move specific verts then add shape key

Coding Python Support
1

Hey,

I have a set of points/vertices, I want to edit their location and add a shape key to catch the new location. I want to do this around 30 times. In the end producing an animation through keyframes. I am trying to test on a cube. My original simplistic thought was to add a shape key and then move a specific vert:


import bpy
#moves the first vertice in the cube down 4 units
o = bpy.data.meshes['Cube']
verts = o.vertices
v = verts[0]
bpy.ops.object.shape_key_add(from_mix=True)
v.co[2] = -5

but that didn’t work. It seems that a specific vertice has to be moved in an edit mode session for the shape key to work properly. So I tried selecting a specific vert inside an edit session. This is where I am stuck. I am unable to select a specific vertice inside an edit session through python. If anyone has any ideas on how to select a vertice inside an edit session through python or animate a field of vertices where each vertice moves in a specific direction every time step please let me know.

Any and all help is appreciated.

2

Selecting vertices has to be done in objectmode

…vertices[i].select = True

Self experimenting gives maybe a better start?


import bpy
#moves the first vertice in the cube down 4 units
o = bpy.data.objects['Cube']
verts = o.data.vertices
v = verts[0]
bpy.ops.object.shape_key_add(from_mix=True)
bpy.ops.object.shape_key_add(from_mix=True)
o.active_shape_key.name = "Abracadabra"
#this does not work yet ?
v.co[2] = -5
#I think you must create vertexgroups assign them to a shapekey and...???

EDITed
Removing all keys one can see that vertex 2 is at z = -5 :eyebrowlift2:

3

Problems solved :evilgrin: see attachment!

Attachments

shapekeypython.blend (64.4 KB)

4

PKHG props to you my friend, you are both a gentleman and a scholar. Thank you for helping me figure this out. It would have taken me forever to figure out that I needed to add as a vertex group. I can’t wait to play with this today, thanks again!

5

PKHG looks like the vertex grouping isn’t required. The key that you gave was the ability to select specific vertices in object mode. For this I am eternally grateful. Code to make a shape key of defined vertice locations is below:


import bpy
o = bpy.data.objects['Cube']
verts = o.data.vertices
v = verts[2]
for all in verts:
    all.select = False
v.select = True      #in object mode!
bpy.ops.object.shape_key_add(from_mix=True)     #Basis
bpy.ops.object.shape_key_add(from_mix=True)     #First Key
o.active_shape_key.name = "Abracadabra"
bpy.ops.object.editmode_toggle()
bpy.ops.transform.translate(value=(0, 0, -4), constraint_axis=(False, False, True), constraint_orientation='GLOBAL', mirror=False, proportional='DISABLED', proportional_edit_falloff='SMOOTH', proportional_size=1, snap=False, snap_target='CLOSEST', snap_point=(0, 0, 0), snap_align=False, snap_normal=(0, 0, 0), texture_space=False, release_confirm=False)
bpy.ops.object.editmode_toggle()