How to Setup Arm IK Rigging (Blender Tutorial)

in this tutorial i'm going to show you how to do arm rigging using inverse kinematics in blender now if you'd like to learn the complete process on how to model and rig a basic character then i have tutorials on basic character modeling and basic character rigging links in the description if you'd like to check out those tutorials and if you'd like to use the same arm model that i'm using then i will have a free download of the project files for this tutorial with the link in the description and you can use the project files to follow along or you can use this on your own character if you've already created one and if you'd like to help support me and this channel then checking out my gumroad store and patreon page are really great ways to help support me and the channel and then just one more thing before we start i want to thank this video's sponsor sketchfab on sketchfab you can upload your own 3d models and preview them in your browser you can even view them in ar vr or on a phone or tablet you can also purchase 3d models and assets from sketchfab's model store you can even apply to sell your own models on the platform check out sketchfab with the link in the description alright so here is the startup blender file with the basic r model so again if you'd like to follow along you can download the free project files for this tutorial with the link in the description or you can model your own character's arm if you have a character you've already created so the first thing that i'm going to do is hold down the shift and s button and i'm going to move my mouse over to cursor to world origin and then let go and that's just going to ensure that 3d cursor is in the very center there of the 3d scene and i want it in the very center there so that when i add the armature it's going to be added right there in the center so i can now press shift a and shift day will bring up the add menu and i'm going to go right down here to armature and then i'm going to select the single bone now there are a couple settings that i want to change with this bone so if you select the bone you can click right over here on the object data properties the icon is a little stick figure and i want to open up the viewport display so there's two things that i want to do the first thing that i want to do is check the in front and that way this bone is going to be in front of any of the mesh so it'll be really easy to see and then the other thing that i want to do is i want to click on the display as and i'm going to change this to b bone instead you don't have to use this if you don't want to but i prefer the b bone and why i like the b bone is because you can change the visual size of the bone alright so we just have one bone but i want to be able to edit this bone so i'm going to press tab and that will take me into edit mode of the bones you can also just click right here and change it to edit mode so i'm now going to select the top of the bone and i'm going to press 1 on the numpad to go to front view and i'm going to press g to grab and just kind of move this down and also just for demonstration purposes i am going to have kind of like a shoulder bone so i'm going to click on the back of the bone right here and press g to grab and i'm just going to like stick this over here and then i will select the front of the bone and i'll press g to grab and just stick the bone right here so wherever these circles are or wherever the end of the bone is that is where the bone is going to rotate so there is going to be a joint in between each bone so make sure you put the end of the bone wherever you want it to rotate so because this is the shoulder i'm going to put it right about there now you can see this bone is very thick so you can select the center of the bone and then you can press control alt s and ctrl alt s is going to change the visual size of the bone so it's going to change the thickness but it's not actually going to change where the bone is and that will work if you have the viewport display set to b bone all right so i now need to extrude out the other bones so i'm going to select the circle here and i'm going to press the e key and the e key is going to extrude out bones so i'm going to bring this bone right here because that is where the elbow is going to be you can also press 7 on the numpad to go to top view and you can see i need to double tap the a key to select everything and press g to grab and i'm going to hit y to bring it back on the y-axis and i'll just stick it there so i'm now going to select the circle again the end of the bone here and i'm going to press e to extrude and that is going to extrude out another bone and then i can place it right there then i'm going to press e to extrude again and this is just going to be a small bone kind of right here and then i'll press e to extrude again just stick this one kind of right there in the center and then e to extrude again we'll put this all the way down there and then i can press one on the numpad to go to front view and i'll press g to grab kind of stick this down here i can also hold down the z button and go over to wireframe and let go that'll go into wireframe and then that way i can select the joints right there and press g to grab and just kind of stick them right in there in the center and it is important that you put the bones pretty much in the center of the mesh so inside the mesh and then i'm also going to bring this down a little bit and i will select this one and bring it down a little bit now if your character has fingers that's totally fine you can just go back here and then select this circle here and you can press e to extrude and you can extrude out more bones for each finger and you could just continue to do that by like extruding out all these bones here and creating all the fingers i'm not going to do that though because my character just has like a mitten hand so i'm going to press ctrl z to undo