Rigging Bones? Please Read Carefully

  • Once we've got the affected actors assigned, we can choose from the Add menu in the joint editor: Merge Zones to Weight Map.

    Normally this is used for collapsing the influence of a spherical or capsule fall off zone into a paintable weight map but you can (and I prefer it) do this to just make a weight map without using either of those.

    So now you can begin painting your weight map. Just like before, green is full influence, black is none and everything in between is, well, in between. What I'm going to try and do is to use the weight influence to thin down some of the latissimus dorsi when the collar is raised to help make it look more natural. I may need to also use bulge maps but we'll get into that later.

    Here's a shot of the lCollar after weight painting. It's definitely better than it was but it can use some finesse. To do our finesse work, we'll make bulge maps.


  • @Teyon

    Now bulges in Poser are interesting things. They can work with and without weight maps and are used to push in or bulge out areas of a mesh during bone rotation. You could use them to simulate the bicep bulge for example. In this case, we're going to use a bulge to reduce the mass of the latissimus dorsi as the collar is raised.

    To start, in the Joint Editor, you'll need to click on Apply Bulges for the rotation you're working on (in this case, zrotation), otherwise, any bulge adjustments you make won't be visible on the mesh. Now that you have them turned on, let's make some bulge adjustments. Fiddle with the sliders (right neg, right pos, left neg, left pos) to get a feel for which ones you should be adjusting and which you can leave alone for now. In my case, I need to adjust the right pos slider. I've given it a value of -.1 for now but that may change. The reason I went negative with the value is because I want it to bulge in, not out.

  • Now, this isn't really what we wanted to see, so let's turn on weight mapping for that bulge and try smoothing it out a bit by using a combination of the Add and Smooth vertex weight paint options. One cool thing about painting bulge map weights is that you don't have to stay in the initial area you start from. For example, I started with the intent of just fixing the appearance of the lats but I felt the chest could use some love too, so I painted on that area also so that the bulge had a subtle influence there. I think it turned out well.


    Periodically, it's a good idea to test the motion of your part while painting weights and bulges. Do so now and see if you like the result. If for some reason you don't, you now should have some idea as to how to go about tweaking the look.


    I'll return next week with how to deal with ghost bones. Hint: it's basically the same as regular bones but with the affected actor step first.

  • @Teyon I'm planning on reading & applying what you've said so far as soon as I have a real moment for it. ... Would you believe I run a web comic that has me using Manga Studio regularly?
    When I start to use this, I'm going to show my actions in screen shots too, just so if I foul up it's apparent why.

  • @Teyon said in Rigging Bones? Please Read Carefully:

    I'll return next week with how to deal with ghost bones. Hint: it's basically the same as regular bones but with the affected actor step first.

    Thankyou Tenyon, a real step by step guide. you made it very easy to understand. Waiting for your ghost bone tutorial. Thankyou again. Pat :)

  • Glad it's helpful.

    Now, Ghost bones are interesting because they are bones that have no assigned geometry at the outset. What this means is that you can't use the Select Tool, translate tool or any other tool to directly select the bone. Instead, you have to select it from a pulldown menu. See the image for an example of how I selected the ear ghost bone.

  • Now I have the bone selected but if I move the X, Y or Z Rotate, it's not just affecting the area of the ear, it's affecting the entire head. Obviously, this is undesirable behaviour, so we'll need to paint some weights to control how much of the head is affected. Once again, we'll want to use the deformers to help get us started. I'm going to work with the xRotate, which is the twist for my model's ear.
    Twisting the ear with the xRotate shows that while the affected area is now lessened, it is still grabbing more than what should be moved, so we'll need to make a weight map.
    Using the Subtract and Smooth options on the weight painting tool, I remove the unwanted vertices from the weight map and then smooth the area of where the wanted vertices and the rest of the head meet. This is done just to improve the look of the motion a bit.

  • Now that we have the twist setup we can use a nifty feature in the Weight Map editor to copy the weight map from the Twist and paste it into our other rotations for the ear to help speed things up. So at the bottom of the Vertex Weights window, you'll see a button that says Copy/Paste. Hit the button and choose Copy.

    Close the Vertex Weights window and then switch to the Y rotation for the ear. Now open the Vertex Weights window by hitting the paint brush in the Joint Editor and this time hit the Copy/Paste button and choose Paste.

  • Once you've done that, test the motion of the Y rotation on the ear. In my case, it bends in the middle of the ear instead of at the point it joins the head.


    To my taste, this is not desirable behaviour (note that some of what is "right" is a matter of taste in rigging). Now I have a few options. Simplest: I can edit the weight map so that the ear is more fully influenced than it currently is (ample use of Add and Smooth). I can delete the Weight Map, alter the position of the inclusion/exclusion lines of the deformer and then try again or I can decide to leave it as is. I'm going to delete it and start over.

    When working in 3D, be it designing, modeling, texturing, rigging or animating, it's important not to treat your work as too precious to alter. You have to be willing and ready to scorch the earth and start again if needs be - though rarely does such a need arise. Usually you'll find that there may be a better way to do something and you will always have that option to explore if you wish. Of course, if you're on a deadline and working for an employer, that allotted time may be greatly reduced, in which case you'll have to do what you can with the time you have. Regardless, be prepared to make changes.

  • So to start, I zero rotations and hit the Delete option for the weight map. Then I adjust the inclusion and exclusion lines so that they include more of the ear while excluding more of the head. It still won't be perfect but that's ok. I'll clean it up in a bit.


    Now I'll choose Add and Merge Zones to Weight Map. Then I'll do a quick test of the motion to spot just how good or bad the current weighting is. Based on the way the vertices are highlighted, I'm guessing the lower part of the face is going to move more than I want...


    Sure enough, it does but it also is moving with a pivot exactly where I had hoped it'd be (the connection from head to ear) as opposed to where it had been moving previously (the center of the ear). Now I just need to use the Subtract option for the weight painting and remove the lower part of the face I want to keep static.