#CGTip | How Do I Build a Quadruped Rig?

hello and welcome to another CG tip I've been doing a lot of research lately into quadruped at limbs mainly because I'm working on a full canine rig as part of my rigging in my series there are a handful of different approaches to this type of rig so I thought I'd share a few with you while also discussing the pros and cons of each plus I'll show which is my personal favorite and the one I will be using as a base for my course hopefully demonstrating how to build each will also help you when you are choosing the right approach for your own rigs as another bonus I also spent some time updating my auto limb rigging tool with some cool new features I'm also going to make the final Maya file used in this video available so you can download it and play around with each limp configuration okay so here we have the Maya scene which I'll be working through and the eagle-eyed among you will notice I already have a series of layers and groups set up this is just to speed things up for the video and keep each rig separate so here we have the first limb it's already skinned and ready to be ripped there are also a couple of basic control icons here too for us to use the very first rig we are going to build is probably the simplest to start we need an eye care handle so go to skeleton create I care handle and open the options we just need to change this to rotate play in solver which will also give us the option of using a pole vector later so we can control the knees position select the hip joint R in this case the femur and then the ankle R as this joint is called the metacarpus this will create the I care handle let's rename that to ankle underscore I care handle and all we need to do is parent it to the main power control so it will move along with it we don't want the animator moving the I care handle directly as you can see we can now move the power control and the leg bends as we would expect he actually works quite well for such a basic setup we just need to stabilize the power to do this we just use another I care handle but this time a single chain solver will do because we don't need that additional rotation control we just create that from the ankle to the end of the toe and let's rename this one to toe I care handle just like the ankle I care handle this must be parented to the park control to so now as we move the control around the knees Bend and the poor is stable we can use the tour I care handle to manipulate the pot so this could ultimately be connected to another control if needed or some attributes we also have this knee control so let's wire that up next all we need to do is select the ankle like it handle and go to constrain pole vector we can now use this to control whether knee points so that's a nice and easy quadrupeds rig we get some nice information and the animator could use this to create a walk or run cycle okay let's bring up option two this rig is very similar to the first except we are going to use a different eye care handle let's open the eye care handle options again to begin with let's add in the tour I K just the same as we did before using a single chain solver and rename that and parent it to the poor control okay that's in so let's add the second I care handle as you can see here we only have two options and by default this is all you will get what we need to do is activate another option a mayor is quite sneaky with this because it's almost hidden go down to the Mel input here and type I case bring solver make sure it's all one word on the two S's are capitals now you'll see we have two more options the human eye case over and the IKE a spring solver select the spring solver create one from the femur to the metacarpus just as you did with the first rig rename this to ankle I care handle too and parent it to the par control it's all so quickly use a pole vector constraint to add in the knee control there we go if we select both neat controls now and move them you will see that the movement looks almost identical in fact I think is let's move both of the power controls now to see how these differ I'll just close this you so as you can see we now have a difference in how these limbs are bending the distance here on the rotate plain limb is different to the spring eyecare limb that's because the spring I case Oliver tries to keep the bending angles more evenly spaced so this results in a nicer deforming limb now you can adjust the spring solver in the attributes if I select the I care handle and go down to I case her attributes and then I guess bring solver attributes you can see that we can adjust the spring angle bias ramp now there is a way of adding this functionality into your rig but to be honest I think it's more work than it's actually worth doing with regards to the functionality you will ultimately get but that said though the spring IQ solver rig is definitely far superior to the real tape playing solver rig okay let's reset these the first two and they are quite easy to set up so onto number three unless start with that till I handle just the same as we did before using a single chain solver we are going back to the royalty at playing solver this time but create one from the femur to the metatarsus instead so we aren't affecting the whole leg with this one let's rename these before we get too far ahead so - I care handle Annie I can handle now we are going to use a second single chain solver but this will go from the metatarsus down to the metacarpus sorry if these names start to get confusing but you can see which ones I'm selecting if you're not sure so this time we are dividing the ik2 to let's call this hop I care handle I will pair those three to the park control you so we can move all of those around and the light moves with them the problem is the hawk is now static I'll just add in the pole vector constraint so we can add the knee movement into the rig that's good the problem here is we have no control over the lower portion of the limb but we can easily add that in with the knee I care handle selected simply group it by pressing ctrl + G let's rename the group to me I care handle offset I now need to move the pivot point so to do that we just press insert see the pivot