please have a look at the picture,this is not my project,it is a example from google,
In my project,the pants is one mesh,so how can i create the front walk animation like the example so that i can deal with some points' render layer to implement the effect which left leg and right leg move and mask?
Anyway I can change one point's render layer?
- Modifié
You can control the order that the triangles that make up a mesh are rendered by dragging the bones in the Weights view:
Weights - Spine User Guide: Triangle order
This can't be animated though. You could have 2 of the same mesh, where one has the left leg on top and the other has it on bottom. Or maybe you could make the line between the legs a separate mesh
it doesn't have to make sense in the physical world, it just needs to look right. 
If the pants look like the example, then you may want to simply deform the line that separates the two sides of the pants - either using a bone bound to the mesh, or directly by moving the vertices. However, separating one side from the other, and animating its draw order may also be a valid option.
Images - Spine User Guide: Draw order
Weights - Spine User Guide
Mesh Tools - Spine User Guide
thanks you all for the help.