Continuing where we left of in the previous tutorial. We have the empty groups on our mesh, the tools are ready and we can start painting.
So how do I paint weights? The short version is this: paint an area, lock it, move to the next one, and so on until you are done. Sounds easy right? That's because it is easy.
Let me show you what that looks like in practice. I won't go over the entire body because there is no need for it. Once you figure out all the techniques I will show you, you can paint anything on your own.
Pelvis and spine weights
All groups are empty right now so let us start by weighting all points to the pelvis. Select the pelvis Bone and either paint using the Add hard brush, or assign them to the group in Edit mode. Both are fine and I prefer to go with the Edit mode route.
Instead of doing only spine_01 next, I like to block in the weights using Add hard for all of the spine Bones. As pointed out in the previous tutorial, make sure Auto Normalize is enabled and you can also enable Show Weight Contours and Wireframe. Then just paint the points that are the closest to each of the spine bones.
I used vertex select mode so I can paint in very broad strokes. You don't have to, the only thing that matters is that you paint only over the area closest to that Bone. Then you repeat the process for the rest of the spine to end up with something like this:
Notice how the last spine Bone is influencing all the geometry that is above it. This is really important so make sure you paint it the same way.
It is good to know what the smoothing looks like so first select the spine Bones and rotate them a bit.
Now we can smooth and see what we are doing. So select all the Bones you want smoothed, in this case pelvis and spine bones, enable the vertex select mode with the UI button or the V key, lastly select the area you want smoothed.
As you can see in the image above, I didn't select the whole chest and pelvis areas. Those areas don't bend much in real life so I don't want them to have smooth weights. The rest of the stomach can be smooth though. Now run the Smooth operator with the Subset set to Selected Pose Bones.
This gives us a great base to paint on. At this point I will start rotating Bones into different poses and refining the weights using Add soft mainly.
In this case, I am not a big fan of how smooth the top of the hip is so I will adjust it.
If the weights you paint aren't perfectly smooth, you can even them out using the Smooth operator. Just select the Bones, then the vertices in that area, and run Smooth.
I continue painting and smoothing. And from time to time also using the Weights>Normalize All operator to make sure everything is normalized properly. And when I am done, the torso looks something like this:
That is good and it can always be adjusted further once we have a rig on there. For now, we move on the next area.
Neck and head weights
In order to keep control of the weight distribution, we will first lock all Bones and then unlock the last spine Bone and the neck Bones. That way, the painting we do will only affect the last spine Bone and the locked weights will not get accidentally changed.
Then we repeat the same steps we took with the spine. First of those is to block in the neck weights using the Add hard brush. And since we have all the other Bones locked, we know that we are painting only over the last spine Bone's weights. You should end up with something like this:
Now rotate the neck Bones so we can see what we are doing, then select the last spine Bone and the neck Bones. Run Smooth and tweak it until you have something that looks nice.
The smoothing did a great job on the neck itself but as you can see in the image below, the transition between the neck and the shoulder is not looking good.
So switch to the Add soft brush and paint over that area. It is about balancing the weights between the spine and neck and making it look as good as you can. Check out this next gif to see what I am aiming for:
You might have noticed that I also painted the head weights too. Exactly the same steps. Lock the spine, block in head, smooth, refine. Here is the finished head. Notice how the transition between the head and neck is not that smooth. You want that head to feel like a solid block.
When refining the weights, try not to rush things. I constantly switch between the Bones that are influencing the area. Add some weight to the head, then pull it back by adding to the neck. Then maybe a bit of Smooth if needed. Move the Bones to check what it looks like in different poses and from different angles. Then repeat.
Check out how useful those Weight Contour lines are. You don't even need to look at the colors, just how straight or jagged the lines are and how they are spread across the geometry.
And if you are in a tight spot which is hard to paint, use vertex selection to mask what you are painting on.
The clavicle is where this weight painting method really shines. Mainly because we need to balance the weight between the neck, clavicle and spine. But since we have the neck doing exactly what we want already, we can lock it so we are only left with the job of balancing the rest of the weights between the clavicle and the spine.
To show you what I mean by that, first let me show you what happens when I paint weights for the clavicle without locking the neck first.
Not good at all. It just destroys all the work we did on the neck. I did it with the hard brush to prove a point but even if you paint carefully, the outcome is the same.
But, let us first lock the neck weights and see what happens.
That is much better. We are only able to add the weight that is available on the unlocked Bones, which in this case is the last spine Bone.
One warning, this doesn't work perfectly with the Smooth operator. Smooth doesn't really take locked groups into account properly and for that reason the weights can end up not normalized. And if you run Normalize All later with the neck unlocked, the weights will break.
This doesn't mean that you shouldn't use Smooth here at all. Just be careful with it and run Normalize All after smoothing to check if everything still looks good.
As a reminder, Normalize All can be found under the Weights menu and for this case it works best with these settings applied:
Alright, now that we know how to approach the clavicle let's paint it for real. So what do we do first? Yes, we block in the weights. Grab the Add hard brush and block in a nice chunk of the shoulder for the clavicle Bone. And don't forget to first lock every Bone except the last spine Bone and the clavicle itself.
I am sure you already see the pattern and how easy this process is. Just a few tools applied over and over again as we crawl along the mesh.
So after the blockout of course comes the smoothing. Select the last spine Bone and the clavicle, then V to go into vertex select mode, select something like what I have in the gif below and run Smooth on Selected Pose Bones.
Then pose the clavicle and check what can be improved. Keep an eye out for things like what is in the image below. Smooth didn't really do what we want there but it can easily be adjusted by doing a bit of painting.
After about 10 minutes of painting I have something I am happy with.
To be honest, there isn't much else to show you. Continue doing the same thing across the upper arm, then lower arm, hand and so on. Then repeat that down the legs.
But before we wrap it up, let me show you one more example. I will adjust the Bone display so it is easier to understand what I am talking about. I also went ahead and painted the weights for the arm but I ignored the twist Bones that are in there.
The reason I did it like this is that it allows me to focus only on the transition between the arm and shoulder, and between the upper and lower arm. Once that is done, it is easy to take the weights from the upper arm and distribute them to the twisty Bones.
So lock everything except the upper arm and its twist Bones and block in the weights. You should have something like this:
The last Bone I select in that gif is the upper arm Bone itself and the weights you see are what is left over after the twisty Bones are blocked in.
Only thing left do do is to select the upper arm and the twist Bones, the vertices that should be smoothed and run Smooth on them.
That might be a bit too smooth actually but we will test it properly once we rig the arm. It is easy to knock them back a bit by painting or if we repeat the same process.
There you go, you never again in your life need to worry about painting weights.
I plan to make at least one more weighting tutorial to cover things like layered clothing, meshes with thickness, transferring of weight between meshes and similar so stay tuned.
Don't hesitate to ask if you have any questions or if you need me to elaborate on something. I would love to hear how this method works for you and what you make with it.
For all the Patron's, thank you very much for the support. I have uploaded the Nonomoke model with the final weights so you can analyze how the full body is weighted.
Have a great rest of the day!