is all the way back here if I hold V I can try and snap the pivot to the lower joint here looks like it's snapping to the vertices I'll hide the polygons temporarily there we go just bring those back we can now use that group to control the lower leg like this you see we just use the rotations so you could easily add these to a control to make it more interactive or just add some extra attributes to the power control so the beauty of this setup is that we have more control over the overall pose of the leg the problem is it means a bit of extra work for the animator so it's a trade-off really you you see even with the spring base rig you'd have to go in and adjust the spring bias ramp which isn't ideal but you wouldn't be able to get this sort of pose with the first two rigs so out of these three the first two are good for general animation but the third is better for achieving more poses okay on to number four here we go and you will notice this has two knee controls instead of one okay let's quickly add the two I care handling and rename it and also parent it to the power control we now need a rotate plane solver and we are going to start the same way as we did previously so going from the femur to the metatarsus call this one knee I care handle now create another going from the fibula down to the metacarpus so you see these two are overlapping call this Hawk I care handle parent these two the part two so you see this is why we need two knee controls so let's use pole vector constraints on these we will constrain this one to the front control on this to the back so again we can control the like but we do still have the static hot section here we can however use the knee control to adjust the front and back knees you you could also add a control to the knee I care handle so you can move that around to get a little more control out of the hock so this essentially has three controls so it's more for the animator to play with which could complicate things Plus even with the extra ability to move the IKEA handle at the back of the leg the poses you can achieve are still limited you do get some nice movement with the front knee control as you can see it travels all the way down the leg that's four legs let's move on to number five you'll see with this one that we've dropped back down to just the one need control this is also the first setup where we are going to use two skeletons so let's duplicate the route control this up I'm also going to add a prefix to these joints so we can clearly see the difference between the two joint chains I'll call it driver because this skeleton is going to drive a second just remove that one as well okay you so we're going to use a spring solver this time and this is going to cover the whole like just like the second dog like rig but it's important that this only affects the driver skeleton we can add an eye care handle in the outliner rather than the viewport select the femur first and then holding ctrl select the metacarpus this gives us that nice global control which means all three joints are moving I'll just hide the driver now because we need to work on the main watt which is connected to the skin now we need a rotate playing solver this will go from the femur to the metatarsus joint actually let's rename these uncle I care handle you and driver take a handle and move those so they are parented to the park control we now need a single chain solver I care handle and this will go from the metatarsus to the metacarpus so we're essentially copying the third rig rebuilt call this Hawk I care handle and parent that to the power control to so then we have the same setup as the earlier rig with the hawk remaining static what we're going to do instead is make the I care handles follow the driver skeleton so we should get a much better movement through all three joints so parent the ankle I care handle to the I'll just make the driver skeleton visible again so we can see okay so apparently ankle I care handled to the driver metatarsus joint and the hawk I care handle shall be parented to the metacarpus joint what we can also do is add in the same functionality we used earlier - so let's add a group to the ankle I care handled I'll move the pivot down to the metacarpus joint you okay that works just rename the group you and I'll hide the driver skeleton too oh I'll just fix that power movement so just use another single chain solver you parented to the poor okay much better so you can see now as we move the power controls we are getting full movement throughout the leg the hawk isn't static as it was with version 3 plus we still have the offset group meaning we can pose the lower leg to when needed with this rig we essentially combined versions two and three so we get the best of both worlds it works like this because handles are following the joint positions of the driver skeleton which is being controlled with the spring I K if we go back and compare with version 3 you you can see that we have more natural movement and the hawk isn't static but we also still have that extra level of control I'll just reset these there's one more step we need to follow with this lip if we move it from the opposite end you will see that the hock is static again so we've lost that natural movement this is only happening because the root of the driver skeleton isn't following so we need to adjust the hierarchy all we need to do is move the driver femur so it's parented to the root joint now if we move the root joint that movement has returned you can hide the dry now too there we go okay on to version six and this is the last one I wanted to share with you today again you can see this has two knee controls so just like the last leg rig we need two skeletons again duplicate the route joint and let's add another prefix for clarity let's call this one driver again and remove that one we're going to use a spring solver on the driver skeleton just the same as before so create it from the femur to the metacarpus joint I'll rename it to driver I care handle and also apparent it to the poor control I'll hide the driver skeleton create a rotate plane solver going from the fibula to the metacarpus joints and collect hawk I care handle move it under the park