As someone who has used sims mods that has happened many times lol. I had the extreme violence mod and my toddler got stabbed out of nowhere, and while she was being stabbed her limbs stretched out in weird ways. Pretty disturbing lol.
I think an important thing in 3D modeling is keeping the volume consistent. For instance when you bend your finger you see the first segment get wider, but your fingers overall volume stays the same.
Another point to prove that there is no difference between medieval blacksmiths and today's 3D modelers. They both also look at a thing which emits light all day.
Enable "preserve volume" on the armature modifier. There are similar options in most game engines, once you have imported it. It is great for clothing too 🙂
@@thFaust Actually dual quarternion is not part on unreal engine, at least not on UE5. I heard that there are plugins to enable dual quarternion on UE4 via plugins.
Another way around this problem is to use blend shapes, I think they're called (I'm a little rusty) - where you can define how you want the geometry to behave while in the "bent" shape. You can then map the blend shapes to animations to either supplement or replace the animation.
Yeah, "Corrective Shape Keys" in Blender. Blendshapes that activate with the bone movement. A great tool, especially for the situations where for example you want to add realistic muscle contractions and bulging. Pity it's not supported in every game engine.
@@xonxt definitely a pity… they’re often not implemented because they’re drastically more expensive to compute than a simple bone rigging. Games are obsessed with performance. Though some modern games do have blend/bulge/stretch mechanics for their meshes.
@@funknick Well performance is pretty damn important, why would devs spend time on stuff that most customers won't even experience because of high hardware demands. Personally the focus on graphics over stuff like physics or just decent gameplay is what irks me the most these days, in AAA games at least since Indie is a mixed bag of different stuff.
@@Tacticaviator7 I don’t disagree with your perspective. I also respect others who try and push boundaries. You can have both since this industry is huge and everyone can innovate the way they see fit. Nothing wrong with some folks wanting to see how well they can animate mesh content.
I think another important factor is that they make animating require more time, and so game studios and indie devs might only do it sparingly or not at all
weight painting also affects it greatly. using the auto weight paint in blender often gets you weird results where your limbs might bend and twist parts of the torso when moving them. 0:27 that vertex sticking out on the left could be fixed by giving the hand bone greater weight on it than the finger bone. anyways, great explanation
Another technique to mitigate deforming is combining with blend shapes, so as the joint moves the blend shape counters the undesired pinching or kinking, you can also make muscles flex with this
lmao once i spent all day following a ragdoll tutorial in blender, my crappy charmin bear i had modeled melted faster than the nazis in raiders of the lost ark
If you don't wanna merge verts, thus creating poles at the joints, another option is fanned loops, where there are those same 3 or 5 or 7 loop cuts around the limb, but the edges on the inside of the joint are closer together. This is a technique i actually picked up from a from a professionally made character model ripped from a game. But on the other hand, i think that the joints are one place where poles can be more of a help than a hinderance. Another thing one can do, but i haven't seen done often, especially in the game-dev world, probably more common in animation though, are double-jointed knees and elbows; basically having an extra bone at the knee or elbow and thus two points of rotation, that makes the deformation look significantly more natural, because that's kinda how knees (and elbows) work.
There's also the technique of setting up a blend shape to "fix" the geometry as it bends. You can even set up a driver between the blend shape and the angle constraint on the joint, so that it blends automatically the more the angle of rotation incresases :)
Also move the bone closer to the inner joint so the inner vertex moves less when bending while the outer joint can still get the nice smooth bend from the added outer vertex's.
by the way you can manually modify and correct the deformed shape then save the deformation data in shape keys so it looks way natural while animating.. i feel like it's better to manually edit it the way you want . you can check the pose shape keys video in blender studio rigging tools course , this part is for free and i hope it might help !
iv just accepted the way things are. I just try and make my rig as smooth as possible it never perfect. cuz in crouching poses the back of the lower knee clips into the upper knee . especially when character are wearing pants that are thicker. but oh well . luckily perfectionist are not gamers so nobody is out there judging our slightly off bending and clipping issues in more compact poses.
This was something I struggled with in college, and while I did not nourish my skills with 3D over 2D Pursuits, it came to my understanding over the years that 3D Graphics or animation have as much to do with understanding physics as it does with conveying motion like we see in the real world, minus the exaggeration.
I personally just bypass this problem by creating all the body parts I want to animate as separate objects, which results in my characters looking like puppets. A lot of really old videogame models are made this way.
