch of all these controls most of these are self-explanatory but I also include a manual you can read through to understand it a bit more so for instance here I can reduce the frequency increase the width of the braids and do so much more it's all included here so yeah I'm just going to walk you through and how to install the add-on and get started [Music] first of all download the zip file there's a link in the description don't just install the zip directly you have to extract the files first and then there you'll find the addon bgen.py the blender file regen samples and a PDF B gen manual regen.py is the add-on and you can move it into wherever you keep your add-ons in blender go to edit preferences add-ons install then locate the folder where you kept your B gen or py and after that click on it and install okay so the B gen samples files contains all these hairstyles and some hair clumps here too all of them have the correct geometry notes attached to them and also some of them have the cloud modifier and are ready for simulation the hair also has the materials the special material created for each hairstyle so let me just switch this to the rendered view so in the materials here it's B gen matte underscore zero one these controls can change the color so this one controls the roots up here and the second is towards the tip and you can change how the gradient is affected you can move it up and down like this and you can also change the color make it darker brighter and all that so yeah each hairstyle has their own materials attached to them and some other references of some clumps you can use in your own projects they're already made here uh I'll advise you to just come here and you know append either of this or you can append everything into your own project and start using it or you can just take any of the hairstyles you think is good and you see all your characters you can also edit and build up on them and if you aren't too clear on certain things you can read through BJ and manual and it has information on how to install on how to use it the best ways and also has information on the different attributes in the panels so you can just read through if there's something you don't quite understand and this hopefully should be able to get you up to speed if you don't understand anything or you have some suggestions or you want to you know reports of bug or something just message me on my socials uh that's down here and yeah okay now that you're all set up let's see how to use the hair system effectively the best way to use the add-on is think of it like you're creating hairstyles with hair cards hair cards are used in creating her for video game characters where the hair textures are applied on the flat polygon and then arranged in different ways for different styles this system is like using her cards but instead of hair textures you have hair strands there are two main ways of making hair with this add-on the first is the vertex the strips method and the other is the linear mesh method don't need curves or hair particles use the vertex or strips method if you want to create longer and more Dynamic moving hair so we're looking at dreads braids or long curly clumps that flow in the Wind while creating this extrude a line of vertices [Music] but as you can see after applying the vertex strips the weight painting is out of order so the way to fix this is simple go into edit mode select the first vertex on the string shift s cursor to select it then select everything go all the way to mesh sort elements and coarser distance and everything will be sorted so when you check the weight painting again should be linear you need the vertex distributes modifier to be the first in the modifier stack for the hero to be created the linear mesh method is better for shorter hair that might not need so much movement the topology of the mesh has to be clean and have linear Edge Loops you don't need the vertex or strips modifier for the hair to be created just Mark the edge of where you want the hair strands to start and you're all set okay I'm going to explain how the hair stimulation works with this hairstyle first of all you're going to want to put all this in a low pulling mode and yes when you're creating the hairstyle put all the strands that you want to be simulated or the long strands in one group so like I've done here I've put all the strands in this group hs2 so in the hair Sim section you're going to want to come here you can copy the name of the group using the shorter name so I don't if I want to type it I don't have to do too much I can just try to type hs2 we have it the next next thing you're going to want to do is put your Collision mesh in its own collection and of course add the Coalition modifier to it which I've done here and the setting I use here is puts a thickness on 0.001 I always do that I don't know why I just get better results with that yeah and here you're gonna put what collection you have your Collision mesh in and in this case the head is in her Styles too it's going to come here and copy it paste so while we're doing this is because all this values or parameters affect all the hair strands in this collection so I don't have to go into each Strand and you know come to the physics Tab and change the steps I know that's manually I can just control everything from here so yeah let's say we want to give this the quality that's the quality steps you want to change it to three like it