Easy Rigging in Blender 3D : IK Rigging

Hey everyone welcome to this Nekomatata tutorial this tutorial is an introduction to inverse kinematic rigging also known as ik rigging using Blender 3D if you're completely new to ik rigging in this video's for you this video is meant to teach you more concepts that you'll need in order to create this rig i'll be going over the difference between forward and inverse kinematics when to use forward kinematics versus inverse kinematics how to create an ik bone chain and how to enable and disable ik in order to easily improve your rig the term inverse kinematics seems pretty big and scary but it's actually really easy to learn let's get started forward kinematics vs. inverse kinematics what is the difference first let's see the difference I'm going to create the same pose with these two bone chains watch for the difference in how i create the same pose did you see the difference on the Left we have a forward kinematic bone chain this is your default bone chain behavior where the pair bones tell their children what to do typical the orders go one way and our past forward down the chain that means that the last bone is influenced by everyone else and the first bone takes quarters from no one does it have no parent the ik chain works differently the first and last bone work together to tell the bones in between how to behave you'll notice that I'm moving an extra bone in order to manipulate the last bone in the chain this bone is called the ik target it's a helper bone that must exist outside the bone chain if I inspect the bone properties you'll see this phone has no parent in technical terms the target cannot be part of an ik chain because it causes an infinite loop that the ik solver can't solve I like to think of a target as a bad boy that the last bone wants to run off with the last bone goes wherever the target goes and the concerned family just kind of follows along easy right that's all you need to know so let's talk about once use forward kinematics and when to use inverse kinematics the arms are a good example of a set of bones that will switch between inverse kinematics and forward kinematics often if you have arms that are swinging and waving you might want to use forward kinematics if an arm is reaching out to grab something or let's say your character is doing a push-up then inverse kinematics would be great to use if your character is sitting down and swinging their legs from a chair forward kinematics if your character is doing squats inverse kinematics it's all about picking the easiest method to get the job done that's it next I'll teach you how to make an F k chain and an ik chain just like the ones you see here to create this FK chain add a new armature by pressing shift a and selecting armature or if you're already in the armature press shift data out of bum scale the bone select it and press W to subdivide twice select the bones and press alt f to flip their direction this isn't a necessary step we simply use alt f2 flip the direction of our bones our chain is now facing down instead of up now you have an FK chain with four bones remember forward kinematics is a default behavior so we don't have to do much to create an FK chain next we'll create the ik chain press shift a to add a bone scale the bone select it press W to subdivide twice select the bones and press alt f2 slip their direction now we'll add the ik target select the last bone in your chain press e to extrude the target select the target and clear its parent by pressing alt p or go to the properties panel and clear the parents there next I'm going to rename my bones first second third last and target in order to stay organized in order to get inverse kinematics to work we need to add a bone constraint to one of our bones in the chain toggle into pose mode select the last bone and the chain in the properties panel find the bone constraint tab the icon looks like a bone with a chain next to it click the button that says add bone constraint select inverse kinematics under the tracking category under target select armature and herb own find your target bone look you did it you created your first ik chain there is an easier way to add the ik bone constraint first select your target bone then select the bone that you'd like to add the constraint to press shift I and this will add the inverse kinematic constraint to the selected phone one important setting for ik chain is the chain link go to the ik constraint in the properties panel and find the box that says chain length if the length of 0 and these the ik chain will go all the way up until it finds a loan with no parent you can manually define how long do you want your chain to be by making the number greater than 0 next I'll explain some common ik issues and how to solve them if your bone chain is completely straight and you try to move your target into the chain the chain might freeze up the way to fix this is to kind of jiggle or tweak one of the bones inside the chain so that the chain is not completely straight another common issue is getting your bone chain to bend in the correct way by default your chain might Bend left when you want it to bend right or vice versa in order to fix this will need to add a pole target start by adding another bone to the armature move this bone out to where you want your chain to bend this is a helper bone so just like the target bone make sure it is not related to the main chain so clear the parent name the bone something useful like full target for the main chain you'll want to adjust the bone roll a bone roll is sort of like a rotation of a bone around its core select a bone and edit mode go into the properties panel under the bone tab and adjust its role make sure that the role for each bone is set to zero now we're ready to set our poll target in pose mode select your bone with the ik constraint in the properties panel under bone constraints find the ik constraint and sets the poll targets to the bone that we just created sometimes you'll have to adjust the poll angle right now by default the poll angle is set to zero sometimes the default won't work for you and you'll need to set it something like negative 90 90 or zero I all set mine to 180 now when you move your target bone the bone chain will always point in the direction of the poll target there's one more thing that we can do to improve the setup most of the time we want our poll target to move with our target bug let's go into edit mode set the pool targets parent to the target bone and then go back into pose mode now the pool target moves with the target bone it'll also follow the rotation of the target bone this is really useful when you're animating the last thing I'd like to talk about is bone constraint influence if we go to our inverse kinematic bone constraint will see an influence slider this slider can be set to any value between 0 and positive 10 means that inverse kinematics is disabled and one means that it's turned all the way on if it sets is somewhere around point 5 it means we're halfway between forward kinematics and inverse kinematics i usually don't set it to point 5 but it's nice to know you can so why is this influence slider so important it's useful because if you're animating you can set keyframes on it and this means you can switch between inverse and forward kinematics during an animation set an animation keyframe on your timeline by right clicking the influence box and choosing insert keyframe well that's it for this tutorial in the next tutorial I'll be showing you how to connect your armature to your mesh thanks for watching peace

Channel: Nekomatata

Views: 134,010

Keywords: blender 3d, rigging, armature, bones, inverse kinematics, forward kinematics, fk, ik, game rigging, rigging for games, unity, unity 3d, tutorial, 3d rig, 3 skeleton, 3d armature, blender, blender tutorial, introduction, easy, simple, pole target, beginner

Id: 1-5ZR45y9RM

Length: 9min 51sec (591 seconds)

Published: Thu Apr 13 2017