Iv played with playsation 1 / 2 style models they are very fun tho I like to just stick to adding way 5 to 7 vertex lines in every bendable area it gives it a smooth look I rig it in a way to avoid getting the holes and pinching happen. but in return deoe ding on the pose the lower leg and upper leg can clip into each other tho . I don't animate many scenes with sitting on your legs or crouching down so usually it dosent happen .
yup not relevant here that is more for clipping problems if anything the elbow joint is being covered by the elbow armor joint so you would not even care if there was any odd deforming happen under it
I love your videos man. I love the freshness, the freedom you give yourself when it comes to the topics. This one in particular really made me think of rig geometry in a way I hadn't yet. I'm not a 3d modeler but I'm getting into software for 2d animation that deals with meshes and rigs, and this video made me realize some stuff. Thank you.
thank you for making this video i knew about adding loop cuts but i didn't know about the merging of the vertices thing i guess it's more things to keep in mind for my next project
I recently stumbled onto the channel Bracer Jack, he has a really good video on low poly hand modeling where he gets into modeling with animation in mind to minimize unwanted deformation
I want to say; I love watching you videos Garbaj because I am a game developer my self and your videos help out a lot on giving different perspectives on solving certain problems in video games. It is such a pain in the butt making 3d models for a game because of animation and getting it to looking right.These types of videos are just so helpful. Thank you
There are a couple of papers describing algorithms to improve this. It would probably be worth a try to implement one of them. The one I found recently by Disney describes one that runs in real-time.
Dual Quaternion Skinning the one you might be thinking of/referring to. Blender has an option for this called "volume preservation" It has issues of its own but none that are as difficult to correct for as what we have now. Would be very interesting to see the effects of this on workflow if implemented
@@VertebreakHER its called bend shapes they been around for like 20 years you place a volume inside of the mesh and the mesh will deform around it and the blend shape will also deform how you want it with a slider example having a character flex and showing veins and muscle definition with multiple blend shapes, you can also have them linked with shaders to have more veins show by using sub surface scattering and per painted veins under on a different diffuse map.
This is why topology is super important. Placement of joints on the bones can affect the results. Alos, weight painting can be tweaked a bit. Plus, adding twist bones, deformation compensation bones, and/or even maybe blend shapes that are applied based on rotation of bones. So many methods to use, you can get pretty creative. It also depends on what is worth it. What is the range of movement the character is expected to make? What is easily visible? What is the cost (time needed, performance hit, etc)? Everything is a balancing act. In the end, the effort always shows
There's a better method for this using a circular technique for geometry around the elbow or knee or pretty much any joint, this would allow you have to have a loop only around the joints and you can add more loops around that area without it disrupting the rest of your topology
The way i got around this was by making a little cover section between the joint and then butting the joint back together so you dont see it. If youve ever seen an articulated bus, same kind of principle.
most modern game engines support shape keys, so that this is doable, but may require extra setup (unless you animate the shape keys in blender aswell and export that data)
You have to be very strategic about your bracing in a low poly situation. Something I actually noticed now that I've had some experience with it is that in Ocarina of Time, the Gerudos most likely have those poofy pants to disguise the contorsion that the knee joints get when they bend, letting the model save a few verts per leg without looking weird. Studying some games from the era can teach you a lot though, because those principles actually scale up quite well when designing a model to be rigged
@@bmomosaik some games and animations have something called retro art styles, just like pixel art is still a thing, low polygon modelling is still a thing and with less then 400/300 faces per charter model you trade the modern convince of high poly for low poly witch gives you style points and more creativity as your working in constraints and you have to think harder and its like a fun puzzle.
Interesting vide, but I feel like you got the reasoning behind medieval armor a bit wrong. Those extra plates are there because in order for the wearer to be able to use his elbows his arm and forearm armor needs to end a bit before the elbow as steel doesn't exactly bend easily. That however would leave the users elbow exposed and be a weakpoint even if covered by chain mail. Therefore additional plates of steel that covered the elbow but interefered as little as possible with the movement were installed.
For knees and elbows, I think having 2 joints each is best, that way you can manipulate the bend to avoid creases on the shared verts. Another thing I wish riggers would do is add bones for muscles, like an extra bone halfway, then that could be 'flexed'. There is a lot of shortfall with rigging, we should be adding more bones and being more exact, not just adding more vertices all the time so the horrible bend gets a little less horrible.
@@doomtownhun Well these are very low poly models, not really a true reflection of model complexity in higher detail games. For example, it's quite easy to squish a polygon, but difficult to squish a high poly knee without things going ugly... more bones = more control is all.
