Introduction:
In this week’s blog, I’ll first be speaking about what we learned during this week’s lecture, which focused on skinning, and weight influence in Maya. Secondly, I’ll be talking about my process when completing the workshop my lecturer set out for us in class. The workshop was more or less a continuation of last week’s workshop, where we had to spread the joints’ influence evenly throughout the character geometry, and then further smooth the joints’ influence, minimising the creases within the character’s geometry.
This Week’s Lecture:
In this week’s lecture, we looked at skinning in Maya. Skinning is the process of connecting geometry to joints and then weighting the fall off. This process consists of connecting the joints to the vertices using a skin cluster node. There are two initial binding options.
Interactive Weights
In interactive weights, each joint can influence any vertex up to a value of 1 (100% each). The total value cannot drop under 1.
Post Weights
In post weights, the shared relationship between a vertex and any number of joints adds up to 1 (100%). Cannot drop under a value of 1 in total.
Our lecturer provided us with the list of stages that he’ll take us through when we bind geometry and paint weights for our workshop.
- Bind: Bind to selected joints (Not the whole hierarchy)
- Clean: Send all weights to one joint to clean up
- Break Apart: Create a ‘broken bind’ (Groups of vertices sent to their closest joint)
- Mirror 1: Mirror the broken bind to clean up
- Blend: Blend weights by selecting loops/vertices and using value and flood
- Polish: Paint smooth weights if necessary (With unused joints locked)
- Tweak: Hammer weights to tweak
- Mirror 2: Mirror the final weighting
- Additional: Add corrective shapes
Our lecturer chose to split this workshop into two separate sessions as there was a lot to go through and he didn’t want us to rush through any stage. So we began the workshop in our class, beginning with binding and cleaning. However, I wasn’t able to follow every step, unfortunately; therefore, I decided to complete this workshop at home, from start to end, using the recordings.
During the lecture whilst we were working on our workshop task, our lecturer came over to us individually to speak about any potential ideas for our assignment project. I mentioned to him that I was considering doing a title sequence that has a strong narrative behind it. He gave me a good suggestion, saying I could try taking a novel I’ve read a or video game I’ve played that hasn’t been made into a movie yet and create my adaptation of the title sequence. He said it would be a good challenge if I could do this, whilst staying within the restrictions and keeping my animation aligned with the novel/video game’s brand.
This Week’s Task:
Our task for this week was to finish the workshop from our lecture. Besides this, our lecturer suggested that we should also give more thought to what we would like to create for our assignment project.
In the first recording of the workshop, we went through the first two stages, bind and clean. I opened up the workshop file, and there was a character model with its rig ready for me to begin skinning.
Following what my lecturer did during the recording, I first went around the character model, selecting specific vertices, and connected them to specific geometry areas using the ‘Bind Skin’ tool.
Once the entire character model was rigged and connected to their specific joints, I next had to clean them individually as the weighting wasn’t spread correctly. As you can see in the screenshot below, the geometry looks off as I rotate a joint.
To clean up, we used the ‘Paint Skin Weight’ tool to go through individual joints and divide the weight among those joints.
To speed up the process, we cleaned up the weight painting only on one side of the character model, and then mirrored the geometry, using the ‘Mirror Skin Weights’ tool, meaning the skin weights were automatically cleaned on the other side of the character model.
Now that I’ve mirrored my geometry and all joints now had their influence spread correctly. It was time for me to go into the joints individually again and smooth them. To speed up the process, I planned to complete the left side only, as I’m going to mirror the geometry again at the end, so it also applies to the right side.
I began with the fingers first. If you compare the screenshot above to the screenshot below, you can see that the joint’s influence has been smoothed out on the edges, meaning there’ll be less of a crease in the geometry once the joint rotates.
To make sure I evenly smooth the joint’s influence, I decreased the value to 0.1 and used the flood button to apply the weight to the selected vertices.
I went around and repeated this step to all joints found within the left side of the geometry.
For the geometry that is found in tight spaces, it may be difficult to spread or smooth the weight correctly, as the weight could lean towards one side more than the other. For the space in between the fingers, I selected the vertices that looked off and used the Weight Hammer button to even out weights in that section.
Once I fixed the influence of the weights in between the fingers, I continued to smooth out the remaining joints’ influence.
In some areas, I found that smoothing the joint’s influence could still result in some harsh creases. Therefore, I used the brush tool to manually smooth those edges that were responsible for the creases.
The screenshot below is an example of how off-looking creases can appear if not smoothed properly.
The screenshot below is an example of how off-looking creases can be fixed once smoothed properly.
After I had smoothed and was satisfied with all joints found within the left side of the geometry, I selected the entire geometry and mirrored it the same way as I did previously.
After I mirrored my geometry, all joints found within the right side of the geometry now consisted of the same smoothed joint influence as the joints on the left side of the geometry.