I have made a script for adding VertexWeightMix modifers to a selected mesh. However, when I run the script, it adds tons of modifers, but only changes the first one it adds. How can I fix this? I don't want to apply them immediatly once a modifier is created.

for vertex_b in namelist:
    vertex_a = "bone_01D2"
    vertexA = bpy.context.object.vertex_groups.get(vertex_a)
    vertexB = bpy.context.object.vertex_groups.get(vertex_b)
    if vertexA is None:
        print("Vertex " + vertex_a + " Does not Exist!")
    if vertexB is None:
        print("Vertex " + vertex_b + " Does not Exist!")
    bpy.context.object.modifiers["VertexWeightMix"].vertex_group_a = vertex_a
    bpy.context.object.modifiers["VertexWeightMix"].vertex_group_b = vertex_b
    bpy.context.object.modifiers["VertexWeightMix"].mix_mode = 'ADD'
    bpy.context.object.modifiers["VertexWeightMix"].mix_set = 'B'

Edit: I figured out that if you declare a variable i = 0, then you can convert it to a string, append it to the name, then increase it. However, if I ran it again, it would not work.


1 Answer 1


I can just grab the length of the number of modifiers and then subtract it by one to get the index.

        bpy.context.object.modifiers[len(bpy.context.object.modifiers)-1].name = name
        bpy.context.object.modifiers[len(bpy.context.object.modifiers)-1].vertex_group_a = vertex_a
        bpy.context.object.modifiers[len(bpy.context.object.modifiers)-1].vertex_group_b = vertex_b
        bpy.context.object.modifiers[len(bpy.context.object.modifiers)-1].mix_mode = 'ADD'
        bpy.context.object.modifiers[len(bpy.context.object.modifiers)-1].mix_set = 'B'
  • $\begingroup$ In as much as this "works" I wouldn't do it this way. Can add a modifier to any object ob with m = ob.modifiers.new("name", 'TYPE') set properties on the newly added modifier via m.prop = foo. Please take a look at blender.stackexchange.com/a/132861/15543 for an example. Also the last item of a list can be indexed via foo[-1] $\endgroup$
    – batFINGER
    Nov 12, 2019 at 12:51

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