Transforming Robot Production Pipeline Volume 6: Rigging

In this lesson, we'll begin working on our robot's foot roll rig. So thinking about the feet, they're going to be quite limited because of the robot's design. We won't have as much rotation as we would, let's say, a human's foot roll. However, we still want to provide enough control to create appealing silhouettes. So let's keep that in mind when we start to set up the animation controls for this. But to get started, what we'll do is first create the joint chain we'd need for our reverse foot. I'm going to grab one of the toe roots, duplicate it, and go ahead and move it over. Let's also make sure that our Move tool is set to Object Mode. It'll help us to move these joints around a little bit easier in place. So with the root selected, I'll go ahead and press Shift-B to unparent it. And we'll also unparent the last two joints. There we go. We're going to want these centered between our toe chains. So I'll go ahead and show you a script we can use to have that happen a little bit faster. But before that, let's go ahead and align this root joint that we've just duplicated to the ankle. So I'll go ahead and first unparent it. Actually, it should already be. So that's fine. Let's go to Wireframe mode. And we'll just go ahead and vert snap it to the joint it needs to be aligned to. If you find that it's not snapping in place, simply make sure that you don't have any of the axes already selected under move tool. If you do, just simply click in the center. And now we can go ahead and snap that joint in place. All right. So the root's taken care of. Let's go ahead and worry about the others. So again, we can use a point constraint to center these objects and then remove the point constraint once it's done its job. So that's what our script is going to do. Let's go ahead and get over to our script editor and load it in. We'll find our scripts folder, and we'll grab the Sensor Object tool. All right, so at this point we can go ahead and take a look at the code. So, pretty basic. It creates a point constraint. Then we create a variable to find our last selection, what the point constraint is added to. And then we use the List Relatives command stored in this variable. And we find the point constraint of our last selection. The last thing this code will do is delete the point constraint. So it selects it and deletes it. If we wanted to condense this a little more, we could always use the Delete command, replace that with Select and get rid of Do Delete. So we have a number of ways of taking care of the same task. But I'll now go ahead and highlight the code and go ahead and add that to the shelf. Heading over to our Shelf Editor, we can go ahead and rename it. So the tool we'll rename to Center Object Tool. We can use that for our tooltip. And to get a little bit more descriptive, we first select the target. Then we can put an open and close parentheses and an s within. Just so it's clear that we can select multiple targets. And then we select the source, what to align. All right. So our icon label, we'll go ahead and rename that to COBJ. And choose Save All Shelves. All right, let's go ahead and put this in action. So we want to center this center joint between the toe B chains. Let's go ahead and grab the two chains that surround it, followed by the joint in the center, and use our Center Object tool. OK, great. So we've taken care of that for the two end joints. So now it's just a matter of reorienting these. We also need a joint for the heel. So we'll take care of that. But first let's go ahead and reorient them. So I'll go to grab the joint in the center. Grab the joint at the ankle. And go ahead and reset their orientation just so that they are reorientated properly when we use our Reorient Joint tool. So making sure they're selected in the right order-- again, the mid joint first followed by the joint at the ankle. We can now choose Apply to reorient the joint at the ankle. For the joint in the center, we first want to grab the joint at the toe and then the center joint. And then choose Apply. And now for this last joint, we could always parent it to the joint in the center and run RJT. Now, keep in mind that the hierarchy is going to change because we're creating a reverse foot system for our foot roll. And again, we do need a joint for our heel. So let's go ahead and take care of that. What I'll do is go ahead and unparent this end joint. I'll go ahead and duplicate it and move that away in the x-axis and move it up in the y-axis, just to make sure it's on the same plane, so it's pointed straight forward. We could always use our Orthographic View to help us accomplish this. OK. So I'd say that's pretty good. So now this point, we can go ahead and grab the joint at the end, the toe joint. Let's go ahead and run the RJT tool. We'll grab the joint that we duplicated, grab our toe joint, and now go ahead and apply the Reorient Joint tool. OK. Great. So at this point, we no longer need the joint we've duplicated. We can go ahead and remove that. I'll go ahead and duplicate the toe joint. Let's go ahead and move this back to the heel. We'll also now want to move this down so that it is right at the floor. That way, when we rotate the robot's heel up, it doesn't penetrate through the floor. And it also avoids us having a gap between the feet and the floor plane. So we'll need to do the same thing for our toe. Let's go ahead and just translate it down in the y-axis. All right. That's going to work out well. Just going to work on parenting these. So we know that a toe joint gets parented to our heel. The joint in the center, which will rotate the ball of the foot, that gets parented to the toe. And the joint at the ankle will get parented to the ball joint. So at this point, we can go ahead and rename these objects. We could always use our Renaming tool. So let's go ahead and select these in order. I'll grab the ankle, grab the ball, the toe, and the heel, and use the Renamer tool. So we'll rename the ankle to J and T. Or excuse me, since this is a reverse lock chain, we'll go ahead and use the prefix RL, just to make that more descriptive, so we know exactly what this chain is for. All right. So that's RL, reverse lock. L followed by Ankle. 01. I'll go ahead and copy the name here. Go to the next joint. This was for the ball of the foot. So we'll go ahead and rename that to Ball 01. The next joint will be the toe. And then finally, the heel. So we have our reverse chain built. We can go ahead and mirror this across now. Feel free to add the Mirror Joint tool to your shelf. All righty. So everything's in place. All right. So in the next lesson, we're ready to connect the robot's foot rig to the reverse lock chain we've just built.