We started off the lesson by talking about non-manifold geometry and different examples of it. One of the main types is when the mesh can have flipped normals on specific faces because the user has extruded an edge wrong or something is overlapping. Seeing the other side of a face results in a black face with no texture, that side of the face doesn’t really exist and so when modelling, it needs to be made sure that these can’t be seen.
We then started the process of creating an arm shape and applying a rig to it. First, I created a sphere to act as the shoulder joint, I then needed to create the upper arm, so I used a cylinder, rotated it so it was horizontal along the X-axis and lined it up next the sphere. I now had the upper section to the arm, I combined the two objects and named everything appropriately in the outliner (“Shoulder, Upper_Arm”). I then duplicated the object to create the lower arm with the elbow. I resized the objects a bit so they were overall smaller but the cylinder was a little longer to make the proportions a little more realistic. I then added a final, smaller sphere to the end to act as the wrist and a cuboid to the end to act as a hand. I then combined the lower arm and elbow and the wrist and hand and named them in the outliner.
I now had all the sections needed for a full arm, I decided to try moving the pivot points of each section to the joint to make sure everything moved properly and organised the outliner so everything was in the right place. Next, I went into the rigging menu and began the actual process of giving the arm a skeleton. I Began adding individual joints using the rigging tools, I started with the shoulder, dragged that out from the lower arm, and then a second joint for the elbow, dragged that out to create a lower arm and then ad a wrist on the end of that as the final joint.
I now had to parent all the shapes to the rig, I made a hierarchy with the joints so that they all controlled each other properly, The shoulder was at the top of the hierarchy with the elbow joint as a child and then the wrist joint as a child of the elbow, this way they would be able to move realistically with the wrist being able to move freely from the elbow and the elbow able to move freely from the shoulder, but not the other way round. I then put the shapes into the hierarchy so that they were all parented to the right joints, so the upper arm was on the shoulder joint, the lower arm on the elbow and the hand on the wrist. Finally, I deleted all the history to make sure no problems would arise later on.
I could now animate it to perform a simple wave. I began by animating the shoulder to move the whole arm in a slight waving motion by keyframing all the movements on the timeline, I then animated the elbow to move the upper arm more from side to side to create a rather enthusiastic wave, and then I animated the wrist moving the hand slightly from side to side, I tried some different motions, twisting the hand was an option but I prefer the look of it waving with the rest of the arm.
I now had a basic animation of a hand waving, I went into the graph editor to polish some things up, the acceleration looked pretty good but I did some cleaning up there and I also tweaked the values of some of the movements so they looked more natural with the rest of the animation, the animation was also a little slow so I sped it up by compressing all the keyframes in the timeline, so that the wave was quicker which made it look more enthusiastic and less robotic.
I then captured it with the playblast feature and had a final animation.
Maya Questions –
Name one thing that non-manifold geometry cannot do?
One of the negative aspects of having Non-manifold topology is that polygons cannot be unfolded into a continuous flat piece.
Describe 3 things that you can change when grouping objects together?
Group the selected objects together, Select a group. For both of these, you can transform, rotate and scale the selection.
Give an example of how or when you might use a parent-child hierarchy
A parent child hierarchy may be used when creating a limb such as an arm, here the hand will be a child to the lower arm, and the lower arm will be a child to the upper arm. Therefore, all the sections of the arm will move realistically with the upper arm moving the whole arm when rotating, the lower arm moving itself and the hand, and then the hand which moves independently.
Name 3 different combine options within Maya?
You can group, parent and combine objects in Maya, grouping will allow the objects to move together or independently depending on the what you choose to select. Parenting will allow children objects to move independently from their parent objects, but wherever the parent moves, the child will follow.
How might you use the selected options in your workflow?
If I wanted to move a selection of objects to the same place or scale them all equally, then using the group combination can ensure that they all transform equally. Parenting objects would be great for creating rigs as I could have all the objects move according to how I structure the hierarchy, giving me better control of their movement during the animation process. I may decided to straight up combine multiple objects if I wanted to create one large object, this could happen if I was creating one side of an asset, instead of making the other side form the start, I could duplicate the current object, mirror it and combine them both so they can be stitched together.
Describe two things that you should be aware off when combining geometry in Maya
You will need to make sure that when you combine the selections, that no non-manifold geometry is formed during the process as this will cause issues. You will also need to make sure that you are aware of where the pivot point is positioned as that will need to be moved after you combine multiple objects.