This week we covered rigging with using Armatures, as well as a bit of weight painting.
Rigging with Armatures
So for learning about this we were given a Robot and we had to set up its skeleton in a similar fashion to how we did it last module, with some little changes that let us set up the controllers.
First you set up the bone in the centre to be your Master controller, then build up your skeleton (making sure it sits in the centre of the body part, and that the balls are where your body parts will rotate). Then once these were all in the correct spots, name them and symmetrize (making sure your model is on the X axis so this can flip).
Then instead of parenting these bones to our model with automatic weights, we instead use ‘with empty groups’ this will mean that we can select elements of the model and pair these to certain bones (since automatic weights will move our robot too organically with its deforms). Then by selecting the armature and the model we can go into edit mode and look at the vertex groups, and start selecting the areas that match our bones to assign them together.
Then I went ahead and changed these bones for ease of use, going and changing the elements to cubes, circles or spheres.
Then we went through and looked at bone constraints, I did this already when practicing the tilt control from last week, this copy rotation was to just have both of these claws move at the same time, and then giving a limit rotation to these as well.
IK Movement
So, the first time I tried to set up the IK movement, I didn’t really get to hear the exact way to do this and so I set it up wrong as seen below. It still looked pretty cool, but I made sure to note down to do another pass on this.
When I got home I did in fact go through and apply this correctly.
Basically, when you first hook up our armature, you will move your character with FK, Forward Kinematic, where the movement will follow from parent to child. With IK, Inverse Kinematic, you can focus more on actions like grabbing with out doing the awkward rotating of all the joints up the chain since instead of parent to child, we go child to parent as the movement travels up the chain. To set this up we extrude out a bone after our last bone we want to control, and then we also extrude out our Pole control from the elbow joint erasing deform and making sure these are just parented to the master control.
Then just make sure your pole is facing towards the controller with its X axis, and give the elbow a nudge in that direction so it knows where to bend. Then the IK is set up, to finish I just set up the wrist to rotate with the IK controller as well as setting up a driver so that I could easily turn the IK influence off by creating a custom property (I learnt how to do this when setting up the Squash and Stretch from Mike’s Tilt Cube tutorial).
And this is my little guy!
Weight Painting
Then we got a brief introduction to weight painting, basically telling Blender what verts to pick up to what bones. The automatic weights in Blender are generally good, but sometimes might need tweaking and this is done by painting using normalisation (so that certain elements are controlled by certain bones and they don’t overlap with these extreme strengths.
I found this a bit weird to wrap my head around but I had fun nonetheless, We were given a broken weighted rig with some animation to practice correcting like our other exercises, and this was what I had done by the end of the class. It isn’t perfect but it definitely is a lot better with deforms than the original file, and I had a bit of fun playing around with these new tools.
SOund Warning: the below clip has a weird buzzing noise so mute before playing!
Overall, I am having a lot of fun learning about rigging, and while I am still a bit worried and confused to start on my own model I can’t wait to be able to control future characters I make and discover all the things I can do to optimise them.