What about the one where the dead enemy/character mesh gets super-spidery, stretchy-deformed and flies wildly about the map (usually in and out of other meshes, like the ground)? One great example of this is Fallout New Vegas…
A rigging expert going by the handle "Adeptus Steve" had most of a whole channel dedicated to these problems and covered the workflow retargeting to Unreal's engine. Including these elbow locators or something that scaled **way outwards** when they were IK'd... ( watch?v=eIOshqZ1lkU ) ...probably overkill for an FPS game though.
just use blend shapes... been around for like 20 years vertex painting the weight can help by you should be doing that anyways... and all joints should be Ik'd no reason no to have ik handles on everything and have a menu with min and max controls with sliders. and having linked ik's to have things like a hand grab something by moving a single slider and not having to move each joint for each finger
Remember that you can use blend shapes to maintain volume as well. You can also rig another bone in there too with a constraint on it to make it scale and shrink depending on the angle and rotation of the bones around it preserving volume through the rig itself instead of mesh based things like the blendshapes.
If we are talking about deformation in general 3 edgeloops are the way to go for joints, if you merge them on one side, and you overextend that side it will still look bad, the reason why we merge them on one side is simply to save polygons, not because it's better.
1:30 thats literally how the skin is folded on our fingers! If you look at your thumb for example, at the outer side there are more wrinkles on the bending joint while on the inside there is one or two small dent-like wrinkle lines.
I liked the reference to the Chain Mail. Usually when trying to build something in the digital world its often a good idea to look for examples in the physical
I remember some paper on some algorythm that could make realistically deforming fingers etc. idk what happened to it tho probably part of some proprietary tech now
Can confirm clothes rigging in particular can be a nightmare because of this bending, it's also worth pointing out it's not just the polygon count that can cause unnatural shrinking and expanding weight painting across the same parts of the mesh can cause issues as well so if both your bones are red on one part of the mesh that will cause weirdness. You've just got to experiment and find what works for that particular model.
it's especially troublesome on clothing that has unnaturally boxy projections, like light form fitting armor plates or magazine pouches around torsos, most games now do these as seperate physics objects, especially with magazine pouches, but i still see rigging issues even in recent with sci-fi light armor panelling on torsos the moment there's any kind of bend or twist in the spine. could be solvable through blend shapes, but the curl and flexion of the torso means you would be stretching other triangles around the plates too much. the solution that ive rarely even seen any game do i think would be to have them as seperate objects not as projections of the main mesh, with blend shapes to keep the undersuit from clipping too much, but that's a ton of work and i've only ever seen it done afaik on a few characters with armor plates in ff7 remake, and some recent assassins creed games characters.
i was literally telling a friend about this yesterday when he was having issues with something he was working on. gonna have to save this one for the future to save me time when explaining it to people
Long time lurker, first time commenter. Love your style of videos, you explain stuff so simply and your voice is really chill. Best of luck with your game and streams :)
As you've shown. It's all a matter of topology. There is no getting around adding the extra vertices and faces necessary to make a movement without the entire thing turning into Gumbi.
I can’t wait for developers to eventually model joints after the real muscles and joint structures in our actual bodies. I know it will take a lot of power to computer hundreds/thousands of muscles on a character at the same time. Then to have multiple characters with the same articulation capabilities. Then to have realistic characters like that and an action scene or whatnot… lots of computing power needed, but eventually it will be awesome to see! Like when they eventually model actual entire engines and drivetrains for cars in driving simulators. Eventually, it will be awesome to see the physics interacting exactly as they do in the real world.
2 straws connected together will form a sharp angle when bent 3 straws connected together will give more room to curve it's simple if we exclude weightpaint
If I'm being brutally honest, this is why you find better topology like you were showing, but also put in another bone between each joint and socket. This works really well for knees, hips/butt, elbows, and even shoulders. I would also add in using shape keys that control the topology's quantity and quality while bending. After all, our skin stretches. Not our bones.
Good topology and corrective shape keys keep this from happening. It's not really that big of a problem, just continue working on it, if you're having issues with stuff like this then your rig probably isn't done anyway, it's less of a problem and more of something you have to prepare for beforehand / tidy up afterwards.
A really obvious but extreamly helpful technique. I don't rig or animate, so that part doesn't apply to me, but I'll keep this in mind next time I'm modeling things like street lights!
You can also use shape keys which basically vertex that have multiple location at the same time. Then use driver keys to link shape keys value with the bone
The problem is that you put teeeny tiny sticks for wire framing and the model bends around that. A real finger is like 60% bone 40% everything else, but a wire frame turns the "bone" into like