control to now parent the hawk I care handle to the driver I can't handle although thinking about it you can probably skip that if they are both parented to the control anyway it will just do the same thing now parent the femur to the driver femur we need that to follow the driver joint okay I keep forgetting to add the two I care handle you I'll hide the driver skeleton you okay that's better now let's connect the knee controls we're just going to use two pole vector constraints you there we go so this is similar to version 4 with the Tuni controls but we get the added flexibility of the extra joint chain okay so that's the six main rigs I wanted to share with you today what I'm gonna do now is I'm just going to spend a little bit of time cleaning them up and adding in a few extra controls but I'll be back in a sec so I've gone through the rigs now and tidy them up I also added some extra controls here for those groups we added these are more interactive than just using attributes to drive things let's move all the legs now and see what we have you we can clearly see the differences between some of these rigs especially the ones with the separate hot controls with the first tube which are just simple I care handle rigs we can control the knees but that's about all number three we can control the knee but we have full control over the hock so we can achieve more poses with this one if we look at number four we have the Tunis controls but movement is slightly limited compared to number three although I think I forgot to add in the extra control for the IKEA handle I'll make sure that's updated in the source files so you can play around with it so I've just gone in and quickly added in the extra control and this is just something along the lines of what I was thinking but again you'll be able to play around with this in the source files for me though it's still too many controls to give the animator with number five we have the same setup as number three but we have the added flexibility of the spring solver giving the leg more movement number six suffers from the same limitations is number four with the two knee controls but not much of an option for controlling the angle of the hock let's try the movement from the upper leg instead you we have the obvious issues with the hoc areas on these to wear those would need to be animated separately but the others Bend quite nicely I do like that added functionality that comes with number three and number five yeah I think after testing all these rigs that number five is that one I would recommend using it moves well initially but you also get that extra level of control with the hawk so the animator could create a walk or run cycle but then they can also pose a limp - I feel like the others are just too limited now this isn't the end of story because we have another area to think about and that's the front leg yes you may think that the front and back leg should be the same but they're not if we look at this model and skeleton you can see that the anatomy is clearly different the skeleton has more of a forwards curve to it plus the lower Karpis joint here needs to bend backwards so if I had a spring solver I care handle as we did with the other limbs a movie you the light bends the wrong way so this would look wrong because this section needs to go this way you in this instance simpler setup like we saw with rig number three could be the better option because it would give the hock flexibility and freedom it needs okay so I think that's all the quadrupedal in rigs covered well the main ones anyway I spent a lot of time playing with different configurations but these were the more popular and more stable options if you do have another approach however or a better configuration I'd love to see it so please let me know and also remember that antsy GI Club members could go ahead and download this file now so you can play around an experiment with these limbs yourself okay so it's time to talk about the updates I did to the auto limb rigging tool the ones that I mentioned at the beginning of the video as you can probably guess as well as biped support it now includes quadrupeds support too so you can automatically generate a dogleg for your rigs let's have a look at it in action so you can get a better idea of how it works so here we have four quadrupedal limbs two at the back and two at the front if I open the tool which is now a version 2 you will see it's looking a little different to version 1 there's a news section up here which will tell you what's been updated and what future updates are planned the loom type drop-down box has been updated with the new quad rependa options you will see that there are some options that are grayed out that's because these haven't been added yet but will be in future releases just like down here the disabled options aren't yet available but they give you an idea of what's coming now how soon these happen is really up to you guys the master part as I get either here on youtube or over on my patreon page the more time I can spend developing this and all the other tools I have planned I'd also love to hear any ideas you have of what you would like to see adding to this tool I want to make this as useful as possible for you okay so just as before we need to make sure the orientations are set up to match the limb primary axis is the joint which points down the joint so in this case it's why the secondary axis is Z as that's pointing forward although with this joint it's looking like it's pointing more up and the up axis is X which again with this joint makes things even more confusing as this is pointing right so long as the primary axis is set you can adjust the other two to get the right setup for your particular limp these options are mainly for helping to position controls although thinking about it I will look into simplifying this in future updates I think these axes do make more sense if you're working on a biped arm so what we do is select the like joints we need to change the limb type to quadruped adrià because this is the back leg and we are working on the left side so it's the same as you'd work when using version one there are options down here for selecting if you want