that but it's really easy just to select the circle there and then extrude out more bones for all the fingers now i do want to extrude out a couple bones here for the thumb so i'm going to press 7 on the notepad for top view and then i can just press e to extrude we're going to extrude out a bone there just click to place that maybe about there and then e to extrude and we'll put another one there and then you can press the one on the numpad to go to the front view and i can press g to grab and you can hit z to bring it down on the z-axis and just kind of make sure it's inside there and just kind of bring this down a little bit more so something like that all right that is pretty good so now what i want to do is i want to create some controller bones for the inverse kinematics or ik so the two ik bones that i want to have is one bone over here to control where the elbow is rotating and then the other one is going to be one bone right here and the bone that's right here is going to move the entire arm and also rotate the wrist so i'm going to select this bone right here and then i want to duplicate it so i'm going to press shift d to duplicate and then i can just right click so it hops back to the very center now if i press g to grab you can see that there's that little line there and so that is telling us that the bone is parented to another bone so i'm going to right click or you can also just hit the escape key to go out of that so i want to unparent this bone so that it is separate so what i'm going to do is press alt p with that bone selected and i'm going to click on clear parent so if you press g to grab you can see there's not that checkered line there so i can just right click to bring that back to the center there so now what i want to do is i want to make this bone bigger just so that we can tell it apart so i'm going to press ctrl alt s so control alt s is going to change the visual size of the bone so i'm just going to bring that out so now it is kind of like a square all right so that is that one so i now want to make another bone for where the elbow is going to be and where the elbow is going to rotate so i'm going to select the circle right here and i'm going to press 7 on the numpad to go to the top view let's press e to extrude so e is going to extrude out bones and then i can hit y to bring it over on the y axis and i'll just place it there now if i select this bone and press g to grab you can see it's pulling on the other bones it's pulling the other bones along with it so i'm just going to select this bone and then again just like with the other ik bone i'm going to press alt p and then i want to click on it clear parent and that way i can press g to grab and then i can hit y to bring it on the y-axis and i'll just bring that out and i'm just going to bring it kind of about here and then i'm also going to press s to scale and just scale that down a little bit and then just like this bone i want to make it a bit thicker so what i'm going to do is i'm going to press ctrl alt s and ctrl alt s again will change the visual scale of the bone so now this bone is going to control the rotation of the elbow all right so i'm now going to rename all the bones so what i'm going to do is click right here to go to the bone properties so it's a little icon of a bone so i'm now just going to select each bone and i'm going to rename it so i'm just going to select this bone here i can click right here and that is going to rename it and i can just rename this to like shoulder and then i can click right here and then i can click here to rename this and i'm going to call this like upper arm you can really just rename it to whatever makes sense to you so i can click on this one and i'm going to rename this one to lower arm and then i'm going to click on this one right here this one i'm going to rename to elbow let's also click on this one here and this one i'm going to rename to wrist and then also i'm going to hold down the z button go into the wire frame so i can see these bones here so i'm gonna select this one here and then this bone right in here that's inside the other bone i'm just gonna rename that to hand and then i'll also click on this one and i can just call this like finger one and then i will click on this one and this one i'm gonna rename to like finger two and then let's click on this one right here and i'm gonna rename this to like thumb one and then one more i'll click on this one here and i can rename this to thumb two alright so we are now ready to set up the inverse kinematics so that the bones can work together because for instance when i move this one i want this one to move the rotation of the elbow and when i move this bone this big one right here i want this to be able to move the entire arm and then also rotate the wrist so i'm going to press ctrl z to undo that just bring that back there so what i'm going to do in edit mode is i'll actually click right here and i'm going to go into pose mode of the bone so we are now in pose mode so what i'm now going to do is click on this bone right here the smaller bone that's inside the bigger bone right here so just select that one and then i'm going to click right over here to the bone constraint properties so now let's add the inverse kinematics so i can click on add bone constraint and i'm going to add the inverse kinematics now this might look a little bit complex but don't worry i'll show you how to set this all up so the first thing that we want to do is set the target and the target is basically just the entire armature so you can just click right here and if you only have one armature you can just select the armature you can see right here in the outliner it's just the entire armature object so just select the armature that you are using in this case it's just this armature right here it's the only one i have so now within this armature we need to select a bone which is going to actually control the arm so i'm going to click on this