Rigging Bones? Please Read Carefully



  • Now here I purposefully ignored parts of my model so you can see what happens if you do that. These parts that were not given bones were still props and treated as separate from the figure. So I selected the parts that were treated as a prop and deleted them from the scene, leaving me only with the figure.

    Now, technically, the character is rigged but of course, it's not rigged well. We'll move on to joints and weights in a moment.
    0_1461629896122_setup005.png



  • Ok, so now that you're back in the Pose room, it's time to start testing your model and determining what needs tweaking, what needs adjusting and what's just plain broke.

    Grab the Select tool and methodically go through each body part, turning the sliders for X Rotate, Y Rotate and Z Rotate to see how they affect your body part. Depending on your figure's body part positions, these rotations will represent the Twist, the Side to Side (front-back), and Bend (up - down) of your body part. Usually whatever rotation is first is the Twist. You can reorder these rotations using the Joint Editor but for now, just run the check to see how each rotation works with the body part.

    As you can see, my forearm's Twist is on the X axis but is twisting the arm in a really distorted way. Why is this? The reason is simple, the body part's Joint centers aren't aligned to the axis of rotation. So how do you fix this? You open up the Joint Editor (found under the Window menu) and you hit the Align button. This should resolve your problem but if it doesn't you can also manually adjust the center and end points to try to tweak things.
    0_1461630905110_setup006.png
    0_1461630968563_setup007.png

    Now hit the Zero Rotations button on the Joint Editor or the Figure>Zero Figure menu option to restore your figure to a zero position. With the select tool, go through each body part and hit the Align button so that you minimize the amount of work you'll be needing to do to get your figure working.



  • So now that you have your joints relatively aligned, it's time to look at the exclusion/inclusion deformers for each rotation (x,y,z). Select a body part (for my example I'm choosing the left collar), turn on the Joint Editor if it's not turned on and Click where it says "Center" and in the pull down menu that shows, select one of the rotation dials (I chose the z rotation). My ex co-worker thinks you should always do the twist first but honestly I don't think it matters.

    Now rotate the body part to a somewhat extreme level but don't get crazy. If the part in real life does about 15 degrees rotation, start off at 30 degrees not 100 for your tweaking. :) As you can see, I rotated the lCollar by 45 degrees. However, because the inclusion angle (the distance between the red and green lines, is so wide on the lower part , it is grabbing a bit more than it should, making the rotation apparently tear the figure.
    0_1461631939702_setup008.png

    In order to fix this, I'll need to adjust the angle the lines are separated at. To do this, I'll need to click on the end of the red line and move it toward the green. I may also want to move the green line (in fact, I actually did) but you may not need to - this really depends on the figure in question.
    0_1461632140683_setup009.png

    Now this looks much better but I think I can make it a little better by dragging the center point of the angle lines and moving that closer to the middle of the chest area where the clavicles meet and maybe adjust the lines a little more. So I'm going to give it a try because if I don't like it, I can undo it. Let's see:
    0_1461632320561_setup010.png

    Yup, I like this a little more. Now, I'll need to go through all the body parts three rotation options and do the same. NOTE: the twist appears as a single line that moves in and out only.
    0_1461632592253_setup011.png



  • 0_1461634892755_setup012.png So clearly the twist is a little to strong in the collar area. How to fix it?! Well, in older versions of Poser you'd use Spherical Fall Off Zones or Capsule Fall Off Zones. Those can still do the job but there's a less tedious method you can use in Poser: Weight Mapping. Now I forget if Poser 11 allows you to paint weight maps or if that's only a Poser Pro feature but I'm going to proceed as though you can because the other methods take longer and it's late here in NYC.

    Now when you select a body part's rotation with the Joint Editor Active, you'll be able to click the ADD button to add a weight map. There's a few different options when you do this, "Add sphere zone" (we don't want it), "Add capsule" (nope), "Add weight" (debatable) and "Merge Zones to Weight Map (my personal fave).

    Choose Merge Zones to Weight Map. You'll see that you're now working on WeightMap_0. Click the Paint Brush icon to begin painting your weight maps.

    With weight map painting, the darker the color the less the influence it has. 100% green means full influence, dark purple or black means no influence. So if you want to remove or decrease the influence of a rotation on a part of the mesh, you'll want to use the Subtract option on the brush. If the transition is causing creases or distortions, use the Smooth option to smooth out the transition in colors. Obliviously the Add option allows you to paint more influence into an area. The Weight option allows you to paint a specific and uniform amount of influence.

    ok, so that's the basics of what options you have, there's more but that's more advanced than I have time to get into. So I'm going to paint out some of the influence of the twist using a combination of Subtract and Smooth based on how I think the joint influences the body in the real world.

    0_1461634955128_setup013.png



  • Ok, so now we have the Twist basically setup, let's take a look at that Zrotation again. It's a bit too strong in places and isn't affecting neighboring body parts like the neck enough. There's a bit of a reason for that second part: we haven't turned on Affected Actors for the body part. I'll cover all that in tomorrow's post. For now, I'm putting this on pause.



  • @Teyon said in Before you can paint a weight map on your new figure you'll have to first make it a Poser Unimesh. Go to Figure>Skinning Method>Poser Unimesh.

    Teyon, just a note, but I never use Unimesh to paint weight maps. Is this a new development in P11?



  • @Glitterati3D

    No, I actually mixed that up with subdivision. I'll edit it when I get a moment. I was pretty tired last night.



  • Hey,
    Been under the weather, sorry I haven't gotten back to this yet. As soon as I'm feeling better I will.



  • So if we look at the Z rotation on the collar, we'll see that it's neighboring body parts include the chest, the shoulder and (on my figure) neck1. We're going to want to add some of these as affected actors for the collar. In particular the neck 1 actor the chest should already be an affected actor for the collar because it's the parent of the collar bone.

    0_1462041949061_setup014.png

    Now, when deciding what to make an affected actor, you should consider what each rotation of a body part may affect in motion. So for example, the Left Collar bone directly impacts the chest, shoulder and to a lesser extent, the neck. HOWEVER, we may need to also add in the abdomen if considering how the latissimus dorsi moves when raising and lowering the arm/shoulder. So for the lCollar, we'll make neck 1 and the abdomen affected actors of the Collar.

    0_1462042061361_setup015.png

    A quick note about affected actors and weight mapping:

    You should try to decide what your affected actors will be before turning on weight mapping for a body part. This will help avoid the need to repaint maps if they originally didn't take into account the relationships of the affected actors.



  • Once we've got the affected actors assigned, we can choose from the Add menu in the joint editor: Merge Zones to Weight Map.
    0_1462042341770_setup016.png

    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.

    0_1462043414735_setup017.png



  • @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.
    0_1462044327519_setup018.png



  • 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.

    0_1462044897783_setup019.png

    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.

    0_1462045247168_setup020.png

    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.
    0_1462692385096_setup021.png



  • 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.
    0_1462692949386_setup022.png
    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.
    0_1462693063472_setup023.png
    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.
    0_1462693629081_setup024.png



  • 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.
    0_1462827957517_setup025.png

    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.
    0_1462827970947_setup026.png



  • 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.

    0_1462835856014_setup026.png

    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.

    0_1462836713298_setup027.png

    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...

    0_1462836876476_setup028.png

    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.
    0_1462837283541_setup029.png