Unreal Engine Cloth Physic Settings Explained

all right guys it's me again i'm back with another video it's been a while uh i've been caught up with some things so today i'm just i made a simple dress really quickly and uh put it in here uh using uh marvelous designer and adobe substance painter so let's get started i'm gonna explain to you all how to uh configure your cloth settings so first we're going to right we're going to make sure section selection is enabled so click that if you don't have the clock clothing window go over here check this it'll come out in a window like this what you're going to do is you're just going to drag it over here that's what i did makes it easier go to activate cloth paint with oh i'm getting ahead of myself so first off what you're going to do is you have to make a uh you have to make clothing data and then you have to apply it to it so first we want to create clothing data we're going to call this address we're going to create it we're going to right click it apply the dress clothing data this will take a a second or two after it's done select to this and go to activate clothing paint cloth paint and uh i am on the mesh by the way so after you've done this we're just gonna go to gradient we're to set this 0 to 30 is uh seems to work for me just click anywhere on the dress up near the mid or top section then hold down control and select a bottom point and then press enter it'll create the gradient for you go back to brush set the paint value to zero and then uh also what i did is i changed my radius to five on this if you didn't see that earlier and you're gonna go all around the the upper part of it make sure that's all pink and we're going to go all the way around this and actually it might actually make more sense if we set this to like 20 nah yeah 20 20 is fine and just do all of this and then we're going to go to smooth we're going to set this to a value of about 0.8 and smooth it until it gets up there around that point if you want some of this to be higher you can turn your brush down and you can manually oops you can manually smooth it like that that'll probably probably be good we'll see so after you've done that deactivate it see what it looks like you'll probably have issues with clipping that's all right we'll fix it and there it is okay it doesn't look like we're having any clipping issues it does look a little funny right there but that's alright what you could do is you could just go back into paint mode and with a soft brush maybe about 15. you could just lightly paint that right there and that right there and then go back to smooth and smooth it one more time make sure it didn't mess up the back too much that looks fine we'll deactivate this and see what it looks like that looks better you can do the same thing for the front part right here if you need to so we'll do the same thing here and do that and smooth it might need to redo this whole thing like how we did it so i might use 10 this time and try not to undo what i did right here and then i will go back to smooth and smooth at once and that should be fine now we'll undo this and that looks better and still no clipping oh wait there's some clipping right there so we're gonna fix that you can go to uh actually let's fix it using the cloth settings so go down to clothing and down here at the bottom where you see collision thickness you can try turning that up to two and that what that does what i did just then was the spacing between the physics asset and the cloth uh that's it's gonna add uh extra spacing between the physics or yeah between the physics collision and the cloth so that that's your physics uh collision right there that's what it treats this physics collision is your uh physics asset so now what we're going to do is i'm just going to turn this resolver up because i think it's it tends to make it look better uh and this resolver is just a frequency of the position solver lower values will lead to stretchiness bouncier cloth so that's what that that does that'll make it stiffer and the stiffness frequency frequency for stiffness calculations lower values will degrade stiffness of constraints so if you turn this down it'll loosen uh the constraints between those collision physics and let me show you what that looks like so if you go to character go to clothing go to self-collision radii and then go to activate and deactivate cloth paint that you should see it and just give that a second oh well there i missed something you have to to see this you have to turn on self-collision radii that does have a small performance impact on it and we'll just turn the self-collision uh stiffness up to one and if you didn't catch that you see how it looks right there and that's uh for the self-collision stiffness but we'll probably just leave that at zero and then deactivate and activate or activate and deactivate cloth paint and it should do it this time okay it's kind of hit or miss for me on this let me see if uh doing that we'll uh and i'm not real sure what causes this but sometimes it doesn't want to show us the uh there it goes so apparently you have to have self-collision stiffness turned on in order for it to be activated and then you have to activate and deactivate your cloth paint so you have to have at least self-collision stiffness turned on i'm not sure about self-collision radar radius but i'm assuming so since without any radius you won't be able to see it so that's probably okay what you want to try to do is avoid any kind of overlapping like you see here but if there's a little bit of overlapping i don't think it's too much of a big deal you could turn it down to about 0.9 uh or even 0.5 uh that's too small we'll turn it down to 0.8 and that should be fine so that should greatly reduce the overlapping that you get now obviously that's self-collision