bone right here and this is why it was really important that we renamed the bone so we can actually tell which bone is which so i want to select the wrist so select the wrist bone i renamed this bone to wrist so add that bone right in there now you can see that something is wrong this bone is kind of moving over and so basically what this bone is doing is it's moving over to the very starting of this bone because this bone we just selected here in this option and so what we need to do to fix this to fix this bone moving to the back of this other bone is we just need to turn off the used tail because i don't want to use the used tail so i'm going to uncheck that and then that bone is going to be brought back to its default position so if i now select this bone right here i can press g to grab and you can see it's moving the entire arm now there are a few problems one problem is that if i rotate this it's not moving the hand so we will fix that another problem is that it is moving the shoulder as well and i just want it to move the arms but not the shoulder and then also we still need to set up this bone right here so what you can do if you've moved all the bones around is you can double tap the a key to select all the bones and then to bring them back to their default position make sure you're in pose mode when you do this to bring them back to their default position you can hit alt r and that's going to clear any rotations alt g that's going to clear any locations and then alt s and that will clear any scale so just hit alt r alt g and alt s so i'm going to click back on the yellow bone because that is the one with the ik so you can see that there's that yellow line there and the yellow line is going all the way to the end of the armature and so that is showing us that this bone is going to move all of the armature but i don't want it to move the entire armature i just want it to move the arm so what we can do is we can turn up the chain length so on default the chain length is set to zero and so that's telling it just to move all the bones but if i turn the chain length up to one now it's just going to move one bone so if i select this bone and press g to grab you can see it's just moving one bone that is behind it i'm going to click back on the yellow bone and i want to set the chain length to two so now that it's set to two if i click on this bone and press g to grab you can see it's just moving the arm so that is exactly what i want so i'm just going to select this bone again and i'll press alt g to clear any movements now another thing we need to add is we need to make this bone be able to rotate the elbow so i'm going to click back over here click back on the yellow bone and to set this up we're going to add this as the pull target so first you can click on the pull target and again just like the target right up here all we want to do is we want to select this armature so just select the armature now for this one right here the pull target bone we want to click on this and we want to select the elbow so the elbow is this bone right here so if you forgot what you renamed it to just click on this you can see it's renamed to elbow so just click back over here on the yellow bone and make sure you select the elbow now when i selected that bone you can see something rotated so if i click on the x to get rid of that you can see it rotated back so i'm going to click on this and then just click on elbow again you can see it moves so why this is moving is because of this pull angle so what we need to do is just change the pull angle to rotate it back to the rotation that we want now usually you're just going to need to change this to either a value of 90 or either a value of negative 90. so you can just try that out you can change the pull angle to 90 but you can see that is now moving the elbow over so it's moving it farther away and that's because it's rotating it but instead i'm going to bring this all the way back to a negative 90. so i'm actually just going to type in negative 90 and you can see now that is rotating a bit more this way so you can just rotate that pull angle until it is moving the closest to this one so now you can see it's kind of just rotating back just slightly so it's facing this now so if i select this bone i can press g to grab and just kind of move that up and then i can select this bone and i can press r to rotate and you can see now the elbow is going to follow along with this bone and then again you can double tap the a key to select all the bones and you can press alt g to clear any location values of the bone just to bring all the bones back to the very center all right now there is another really important thing i want to be able to rotate this bone and have this bone rotate the entire wrist and rotate the entire hand so what we're going to do is we're going to add another bone constraint so click on this bone right here and if i rotate this bone you can see it's rotating the entire hand so what i'm going to do now is click on add bone constraint and i'm going to go right down here and i'm going to add a copy rotation so then scroll down here to the copy rotation and on the target i want to click on this and again i just want to select this armature so i'm going to click on armature and then on the bone here i'm going to click on this and i want to select the wrist because i want the wrist to have control so i'm going to click on the wrist and now if i click on this right here the wrist i can press g to grab and then i can press r to rotate and you can see this bone not only has control the arm but it also has control of the wrist now this entire time these bones aren't moving the mesh so it's now time to parent the mesh to the bones but before we do that there is one really important thing we don't want these two ik bones to move the mesh because these two ik bones move the other bones which in turn move the mesh so to tell these bones to not move the mesh just click on