is here and I press execute see this is three if I click change to another one it's also three also three so yeah so you can use this to quickly just experiment with what values work best with the simulation okay the next thing is the vertex strips which is below this in the hair Sims tab in the vertex strips you can control how large you want the strips to be this affects the simulation some points too so if you want it to be really small you can affect this or if you want it to be bigger I included this because simulation adjusts vertices alone uh it doesn't give accurate properties and you can't use collision and just single vertices that's why I added the vertex for strips in this method okay so if you go into weight paint mode the way paint is controlled by this float curve down here so if you want just the roots to be the pin group you can put this here and yes when you've chosen the weight paint you want it affects every other strand that has this vertexure strips modifier so this one has the same this one has the same if I increase it increases for all of them also yeah and this group is mainly for the paint groups and the Collision groups and all that and the nice thing about this is when you hit execute it executes the weight Paints in all here for the pin groups so if I go into the physics again and I go down to shape and pin group let's say I remove this see as I press execute it comes back so it works here and it works here for the Collision too and let's say I remove the Collision here and see I have hairstyles too as a collision and I click execute comes back here for all of them so yeah uh the next thing you're going to want to do after weight painting gets in the correct weight for the hair strands is to test the simulation I'm just going to turn off the wind for now so if I play just falls down there's nothing effect in it so it's going to go back uh I'm gonna select this everything is parented to the hair cap okay so I'm just going to select the hair cap and the mesh play and I can move around and physics gets affected it's gonna move back here do it from the side press play see oops around and it gets affected so if I pause here I can go into the Shaded mode and turn off low poly here and here and you see so you still have the geometry notes on top of all this but because we applied the cloth modifier before it it just seems like the hair is the one being simulated now obviously this addon doesn't do magic it's still going to be extremely slow because see you have 2.7 million vertices here so it's still kind of tasking as we task in on lower end computers but the good thing is you can bake the movement of the cloth modifier so if I go here just turn everything back to low poly and let's activate the wind okay let's see if the wind works I've already put some values uh oh by the way these are some values that work well for me I put two thousand uh if I just play you can see how the wind affects it uh forgive the hair I didn't just I just made it look good from one angle just for demo purposes if you want to you can add more hair strands at the back to make it full if the animation needs it so with the force field activated I can go into the hair seams again and I can bake physics so all the movement that has gotten from the force field can be baked into the cloth modifier so I'm just going to see if the values are all good like them okay nice I'm Gonna Bake all physics just wait for it to go through and we're good so if I play it's playing really well say 25 frames so you have this embedded uh I can switch it back the thing is if I switch it back out of low pulley it's still going to be slow and that's because it's moving thousands or hundreds of thousands of vertices or even millions of vertices at the same time so it's going to be slow see it went back all the way down to five frames per second and you would want to get the animation right with the low poly then when that is all good and the simulation or the animation is correct you just turn it back to high poly and exports the animation or render the animation sorry and that's the way it works so I'm just gonna look at it or pick a frame that we like with some nice movement and we can just turn it back [Music] and yeah so yeah so this is seemingly good um I guess hair simulation we're kind of fake in it here but I mean it's the only option I have discovered at the moment um I'm sure it's gonna be better eventually when blender develops the actual simulation for the geometry notes but for now this is the system I've created hope you like it and yeah you can use it in a very creative ways um and please if you find a way to use it that's really interesting for instance if you rig your hair uh just share with me on Twitter my Twitter handle display somewhere in the screen okay thank you so much for watching I really appreciate it and thank you for showing interest in this add-on I have created a time lapse for the creation of this hair and I'm going to link it after this video I hope you enjoy it if you have any questions you know just ask me on Twitter or on Instagram and I'll be happy to help and yeah thank you so much have a great day [Music] foreign [Music]

Channel: munorr

Views: 19,541

Keywords: blender, blender3d, geometry nodes, blender hair, 3d character, 3d animation, 3d art, blender art, blender hair tutorial, braids, blender tutorial

Id: q4uzLyjjxFU

Length: 14min 29sec (869 seconds)

Published: Fri Mar 24 2023