When creating a rotoscoped mask the new vertices can be dragged to make the line squigly and these little handlebars will appear. This was working well till i noticed that most of the vertices lock the handlebars so that the bars remain straight, but there are a couple vertices on my mask where the bars can be moved independently. Im looking to homogenize them, is there any way i can lock those couple vertices, or make all others work independently too?
You can change the vertex interpolation at any point by using the Convert Point Tool found under the normal path/mask/shape pen tools (shortcut G). Spline handles break, if you insert a point in a segemnt that already as non-uniform weighting at its end points because AE is not able to otehrwise retain those values. If you leave all points at their default "automatic" interpolation, newly inserted points will also have auto-tangent handles and AE adjusts the neighboring points along with it.