In this video, we are going to take a look at using CAT's Add Bone feature to create muscle control for our character. But first, we want to finish utilizing the ribcage hub as we have one more system to add to the rig. This will be another spine that we will use for our neck and head. First, let's select our ribcage hub, and then coming over to the Modify panel, we'll choose the Add Spine command. Grabbing the hub, let's just rotate this into place and then approximately position it with our concept art.
Because of the simplicity of our design, we only really need three joints for the neck. So, let's select a spine joint, and then coming over to our Spine Setup rollout, we'll just lower the number of bones to 3 and press Enter. As we have been doing all along, let's just position each of our spine joints, again, just using our Move tool. Of course, in our rig, these are not really spine bones, they are neck bones. So, let's just name them accordingly.
Coming back over to our Modify panel, let's scroll to the top, and in the naming field just in front of the number, let's type Neck and then an underscore. I just want to copy this text so we can reuse it later on. But before leaving, I'll just add another underscore after the number 3, and then press Enter. Let's come to our second spine link and paste in our name and add an underscore, and then we'll repeat the process for the final link in the chain, again, pressing Enter when we are done.
For my personal taste, I prefer to make my neck joints just a little smaller, so let's set the X and Y fields to values of 20 and 9, and obviously we want to do this for each of our neck joints. Let's also make sure we name our new hub. Let's select it, and in the field we'll type Head underscore and then press Enter. I also want to change the size of this bone, but I'm just going to adjust the Width. I'm going to set this to a value of 29.8, and this is just going to fill out the volume a little bit.
I'll also just slightly tweak its position now that I've changed its size, and I also want to change its color. So, let's come back over into our Hub Setup rollout and click the Color Swatch, but this time I'm going to use RGB values of 166, 201, and 239, and just click OK. We now have a basic head for our character, but we won't get much articulation from just this single bone.
We may want a little more control than just the ability to move the whole head. What we want to do is add extra bones that will give our animators the ability to control the muscle of our character. To create these bones, we'll make sure our head is still selected, and we'll come into the Hub Setup rollout and click the Add Bone button. Depending on the scale of your rig, you may or may not see the bone we have just created. If we don't, we can simply come over to one of our viewports, and using the F3 command, we can turn our viewport into a Wireframe view.
Now that we can see through our head bone, we should be able to spot our newly-created bone in the center. I'm just going to press F3 to come back to our shaded view, and then I'm just going to align this bone with the upper jaw of my character, again, just using the Move and Rotate tools. While I'm here, I'm just going to adjust its size as well, setting the X and Y values to 20 and 9 respectively, and then just pressing Enter. Even though we are now working with a custom bone, we can still use Copy/Paste functionality.
In this instance, we will use the bone Copy/Paste functionality. With the bone still selected, let's choose the Copy command, and then selecting our head hub once again, we'll choose the Add Bone button. With the newly created bone selected, let's choose the Paste command. At first glance it appears our bone has disappeared, but don't worry, all it has done is taking on the characteristics of our original bone. Let's just move this bone into a better position, and using the Rotate tool, we'll just match our concept art in the background.
Instead of adjusting the size of this bone numerically, I'm instead going to use the Scale tool by pressing the R key. Before I scale the bone, though, I'm just going to change the Reference Coordinate System over to Local, that way we can just scale along the bone's axis. As I do so, I want you to pay attention to the X, Y, and Z fields over in the Bone Setup rollout. Usually, scaling an object outside of a sub- object selection can cause problems inside 3ds Max.
You will notice, as I use the Scale tool, all CAT is doing is updating the bone's parameters, which is very different from typical 3ds Max behavior. We can even add another bone onto a custom bone by simply selecting it and then coming over to the Command panel and clicking the Add Bone button once again. Let's just move and rotate this new bone into position. A nice feature of this Add Bone approach is that if I grab our original bone and rotate it, you can see the two bones are linked together and ready for animation.
Although we have just added three bones to our head, we are by no means limited to just these. In fact, we can add as many extra bones as we like and then shape and position them using the tools we have shown. This gives us creative freedom to build any type of rig we need.
- What is CAT?
- Using and editing preset rigs
- Repositioning bone pivots
- Using CAT control gizmos
- Working with spines
- Adding limbs to a character
- Working with adjustment and motion layers
- Animating with the foot pivot system
- Building a start-to-finish rig with CAT