3ds Max Mechanical Rigging - Part 1: HI IK Solver

okay welcome to the first video and a three-part series on mechanical rigging in 3dsmax now we're going to focus today on the H I I case solver and part 2 is going to focus on the HDI K solver and then part 3 is going to focus on how do we get argument based controllers to drive these AI case solutions so today's focus this video is going to be covering the H I I case solver and we're gonna use this aircraft model to demonstrate this I've hidden most of the aircraft except for this left main landing gear strut here and the left main landing gear strut it consists of several moving parts there's actually things here that are additional moving parts that are hidden but this is enough to show what we need to for today so we've got basically a landing gear mount block with a hinge this landing gear mount block is connected to the movement up and down movement block or assembly so this is going to be like weight on and off the wheels controlled by the shock absorber etc normally the landing gear is going to be in a position like this and then rotating into the fuselage is going to be controlled by this block here this is going to rotate up into the fuselage now as this does that as the landing gear strut rotates into the fuselage the push rod the upper push rod is going to push on the bell crank which in turn is going to pull on a lower push rod and that's going to rotate this wheel assembly into a position that allows it to fit in the fuselage now in order to control that we're going to use some bone structures and I case solvers were to use the h-i solver for this upper portion of the assembly the pushrod the bell crank and then we're gonna use an HDI K solver for this lower push rod and the wheel assembly now one thing I've done here to make it a little bit easier to work is I've rotated the landing gear into the XY plane so that I can create the bones easily and then line them up and and whatnot one of the interesting uses of the or constraints of the hii K solver is that all of its movement needs to be in a single plane so that means all of your joint positions need to be coplanar we've got three joint positions we need to control here we've got a hinge joint for the bell crank we've got a ball socket joint for the lower end of the push rod and a ball socket joint for the upper end of the push rod now those three joints are coplanar but they are not in the plane that we need them to be in so looking at towards the back of the aircraft we can see that this bellcrank needs to rotate in the XY plane about the z axis and what we want is everything to be coplanar so that means all of these joints need to be coplanar as well this is not coplanar with all of the the movement that we need so we're gonna cheat a little bit and we're going to create our bone structure in a single plane here but rather than having the Terminator bone connected up here with this socket position we're going to leave it in plane with the rest and we're just going to link that push rod to the bone now we can get away with that because the rotation axis here and here our parallel and consistent with this ball joint here so once once these two things are parallel and this is fixed in relationship to this hinge point we can then keep the bone structures parallel in this position and allow them to control the pushrod in that position without causing any distortion because of the geometry of that all right so we're going to start out we'll go to our top view and we're gonna create some bones here sorry about that go to animation bone tools and create bones now one of the first decisions you have to make is where do you want your root and where do you want your Terminator bone what you normally use as a rule of thumb for deciding that is the location that has the most movement is the one that you're going to use as the Terminator bone so it's going to have the most degrees of rotation the most position movement etc depending on how you view things if we select this sorry about that let's get out of bone creation mode here if we rotate this strut around this pin we can we can view this as either this position moving for these two joints or we could view it as this position moving in space and that gives us a little bit of freedom in how we do this but one other thing to think about is that I found that you get the most control in the rotation that you want to do by assigning the route where you want to control the rotation so for us we're going to pick this joint because we want to control the rotation of this axis of this Bell crank we're going to pick this as the root so we're going to position over here left click and drag left click and drag and left click and drag and right click to terminate now we don't have to be real accurate here because we're going to clean this up in just a moment so we just want to get it in an approximate location now if we look at our bone structure it's actually not created where we need it so we're going to have to line things up so we're going to do some selection and we're going to align with our hinge pin and we're going to pick the XYZ position and we can see that it dragged the entire bone structure down with it when we did that now to line up the rest of this we're going to go into bone edit mode and this allows us to change the length and positions of the bones without affecting the others which is a good thing because we don't want our root bone to move now that we have it in position so we select our second bone and we're going to align it and you can see that I've created a point here for my socket this is going to control the joint location it's always a good idea to create some dummies to help you do that so I just aligned it XYZ with that joint and then we're going to do the same thing with our Terminator bone with a slight bit of difference the Terminator bone is going to be aligned with the socket position like we did before but instead of align it in the Z position we're just going to leave it in the same XY plane that it was in so now we have our bone joints aligned in vertical space so X Y Z X Y Z X Y and we're just leaving the Z off because this line from this joint to this joint or this bone joint to that socket joint the line there forms an axis which is parallel to this axis which is parallel to that axis and that's going to allow us to do the right rotations that we need to do here ok so we've got our bones in position here what we're going to do now is get out of bone edit mode and we're going to create our eye case solvers so we go to animation like a solvers h.i solver OOP let's start out here let's select the root bone first there we go animation I K solvers H AI solver and then we'll drag this over and left-click on the Terminator bone now that's created our end goal the end goal is what is used to move the bone joints around the bone structure around and the the system will solve for joints in between the Terminator bone and joint and the route bone joint do all that positioning for us now if we were to drag this now we can see that we're dragging and sometimes it doesn't move or when it does it's a little jerky so the way we get rid of that is to go over here to thresholds and set this to 0 and now when we drag our end goal around the movement is nice and smooth and that's exactly what we want alright so let's go ahead and start linking parts up we're going to select our route bone and link it to our main landing gear structure we could have linked it to the hinge pin which is where we're trying to control movement either way this is going to work now we're going to link our Bell crank to our first bone we're going to take the push rod and link it to the second bone and now we can test our bone movement out so let's get up here and it will select this go into rotation and start dragging it around and we can see that our Bell crank is rotating along with the bones and it is looking just fine now let's go ahead and see if it rotated in the right plane looks pretty good if we hadn't if we hadn't have kept this bone in line with the XY plane and moved it up to the ball socket our plane would have been at a slope and then as this joint which was up here before as it and in that position as we pushed it around that plane would continue to be at that location and would have pushed the ball joint down here and that would have caused twisting in the parts so that's why we needed to have these bones lined up in the XY plane to keep this rotation in that same plane of mode motion all right this is the that's it for the first video on how to do I case solutions for rigging in mechanical parts and the second part will cover HD high K solutions to drive this push rod and this wheel assembly here thank you for watching

Channel: Jim Knutson

Views: 13,047

Keywords: Autodesk 3ds Max (Software), Tutorial (Industry)

Id: MvJ06-H2gVk

Length: 13min 15sec (795 seconds)

Published: Tue Jan 28 2014