Animating the human mesh

[Adam Trachtenberg]

You would use joints to animate the mesh. In a nutshell, it works like this:

* from a front view, select the body mesh and then activate the character>joint tool;

* draw out the joints, starting from the center of the chest, by control clicking where you want to place them. So, click at chest, shoulder, elbow, and wrist/hand;

* then go to a side view and move the joints into the correct positions from that perspective;

That gives you your joints, lined up under the mesh, but you still need to tell Cinema how they influence the mesh points. That’s called “weighting” the mesh. And you’ll also have to create a Character>Skin object and place it in your mesh heirarchy. The Skin object is the deformer that applies the joint movement to the weights you will create below.

Weighting the Mesh

* add a character>weight tag to the body mesh;

* lock the attributes manager (icon at top right) and then drag the joints you created above into the weight tag’s Joints>Objects box;

* select all the joints in that box and click on the “Auto Weight” box. That’s just a starting point. It assigns point weights to joints based upon point proximity, so it won’t work brilliantly in a partially rigged model, or on models that don’t start out in the T-Pose (arms out to sides);

* now select the first joint in the object manager and activate the Character>Weight Tool. Turn off the character’s hypernurbs object if it’s in one — ohterwise you won’t see the weight display on the mesh;

* now you should see the mesh highlighted in areas of white and black. White means that that area’s points are weighted to the selected joint. You’ll want to weight the whole character to the chest joint, except for the arm that’s supposed to move. Weighting the shoulder is the biggest challenge;

* then you will select the successive joints and weight them to the appropriate points using the weight tool;

Rigging the Arm

Finally, you *may* want to create an IK rig for your arm. This allows you to drag a controller null and have the arm follow the null, sort of like a puppet.

* select the first joint in the chain (shoulder) and the last joint (hand/wrist) and run the Character>IK Chain command. That will set up your IK automatically. You’ll see that an IK tag was placed on the shoulder joint, and a goal null was created at the top of the heirarchy. When you move that null the arm will follow. Depending on how you did on the weighting, the arm will probably follow too. 😉

At this point you’ll most likely have to go back into the weight tool and fine-tune your joint weights.

hth

[Simon Roughan]

hey man, you’re the best! Thanks so much for your long and detailed answer. Im sure you’ve got better things to do, so again, thanks for your time. If youre ever in Heidelberg, the beer’s on me…
Simon