this bone and then you're going to click right over here on the bone properties and we want to turn off the d form so just uncheck the deform click on this other one as well and turn off the d form this way these bones are not going to move the mesh they're only going to move the bones but then these other bones will move the mesh all right so what i'm going to do now is click on pose mode and i'm going to go back to object mode and i can also hold down the z button and go back into the solid view so what i'll do now in object mode is just select the mesh hold down the shift key and then select the bones now to parent the bones to the mesh i'm going to press ctrl p control p is going to bring up the apparent settings and i'm going to click on automatic weights and so when you do this with the automatic weights blender is automatically going to do the best job that it can to parent the mesh to the bones so now what i can do is i can just select the bones and then i can click right here on the object mode and go to pose mode or you can also press control tab so control tab is the shortcut key to go into pose mode and i can now select the bones and you can see it's moving around the mesh now if i move these around you can see some things are not working exactly how i want like for instance when i move the arm it's also moving the shoulder and i don't really want that and so what you can do is you can actually manually edit the weight paint of each bone so you can manually edit how the bone controls the mesh so to do this i'm going to click on pose mode and i'm going to go back to object mode so i will now select the armature in object mode and then i'm going to hold down the shift key and then select the mesh then what i can do with both of these selected but with the mesh selected last is i can click on object mode and i can go to the weight paint so now what you can do is you can just use whichever mouse button you use to select and you can select different bones now i use the right click select but left click select is now the default so you're probably using the left click so just left click and select the different bones and it's actually going to show you a visual representation of how each bone is moving the mesh so if the weight pain is red that part of the mesh is fully being moved along with the bone but as the color gets more and more blue it's going to be affected less and less and then when it is the dark blue it's not going to be moved at all so for instance if i select this bone right here this bone is moving all of the red area but then it's slowly moving less and less of the mesh and then it's not moving any of the blue area so we can actually paint on the mesh to change how it's affected so for instance on this bone right here this bone kind of has a light blue right here on the shoulder and i don't want that because i don't want the shoulder to be moved along with this bone so what i can do is i can actually just click right up here click on this icon and then we have some different brushes i want to remove color so i'm going to change this to subtract and then you can also change the radius and the strength of your brush right here so i can now just click and drag and you can see that i am turning this back to a dark blue and as i turn it to a dark blue you can see it's actually going back to its original shape so now if i select the main controller bone and press g to grab you can see the shoulder isn't being moved along as much now because i weight painted that and manually changed how it's moving the mesh so you can just continue to select different bones and you can add value or you can remove value so for instance on this bone right here if i hold down the z button go over to wireframe i want to add a little bit more value to this one so what i can do is click right here on these uh so what i can do is click right here on the weight paint settings and instead of subtract i want to add value so i'm going to change this instead to add so then what i can do is i can just start to paint here and i can add more value where i want this bone to control the mesh more so now i can just rotate this and you can see it pulls along more of the mesh where that is red so you can just continue to do this by clicking on different bones and you can click right here and you can either use the add to add color or the subtract to remove color now if you select these bones right here these two ik bones they make the mesh pink and why that is is because we turned off the d form because again we don't want these bones to move the mesh we just want these bones to move the other bones but then the other bones move the mesh and then once you are done with the weight painting you can just click on weight paint and you can go back to object mode and then i'm going to hold down the z button and go back into the solid view so then i will select the armature just select the armature i'll press ctrl tab and that'll go into pose mode and then i can just select the bones and move them around and that is it so that is how you do basic arm rigging in blender and again if you'd like to learn how to model and rig a complete basic character then i have tutorials on basic character modeling and basic character rigging i'll have the links in the description and i will also be releasing a tutorial on how to do leg rigging in blender so if you'd like to check that out again link is in the description and if you'd like to help support me and this channel i will also have links in the description to my gumroad store and patreon page those are great ways to help support the channel so i hope this tutorial was helpful and thank you for watching

Channel: Ryan King Art

Views: 42,391

Keywords: Ryan King Art, Blender Tutorial, Blender, Ryan King, Tutorial, arm, rigging, IK, inverse kinematics, ik rigging, arm rigging, rigging tutorial, blender rigging

Id: Rbl080ZfAgA

Length: 20min 18sec (1218 seconds)

Published: Wed Apr 20 2022