and that's talking about uh these little orbs you see here so the spheres or orbs whatever you want to call them uh when it is what the physics are calculated based on so when you see the self-collision radius that's the size of those orbs and this is the stiffness of those orbs uh which uh stiffness of the spring force that will resolve self-collision so that's just that's like how stiff the spring force is so if you can imagine a spring and and one's real loose uh so it's so it's compressed easier and the other one uh is harder to compress down then that's basically i believe what they're talking about here and a lower one will will make it looser and a hot a higher one will make it stiffer so one is normally okay for me sometimes you might want a self-collision radius larger than this it depends on how detailed your mesh is so down here on the friction that's basically like how much friction it has when it rubs up against uh another sphere so [Music] sometimes turning that up to 0.5 will make it look better during animation like how it moves during the animation so right here this is linear drag and angular drag most of the time you'll see that the pre-made cloth settings on other assets are set to zero that has to do with the wind like uh and down here on tether stiffness uh that can be or a tether limit i should say that's how far uh they can separate and if you have issues where you have like a sleeve or a jacket on her and uh so if this thing had sleeves and you had issues with uh parts of the dress attaching itself to the sleeve you would use the tether limit to fix that and normally you don't have to turn the tethering limit up above 30 so about a value of like 20 to 30 will normally fix those issues where it's sticking to the sleeves uh turning tether stiffness up to also has an effect on stuff like this i believe so let's see if i turn this up to 15 it doesn't seem to have an effect because that's stiffness right i'm uh still thinking of limit here so when you turn the the limit up it actually uh it actually loosens it but that will fix some issues that you have it also i believe make it bouncier because it can separate farther so you can also turn it down and if you do you might get stuff like this so keep that in mind even 0.9 has a an effect on it so we might do something like 1.1 and we could turn the stiffness up but you probably won't see its effect unless uh you turn it down way far like that or it's or it's being animated so keep that in mind as well anima drive spring stiffness that's if you're using an m drive i'm not familiar with that so i'm not going to go into it wind drag and lift that's pretty self-explanatory the vertical constraints horizontal constraints bend constraints and share constraints all have an effect on how these particle spheres move uh and how stiff they are how stretchy they're gonna be i normally don't mess with those but you can uh it can have an effect on how the cloth looks during simulations if you need to preview it you can go over here and select an animation to see what it looks like and honestly i do not know i do not know how to turn that off so but you see there's something here that's i don't know and this is another reason why it's good to uh look into this because you can get issues like this with your cloth where when it's simulating physics it may be colliding with your physics but i don't see any physics asset right there that's colliding with it so it may be that you just need to adjust the uh if you oh here you go if you need to remove that animation that preview animation you can do that so we're going to go over here to character we're going to go to clothing and self-collision radii we're going to turn that off and this right here is where it was doing that at and i see why it's doing that now remember i added i increased it right here but i left a space right here so [Music] it's it has less physics right here more physics right here and more physics around it and that's the reason why it's doing this so when you're adjusting that stuff you need to be mindful of that and i believe we used a value of 15. so we're just going to fill that in and that should fix it and we should probably do the same right here on the sides and right here and right here and then we're going to go to smooth and smooth it twice and it did mess with this up here a little bit so maybe we'll go back to the brush turn the value back down to zero and go around the edge you don't have to be too shy with with this just make sure that you don't overlap with the parts that you don't want it to affect greatly and then what i'll do is i'll go back down to smooth and i'll smooth it once maybe twice more let's undo that last one and what's happening here is it's making the scene brighter you can go under post processing right here to fix that and turn post processing off that's a neat trick too uh you might want to keep in mind you can also just go under this and adjust the brightness of this or the intensity of it and it only affects this scene right here where you're optimizing this now back over here your dampening force uh is that obviously it's the definition of the particle motion per axis and that is basically how quickly it will stop moving so if you have uh i might have it backwards but if you have a high value i think it will stop it faster the cloth will stop bouncing around faster if you have a lower value i believe it will stop it'll bounce around longer after a movement the gravity scale you can turn the gravity up on your cloth if you want it to have a heavier feel to it or you could even turn it down so it has no gravity also i do believe you can uh you can tweak these values in real time through your blueprint so keep that in mind i think this is pretty much it so let's uh go ahead and test it out here and see how it