Power IK: Ground Node Tutorial

hello my name is Kieran Richie and welcome to the power I came in tutorial so in this video we're gonna take a look at how to make the unreal manikin conformed to uneven terrain so you can see here no matter what slope he's on his feet are always gonna remain completely flat so there's no no ground alignment and I'm real by default same with stairs he's gonna be kind of floating off the stairs doesn't look too hot on slopes with those floating feet so we're gonna use power a K to quickly and easily get rid of that issue okay so I'm gonna hit stop we're gonna jump into his animation blueprint and it's really important to think about where you're putting the ground alignment node so we could stick it right here right before the final poses output but you don't want ground alignment taking place while the characters in the air so in the case of the third-person mannequin here he's been set up with a state called idle run which pretty much encapsulate all of his behavior while he's on the ground and then he has these jump States where he's in the air so we don't want power decay pulling the character back onto the ground while he's supposed to be in the air so we're actually just gonna put the ground node in his grounded state here where he's an idling and running so his the state's very simple he has a little blendspace this can of course include any arbitrarily complicated system that you want but really what you want is while the characters on the ground after the final grounded pose has been generated and before its output this is where you want to stick a power aka ground node okay so I'm just gonna make a little bit of space here right click and tell you the power okay and we're not gonna select the solver we're gonna select the ground node so the ground own kind of encapsulate Stu solver and takes care of all the raycasting for you all the things that you need just for ground alignment okay so by default it comes in with a character root set to pelvis which in the case of the unreal mannequin is the bony one so you want to select that control sorry that bone that controls the top level of the character okay so this is usually names like pelvis or hips or something like that and if we select the power kick ground node you'll see this foot array our feet or a okay so we need to add two to that so I'm gonna click twice on there uncheck expose because we don't want we don't really need to use pins for this and then we can see these these two feet array members right here so I'm gonna pop those open you don't usually have to mess with these values too much they kind of come in with good default values all you really do need to specify is the bone name so we're gonna pop back to the skeleton to find those bone names and I'm gonna run the power I K on the feet so foot underscore R and foot underscore out okay you can right-click also and copy those names and you can paste that right in there so foot L and what are we're gonna hit compile and now after compiling you should see these yellow diamonds on top of the foot locations if you don't see the yellow diamonds do check the output log make sure there's no errors here related to a misspelling of the bones the yellow diamond indicates that the solver has found the bone and it's set up correctly okay so let's go ahead and hit play and see how we're looking now okay so the first thing you're noticing is of course that our character has floated up into outer space so by default the brake casts that are going to be finding the ground location will collide with anything including the character capsule so in this case he's kind of just walking on top of his capsule you can see the shadow there so we're gonna stop here go back into that power acade ground node I'm gonna close the feet section and we're gonna look for ground settings under here we're looking for around collision and I'm gonna set this to a custom collision channel which I've created called iCade trace and I'm just going to take one moment here to talk about this collision channel and what I've setup on it so if you go under your project settings under edit project settings go to collision you'll see trace channels so you need to click new trace channel I've already done that i've called it i kate race and then you need to make sure that that trace channel is set to ignore two things by default so you need it to ignore ponds and character meshes okay so if you pop that open you'll see that it's set to ignore I keep trace channels on both character meshes and points okay now we've set that as our collision channel on the power ik a ground node hit save go back here at play and character is no longer trying to walk on top of its capsule and it's already starting to conform to the ground so in cases where the character goes off the ledge is going to transition out of that idle run state and into the falling state and so you can see that it no longer tries to pull it on to the ground but we are getting kind of some issues there where you can see it kind of goes on to the ground a little bit his feet are sinking into the ground so we can start to sort of fix up some of these things so I'm gonna jump back into the ground node I'm going to take a look at the feet Delta smooth speed so that's the speed that the feet will adapt to the underlying terrain so I'm going to turn that up to 300 I should prevent you from dunking into the ground and then we're also going to take a look our collision settings all right now we're gonna take a look at the the slope settings okay so there's a lot of stuff going on in here you'll need to be checking the documentation to get a full description of everything that's going on here but it's essentially broken into sections where you can choose to scale the stride of the character to have the character leaned into an out out of uphill and down hills you can have a counter lean bone so this is licking the kit in the case of bipeds you know if they're going downhill they'll typically tilt their head down to look down the hill and vice versa that's what counter leaning means you can also move the route the root of the character up and down depending on the weather they're going up or down to hail or on the side Hill in this case what we're gonna do is rotate the foot to the ground and I'm gonna offset the feet a little bit to get them out of the ground so I'm gonna hit compile go back here and now when we stand on on the hill you can see our feet are conforming to it and that offset has pushed those feet out of the ground so that's just a static offset that you'll you will have to kind of butyl a little bit right now it's set to four centimeters we set that to zero and compile and go back you'll see his foot is now sinking back into the ground a little bit I found that for the mannequin the default setting of four tends to be enough to kind of get a good result when it comes to the rotation you have separate control over the pitch and roll where pitch is sort of in the direction of the hill and roll is sideways I find that a value reducing the roll helps prevent the feet from kind of looking like the ankles are breaking but there you can see now he's fully conforming to the to the uneven terrain and it works just fine on moving collision as well so from here you could go back into that ground solver node start playing with the leaning settings and getting a good result there's nothing that prevents this ground node from working with quadrupeds or even spiders any number of limbs you just keep adding to that list of feet and let power I kind of take care of how to move the the whole character to conform to the underlying terrain so the key features here are filling out your your foot array with the with the correct name of the bone make sure your character route is correct check that Delta smooth speed to keep the feet performing to the terrain quickly enough so they don't sink into it go ahead and play with these lean settings if you're feeling fancy and do make sure that you set that collision channel to something appropriate something that is blocking or is not that's ignoring the character capsule so Isola is to set up the power IKEA ground node thanks for watching and

Channel: Power Animated Inc

Views: 10,736

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Id: g1FgBDIA2zA

Length: 8min 25sec (505 seconds)

Published: Sun Jun 21 2020