Full video#

Inroduction#

In this tutorial we will learn how to use weight layers to paint weights for a character. Painting a character is a complex process, especially areas influenced by multiple bones can be challenging particularly around the shoulders, fingers and face. We will divide this character into 4 simple layers, body, limbs, fingers and face to give the basic understanding of weight layers. But you can divide the character into more layers if you need to later.

• Body - It will include spine, neck and head bones and we paint their weights in the first layer.

• Limbs - We paint arms and legs in this layer top of the body layer. We mask the areas where the limb layer is influencing the mesh.

• Fingers - We paint fingers in this layer as a third layer.

• Face - And as a final layer we paint the face bones separately in their own layer at the top of the stack.

We’ll use this biped character to demonstrate the features of weight layers.

Body Layer#

Initializing

We’ll start by adding armature to our character with default weights. Now we can switch to Weight Paint mode and enable weight layers. When we initialize weight layers for the first time, it will come with base layer including the default weights of the armature. We will replace this weights with the new body weights later. We start with renaming this layer as body.

We exclude cloth bones that we don’t need for current mesh by disabling from bones panel. It eliminates unnecessary vertex groups in the mesh and improves performance. To have a cleaner list of bones we can use Hide Disabled toggle to hide disabled bones from the list.

Auto Weights

We lock all bones in this layer and unlock spine bones only. So when we set auto weights, all vertices will be assigned to closest unlocked bone which are spine bones in this case.

Paint Rough Weights

Now we can fine tune weights around neck and head. Just continue to assign absolute weights to bones. Always start painting with rough weights. Drafting the weights is useful because we can define weight boundaries more easily and see rough results quickly. We can smooth weights later. We mirror the weights to the other side with mirror button in the tools panel.

Smoothing

Once we done with rough painting, we smooth all weights in the body layer. Make sure we have All Groups selected in the smooth settings so it will smooth all bone weights together. You can increase factor and iterations to achieve smoother results with fewer clicks. Check test animations and continue smoothing until we get good results. We can also use blur tool to smooth the weights for each bone separately.

Limbs Layer#

New Layer

We add a new layer with empty weights and rename it to limbs. We lock all bones in this layer and unlock arm and leg bones. We set auto weights. We can see that when we play test animations nothing happens. This is because we need to mask the areas where the limb layer is influencing the mesh.

Masking

To make selection easier we can hide locked bones from filter menu. Then we select mask layer and start painting the limb areas. We start painting absolute values and we smooth the mask layer by checking test animations.

Paint Rough Weights

Now we can start painting the weights for the arm bones. Auto weights already gave us a good start. We just need to fine tune the weights to define the boundaries of each bone.

Smoothing

Once we are happy with the absolute weights, we can start smoothing the weights in the limbs layer until we get good results. At the end we mirror the weights to the other side.

Fingers Layer#

We follow the same steps for the fingers layer. We add a new layer and rename it to fingers. We lock all bones in this layer and unlock finger bones. We set auto weights, paint mask and then set clean boundaries for each bone. We smooth the weights until we get good results in test animations. We finish fingers layer by mirroring the weights to the other side.

Face Layer#

I won’t go into details for painting all face joints. It is a similar process to the previous layers. You can either paint face as whole in this layer or you can divide face into smaller areas like eyelids, brows, lips, nose etc. and paint them separately. I’ll just paint eyelids in this layer for demonstration purposes, once you get the idea you can continue painting the rest of the face. We start by adding new face layer. We lock all bones in this layer and unlock eyelid bones to be able to set auto weights. We paint mask and then set clean boundaries for each bone. And again we smooth the weights until we get good results in test animations.

Cleaning Up#

When we are happy with final results I recommend disabling the layers to save the file size and performance before delivering the final rig. This will bake all layers to vertex groups and remove the weights layers from the rig.

Conclusion#

As we experienced here, divide and paint is the best strategy for painting weights for characters. It is easier to paint weights in focused areas and also easier to debug and fix issues without breaking other weights already painted. I hope you find this tutorial useful and see you in the next one.