Open the scene for the lesson

1. Load the previous scene you worked on or load the tut_dragonLeg_paintBones_START.ma file.

   This scene contains the dragon leg with connected bones and capsule objects. The dragon leg mesh is set up with default Sticky weights applied to the capsules for basic skin deformation.

   You can use the Display Layer Editor to show and hide various parts of this rig.

Paint weights

After you apply default weights to the bones and polygon mesh objects, you can use the Muscle Paint tool to refine those weights. You can choose to raise or lower the effect of the default weights by further painting weights on the skin mesh.

1. Make sure the scene view shading is set to Smooth Shade All.
2. Select the skin mesh object (pSkinMesh) then select Muscle > Paint Muscle Weights.

   The Muscle Paint tool appears and the mesh displays in Paint mode, in a black color.

   The Muscle Paint tool provides many of the same basic features as the artisan paint tools. See Muscle Paint tool to learn more about its specific attributes.

3. Select Sticky from the Weights drop-down menu.
4. Select "jntShoulder" in the Influence list and turn Replace on.

   

5. In the “jntShoulder” or hip area of the dragon leg, paint weights to the shoulder (hip) bone.
   TipYou can press and hold down the "b" key while dragging in the scene view to adjust the size of the brush.

   

6. When you are finished painting weights, close the Muscle Paint tool and scrub the timeline. The points on the skin move when the capsules and bones move.

   In the next steps, you set weights on specific points, rather than paint them on the entire upper leg.

Set weights to specific points

1. Open the Muscle Paint tool and select the "jntLegUp" object in the Influence list.
2. Turn off Paint mode in the Muscle Paint tool.

   

   The painting features are now disabled in the Muscle Paint tool, and the points of the skin mesh appear.

3. Select the specific points on the upper leg where you want to set weights.

   

   TipUse the Lasso Tool for more precision when selecting points.

   Notice that the Live Update option is on. This means as you drag the Weight slider the weights update interactively. When Live Update is off, you can set the weight value, but the weight does not change until you click Set Weight/Flood.

   When you have multiple points selected and Live Update is on, the Weight slider automatically adjusts to show the average weight to the current object for the selected points. For example if you select some points where the mesh is black and where the mesh is red, the Weight slider shows the average value of those points.

4. Use the Weight slider to drag the value to 0.5. Notice that the color turns yellow to show this area has half the weight.
5. Continue dragging the slider up to 1.0. The selected points on the dragon leg mesh are now weighted 100% to the upper leg bone.

Smooth weights

In the next steps, you will smooth the transition between the shoulder (hip) and upper leg joint. To make sure weights don’t get re-normalized to other bones, you can lock weights for them all.

1. Clear your selection, then turn Paint mode on in the Muscle Paint tool.
   NoteIt's important that you have no points selected when you turn Paint mode back on. If you turn Paint mode on with some points selected, only those points are paintable. When you turn Paint mode on with nothing selected, the entire mesh becomes paintable again.
2. In the Influence list, select everything except for the jntShoulder and jntLegUp bones, then right-click and select Enable Lock/Hold Weight on highlighted items from the menu.

   A HOLD marker appears next to each joint, meaning the current weights for those items are locked and cannot be adjusted, even if you paint around that item. You can now safely smooth weights between the shoulder and upper leg only, since those are the only two joints currently unlocked.

3. Select jntLegUp in the Influence list, and turn on Smooth.
4. Paint along the top edge of the upper leg a few times.

   

5. Scrub the timeline to see the smoother deformation between the shoulder and upper leg.
6. Select all the items in the Influence list, right-click and select Disable Lock/Hold Weight on highlighted items to continue painting on other bones.
7. Continue to paint and smooth weights to the joints/capsules for basic rigid bone type skinning with the techniques you have learned in this lesson. Leave the weights on the polygon knee cap and blade at zero, as you can use those objects for Sliding effects in a later lesson.

When you are finished, you should have a basic skin setup with bones. You can load the tut_dragonLeg_paintBones_END.ma file to see an example of basic Sticky weights painted for bones.

Beyond the Lesson

In this lesson you learned how to:

• Paint sticky weights to bones using the Muscle Paint tool
• Apply weights to specific points on a mesh
• Apply Smooth weights for better transition between weights

Painting Sticky weights to bones or capsules gives an effect similar to Maya skinClusters. The main benefits of the Muscle skin deformer for this type of work is both the color feedback, as well as the ability to use other features of the deformer such as Sliding, Jiggle and so on as discussed in the following lessons.

In general, it is recommended that you first paint weights to only the capsules and bones on your mesh before working with muscles and Sticky weights. This can help keep your weighting structured and organized.