looks so obviously we have some weird stuff going on here it looks like when i imported my mash it there was a little piece that got missed somewhere and that's probably what's causing a lot of that so what we'll do is we'll come back in here and see if this thing has any physics on it and when i go into physics mode it actually doesn't even show up so i have no idea what that's coming from let's see this min and max view value is uh the minimum value that represents the min value represents uh y and the max value represents black so if you turn the black value up you'll and i might have that backwards so let's say if i turn this up to 50 yeah i think the minimum value stands for black and the max value stands for white so if you want a wider range of gradient then you would turn this up but just know that it's going to affect everything cloth physics wise it's this isn't just for the one that you have selected turning this up turns it up for everything so that looks a little bit better we have some clipping through here right here uh and the front of it still looks a little funny let's see not so much when it's moving around but when it's sitting still it kind of looks funny you could adjust that a bit now if you want it to not look like that let's see let me get out of cloth painting mode so it looks fine in here see this is one of the weird things about unreal's uh cloth physics system is it might look fine in here but when you go into the viewport it looks different so that's why it's normally good to have to try try this stuff out these animations and try to see how it's messed up and tweak your cloth settings accordingly so i might go into a walk and what we might do is we might want to make it stiffer let's try this what's going on here that's interesting it bugs out like that sometimes their uh cloth system isn't 100 perfect you can make it more accurate if you go to accurate and as you can see here use use updated use updated wind calculation for envy cloth base solved taking into account drag and lift this will require those properties to be correctly set in the clothing configuration but we're going to use legacy accuracy would probably not be something you would use in a game and you can see how having it set to three is just a little bit too much there even having a set to two may not be desirable so what we will do is try turning this down a little bit and i probably shouldn't have done that that normally takes a a good minute to uh complete been avoiding uh saving it for that reason let's see what it looks like so we'll go back in here and we'll turn our radius our collision radius up to about two and turn down let's see the stiffness and we will see how that looks we'll see how it looks in motion stuff like this has to be adjusted on a basic base uh if you go to activate cloth paint you can adjust the smoothness of this and the and this as well as i showed you before stuff like that is kind of hard to avoid if you see stretching like that it's normally because the cloth is has too much physics at the end of it and it needs to be redone so if you have stuff like that you would want to go back in here and you would want to make that uh would want to make that darker than what it is so you maybe use a different uh value on it i'm not going to do that i think this pretty much sums it up uh if you have issues like that what i showed you just there i think let's see we can turn up the tether limit i believe that will help let's deactivate this let's see if that helps yeah so it helped a little bit as far as self-collision you'll have to tweak these self-collision values to try to get what you're wanting so that it's not colliding with with itself see if you turn that up too high and you have your self collision too big then it's going to do that it's a balance you have to try to find here you could even try turning your friction up but it probably shouldn't be a one just to let you know and i think turning it that's friction up to a one may made it might have made it a little worse but it's looking a little better now the let's see i'll just turn that back down to 0.1 and see how what kind of a difference that makes in the way the cloth moves so it's not even really noticeable but if you're looking closely you'll be able to tell that there's a slight difference in the way the cloth rubs up against itself but yeah that's pretty much it guys uh i'm not gonna go into too much more detail on that uh like i said uh stuff like that this is probably caused by the fact that i did a really quick job on this just to get addressed so that i could get it imported and show you all this so if you would just ignore that issue at the bottom of the dress when you're doing dresses and marvelous designer you'll get bugs like that you have to learn how to like what you can and can't do for example this dress i didn't make it i just modified it so you can see this dress actually has two layers i took the second layer off because inside of unreal when you're doing physics it's going to cause issues also if you have a seam around the bottom of the dress like this it needs to be on the same material as this as the other parts so all this down here would need to be part of one material i'm not gonna go into that right now but maybe later i'll do another video on that i think i'm gonna do an entire course of from beginning to end for uh marvelous designer to character creator uh to unreal and i'm gonna do a full episode where it goes into physics and everything and i'm gonna put it into a playlist and i hope this helped you guys and i'm gonna go close this right now because i'm i've already made this video too long

Channel: Unreal DevOP

Views: 36,450

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Id: NIwU2WJeco0

Length: 31min 19sec (1879 seconds)

Published: Fri Dec 24 2021