stretchy limbs volume preservation and if you want to use a spring IQ solver but we'll talk more about those shortly what we do then is click go and the limb is rigged we also have a nice little power icon too so we can move the whole leg around there's the hot control - for that extra level of flexibility you will notice that these extra icons have appeared too and this is another upgrade from version 1 I decided to add these in for you to save you even more time there's a global route control and on this is included lots of attributes food to use these are for controlling the rig visibility and what the animator has access to I also added a full hierarchy to again to keep things organized the only elements I didn't organized was the base skeletons you will need to move these into the export skeleton group manually just for now so we had stretch enabled here so if we move the leg you see it stretches the spring solver option used on the Quadra pet limbs and you will see I added this in and didn't just force you to always use this solver if I stretch the leg once I go past a certain point the joint start to drift away from the control now this is an issue with the spring solver so yes using the solver will give us a nicer shape when the light falls together but if we want a stretchy limb it's not as useful let's just undo this and go back to the beginning if I disable spring solver this time and rebuild the light looks exactly the same but this time it's using a rotate plane solver so as you can see here it's not folding as nicely but as it stretches the joint stay locked to the park control so its trade off really I'd say if the stretchy limb is important to the rig then just disable the springs over okay let's rig the right leg so we do is select the joints set this to right and click go and there we go the other leg is rigged so in addition to the stretch option we also have the volume option and what this does is add volume preservation into the rig what this will do is as the leg stretches it will update the leg to maintain its volume so essentially the leg will get thinner the more it stretches now it's difficult to see here because these joints aren't skinned if I select them in like control you will see we have a volume offset attribute this will allow you to also adjust the thickness if I adjust this now you will see the joint scaling so the animator can use this to make the limbs bulge and shrink to that's the rear legs let's look at the front legs and as I mentioned earlier in the video the rig for the front legs needs to be tackled in a slightly different way so start by selecting the joints change limb type to quadrupeds front and side to life click go so there we go nice and easy not rigged and we can move it around you will notice that the hoc section is more rigid this is because this area on a front quadrupedal M needs to bend a different way so we can't use the same rig as the back like it's a simpler rig but it will give you more accurate control let's rig the right light now you so there we have all the legs rigged in a matter of seconds they all also have stretchy limbs with volume preservation and full eye care and FK support all I need to do now is move these joints into the hierarchy you there we go you they all move now with the route control to okay let's hide those for now and bring in some basic biped joints so this is what version 1 was able to do but even this part has had some improvements let's quickly rig the arm okay that's rigged but because I hit the hierarchy we can't see the controls I'll just make that visible again there we go the left arm is rigged and the right arm you will notice at the left right controls are different colors now too which is a small upgrade from version one of the tool we don't just need to control the limbs from the ends we can also move the route controls to its these controls which you would pair into any hip clavicle or shoulder controls so they move with the torso now let's rig the biped legs remember to update the drop-down boxes I added a foot icon - in this version so it just makes things easier for the animator and let's do the right leg you so that's the legs done another update I added was to orient the foot controls so they match the worlds orientation again this just makes animation so much easier I'll just move these joints into the export skeleton group so there we go with this tool have managed to rig eight limbs in a matter of minutes and they could all be part of the same character too you now this tool is still in development and as you can see here so much more I want to add into it for you but I can only do this with your support so please consider joining the at CGI Club so I can create more tools and videos for you in the future speaking of which those of you who are already part of the club can go ahead and download this script and the Maya Singh file now well we've come to the end of another video if you found it useful please hit that like button to show your support by your attic you could also subscribe and enable notifications so you are kept up to date with future videos and community posts if you have any questions or suggestions please post them in the comments below or contact me through the uncie gie club twitter account and i will try my best to reply alternatively you could post them in the antsy GI Club discord server where I spend more of my time you can find an exclusive invitation to join in the description below remember that you can also join the antsy GI Club to help keep future videos free while also getting access to exclusive rewards like scripts models and rigs alternatively if you just like to show your appreciation why not treat me to a coffee at my coffee page the link is on the screen now and in the description below thanks again this is antsy GI signing off and I will see you on the next one you

Channel: antCGi

Views: 15,657

Keywords: rigging, maya, autodesk, maya3d, rigging in maya, rig, 2019, maya 2019, gamedev, game art, game development, game rig, game rigging, how do I, maya 2020, cgtip, quadruped, dog, dog leg, spring solver, ik solver, paw, three joint leg

Id: g-uXLNz7-70

Length: 40min 4sec (2404 seconds)

Published: Fri Jul 24 2020