使用python脚本在Blender的关键帧处将对象链接到父对象

编程问答 2022-06-08

问题描述

我想在第40帧将对象链接到其父对象，然后在第80帧取消链接。我觉得它应该是这样的：

o.parent = p
o.keyframe_insert(data_path="???",index=-1,frame=40)
o.parent = None
o.keyframe_insert(data_path="???",frame=80)

谢谢！

解决方法

在谷歌搜索和实验之后，我提出了一个小例子，说明如何设置和取消（又影响）Child Of约束。

import bpy

def add_frame(oArgObject,sArgType,dArgFrame,sArgName):
    if sArgType == 'location':
        oArgObject.keyframe_insert(data_path='location',index=-1,frame=dArgFrame)
    elif sArgType == 'influence':
        oArgObject.keyframe_insert(data_path='constraints["'+sArgName+'"].influence',frame=dArgFrame)
    else:
        print('Unrecognized frame option: ' + sArgType)


def add_parent(oArgChild,oArgParent,bArgScale):
    sName = 'Child' + oArgChild.name + 'Parent' + oArgParent.name
    if sName in oArgChild.constraints:
        print('Constraint ' + sName + ' exists')
    else:
        oConst = oArgChild.constraints.new(type = 'CHILD_OF')
        oConst.name = sName
        oConst.target = oArgParent
        oConst.use_scale_x = bArgScale[0]
        oConst.use_scale_y = bArgScale[1]
        oConst.use_scale_z = bArgScale[2]
        print('Constraint ' + sName + ' added')


def set_influence(oArgChild,dArgInfluence): 
    sName = 'Child' + oArgChild.name + 'Parent' + oArgParent.name
    if sName in oArgChild.constraints:
        index = 0
        while oArgChild.constraints[index].name != sName:
            index += 1
        o = oArgChild.constraints[index]
        o.influence = 1 - dArgInfluence
        add_frame(oArgChild,'influence',dArgFrame-1,sName)
        o.influence = dArgInfluence
        add_frame(oArgChild,sName)
    else:
        print('No constraints exists for object ' + oArgChild.name)


bpy.ops.object.select_all(action='SELECT')
bpy.ops.object.delete()

bpy.ops.mesh.primitive_cube_add(size = 1,location = (1,0))
oParent1 = bpy.context.object
oParent1.scale = (0.5,1.0,0.5)
oParent1.name = 'Parent1'
add_frame(oParent1,'location',10,'n/a')
oParent1.location.x += 4
add_frame(oParent1,50,'n/a')

bpy.ops.mesh.primitive_cube_add(size = 1,location = (0,1,0))
oParent2 = bpy.context.object
oParent2.scale = (1.0,0.5,0.5)
oParent2.name = 'Parent2'
add_frame(oParent2,60,'n/a')
oParent2.location.y += 4
add_frame(oParent2,100,1))
oChild = bpy.context.object
oChild.scale = (0.5,1.0)
oChild.name = 'Child'
add_frame(oChild,5,'n/a')

add_parent(oChild,oParent1,(True,True,True))
add_parent(oChild,oParent2,(False,False,False))

set_influence(oChild,20,1)
set_influence(oChild,40,0)
set_influence(oChild,70,90,0)
blenderkeyframeparentpythonscripting