Blender tips and troubleshooting

連番静止画から動画の作成方法　Scriptで簡単にできそう

• sequencer に切り替え、連番画像を読み込みし、movieに切り替えて render animation すれば C:\tmp に動画が作成された
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tips

blender tips 200

• 1 - absolute grid snap checkbox
• 2 - presets
• 3 - navigate hierarchy by [ ] (up and down)
• 4 - focus shift (alt+MMB click) not drag because it rotates the view
• 5 - ?
• 109 : i key to skip selecting location etc ( Timeline > Keying > Active Keying sets )

troubleshooting_blender

• get object in the scene by name
  • ob = bpy.context.scene.objects[“Cube”]
  • dt = ob.data

how_to_blender

numpyを扱う

• 

import subprocess

try:
    import numpy as np
except:
    command="pip install numpy"
    result = subprocess.check_output(command.split())
    print(result)
   
import numpy as np
A=[[1,2,3],[4,5,6]]
M = np.array(A, int)
for X in (M, np.rot90(M),np.fliplr(M), np.flipud(M)):
    print(X)
    print('-'*20)

Iteration - seelcted objects

• before-after  »

import bpy
for obj in bpy.context.selected_objects:
    obj.name='new_name'

shader node

• before-after  »

import bpy
mat = bpy.data.materials.new('Hoge')
mat.use_nodes = True
bsdf = mat.node_tree.nodes["Principled BSDF"]
texImage = mat.node_tree.nodes.new('ShaderNodeTexMagic')
mat.node_tree.links.new(bsdf.inputs['Base Color'], texImage.outputs['Color'])
ob =bpy.context.view_layer.objects.active    #
if ob.data.materials:    ob.data.materials[0] = mat
else: ob.data.materials.append(mat)           

• example after the script

import bpy
import math

START=0
END=100
N=5
bpy.context.scene.frame_start = START
bpy.context.scene.frame_end   = END

# Add a camera
bpy.ops.object.camera_add(
    location=(70, -40, 50),
    rotation=(1.1, 0, 0.8)
)

# Add color cubes
for x in range(0, N):
    for y in range(0, N):
        for z in range(0, N):
            # Add a color cube
            bpy.ops.mesh.primitive_cube_add( location=(x*3, y*3, z*3) )
           
            obj =bpy.context.view_layer.objects.active
           
            mat = bpy.data.materials.new('Cube')
            mat.use_nodes = True
           
            bsdf = mat.node_tree.nodes["Principled BSDF"].inputs[0].default_value = (x/N, y/N, z/N,1) # color
            bsdf = mat.node_tree.nodes["Principled BSDF"].inputs[18].default_value = 0.5 # alpha
            mat.blend_method = 'BLEND'

            obj.data.materials.append(mat)
           
            # Set the start key frame
            bpy.context.scene.frame_set(START)
            obj.keyframe_insert( data_path='rotation_euler' )
            obj.keyframe_insert( data_path='location' )
           
            # Set the end key frame
            bpy.context.scene.frame_set(END)
            obj.location = ( (N-x)*3, (N-y)*3, (N-z)*3 )
            obj.rotation_euler = (math.pi, math.pi, math.pi)
            obj.keyframe_insert( data_path='location' )
            obj.keyframe_insert( data_path='rotation_euler' )

animation

• example after the script for the selected object

import bpy

bpy.context.scene.frame_set(0)
obj =bpy.context.view_layer.objects.active   
obj.keyframe_insert(data_path='location')
bpy.context.scene.frame_set(20)
obj.location.z += 1
obj.keyframe_insert(data_path='location')
old_type = bpy.context.area.type
bpy.context.area.type = 'GRAPH_EDITOR'
bpy.ops.graph.interpolation_type(type='LINEAR')
bpy.context.area.type = old_type
bpy.context.scene.frame_end = 20

trajectory

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• example - https://github.com/jamad/blender_jamad/blob/master/animation_trajectory.py
• example - https://github.com/jamad/blender_jamad/blob/master/animation_trajectory.blend

light and camera

• example after script

import bpy
import math

# create a light
bpy.ops.object.light_add(type='POINT', radius=1, align='WORLD', location=(0, 0, 0))

# create a camera
bpy.ops.object.camera_add()

# create a plane
bpy.ops.mesh.primitive_plane_add(    location=( 1, 2, 3 ),    rotation=( math.pi/3, math.pi/4, math.pi/5 ),   )

逆引き

• タイムラインを　frame 0 に移動 ref
  • bpy.context.scene.frame_set(0)
• ‘target’という名前のオブジェクトを変数に登録し、位置と回転をゲット　ref
  • targetOBJ=bpy.data.objects[“target”]
  • pX,pY,pZ=targetOBJ.matrix_world.to_translation()
  • rX,rY,rZ=targetOBJ.matrix_world.to_euler(‘XYZ’)