Automation with Blender: python:blender

Get Python Qt setup in Blender

UPDATE: 2020/06.23 install PySide2 for Blender 2.83

  • go to Blender install folder, D:\YourPathToThat\blender-2.83.0-windows64\2.83\python\bin
  • copy the path, and go commandline (type D: enter if your blender in D drive, C drive no need):
    • for Mac and Linux, same, just cd to that directory, and do above. the drive letter thing is just for windows, if you prefer to put app in other drive
    • run command code
      cd D:\YourPathToThat\blender-2.83.0-windows64\2.83\python\bin
      .\python.exe -m pip install PySide2
    • for mac, change version number accordingly
      /Applications/ -m pip install --upgrade pip
      /Applications/ -m pip install pyside2
  • restart blender, you should be able to call “from PySide2 import QtWidgets,QtCore,QtGui” without issue

Common Task in Blender

set camera clipping distance

  1. viewport, press N, to bring up tool panel, in View tab, set the far clip distance

Blender Shortcut

  • right click on any menu item, you can choose “create shortcut” from there
  • check all shortcut in Edit > Preference > Key Map

CG App Shortcut Compare Table

viewport Blender Maya
quad view ctrl+alt+Q space
view switch numpad,ctrl+numpad space+RMB markmenu
expert mode ctrl+alt+space alt+F10 ctrl+space
max. panel ctrl+space ctrl+Up space
tool panel T,F6 ctrl+A
property panel N ctrl+A
view selected num. f
isolate selected shift+h use icon
view all home a
- MMB centric alt centric
rotate view MMB drag alt+LMB drag
pan view shift+MMB drag alt+MMB drag
dolly view ctrl+MMB drag alt+RMB drag
add object shift+A menu shift+RMB markmenu
select all/none a double click/click none
drag select, add,remove,toggle b
LMB drag
MMB drag
ctrl+shift drag
ctrl drag
shift drag
paint select c
soft select o
obj/vtx,edge,face mode tab,ctrl+tab1,2,3 RMB markmenu, script
hide operate axis handle ctrl+space q
UI interaction Blender Maya
tear off panel left-corner cross sign + shift LMB drag just drag
swap panel left-corner cross sign + ctrl LMB drag -
slider UI hold ctrl =10% incr
hold shift = 1% incr
press E to overshoot
hold ctrl = small incr
middle drag in view
Action Blender Maya
wireframe on shaded object property : display : wire+all edge view menu : wireOnShade check, script
wire/shade view z 4
snap toggle shift+tab
snap menu, 3d cursor shift+S
vtx, curve, grid snap incremental snap + grid align btn hold v, c, x
delete obj x, delete delete
undo ctrl+z ctrl+z
redo ctrl+shift+z ctrl+y
Duplicate object shift+D ctrl+D, shift+D
duplicate as instance alt+D ctrl+shift+D w option
repeat last action shift+R g
adjust last action F9
hide object / unhide H, alt+H ctrl+H, shift+H
increase/decrease component selection ctrl+Num+/- shift+</>
to shell selection L
select all/none a double click/click none
continue selection ctrl+select shift + double click select
loop selection alt+select double click select
convert bet obj type alt+C
combine objects ctrl+J
separate object
center pivot ctrl+alt+shift+C
parent, unparent ctrl+p,alt+p p, shift+p

Blender Special shortcut

move obj to layer m
curor/selection grid snap shift+S
select border edge ctrl+shift+alt+M
cursor to origin shift+C
zero T,R,S alt+G,alt+R,alt+S

modelling shortcut in blender

fill hole=insert face f, ctrl+f
extrude edge, face, vtx e, ctrl+LMB end click
offset=insert face i
subdivide w
insert edge loop=loop cut ctrl+R w scroll
offset edge loop ctrl+shift+R
bevel ctrl+b
cut face=knife k
merge vert menu alt+m
average vert=smooth vert
edge menu ctrl+e
face menu ctrl+f
vert menu ctrl+v
set normal to face ctrl+n

Blender 2.6

Blender is 2nd 3D application I picked up when I was starting the 3D learning. (Cinema 4D is my first 3D app, Maya is my 3rd, 3DS Max is my 4th).

Before 2.6, the Blender interface is the most struggling thing to cope with,

  • short named buttons
  • unconventional shortcut oriented operation, wield layout

But now, as 2.6 comes with a new interface, it pops up and let you use optional Maya user interaction;

Now I started to pick it up again.

Before Blender 2.6

  • number pad
  • focus on selected: Num (.)
  • display vertex count: viewport overlay icon on View3D, check statistics
    • for show selected vertex count: select object, shift+h to hide other, view count, then alt+h/undo to show all

bounding box display:

  • select the objects to show bounding box:
  • go Property panel > object property tab: viewport display section
    • check Bounds or choose Display As = bounding box, right click corresponding UI > copy to selected to apply to rest selected object.


  • Parent: it will put under parent in hierarchy, keeping old location value (zero will align object to origin)
  • Parent keep transform: same as above
  • Parent without inverse: will parent, and zero its location.
  • Parent keep transform without inverse: (like Maya parent), location will recalculate with 0 at its parent. (zero location, will put object align with its parent)

Seperate object


Select edge loop

  • alt + RMB click
  • unlike Maya, material is stored in data, and show in the list of material choice for objects
  • there is no material grid view of all material created, but only from those dropdown list for object shader
  • in the Shader Editor panel, it only shows current select object's material, the whole panel is belong to current active object,
    • the Shader editor top dropdown UIs, it is active object material slots (how many material connected to this object) and material list in current file.
  • Note, blender can create material and if no object use them, they are considered as unuse blenddata (unused datablocks), when save file, they will be delete, so your material library wont store if not used in each file.
  • in Outliner, choce Blender File instead Scene in 2nd dropdown, you can see the tree of blend data structure, all materials currently there is under Material tree node.
  • in short, if you want keep your shader network builds, you need to assign them to something to hold reference to them
  • also, you can't reuse nodes directly cross different materials, you need to select nodes and create Node Group
    • Group nodes will be shown in shade edit Add menu>Group> yourGroupNode


  1. Many surfaces need to be “cut” to make it possible to unwrap them.
  2. The edges that will be cut “Seams”. In Edit Mode, selected edges can be marked or cleared as seams, using Mesh → Edges → Mark Seam (Ctrl E)
  3. UVs → LSCM Unwrap (E Key) in the UV editor will launch LSCM unwrapping

Techniques Section

Addon Plugins

Blender Automation

  • batch file to pass python_process_file and object_file to blender app
    @echo off
    rem Put the path of the blender folder and cd to the obj file folder
    set PATH=D:\blender-2.78a-windows64
    set FILENAME=Cliffs_Beach.blend
    set TARGET=Cliffs_Beach.obj
    blender %FILENAME% --background --python -- %TARGET%
  • the python process for file format convert in blender
    import bpy
    import sys
    argv = sys.argv
    argv = argv[argv.index("--") + 1:] # get all args after "--"
    obj_out = argv[0]
    bpy.ops.export_scene.obj(filepath=obj_out, axis_forward='-Z', axis_up='Y')

Blender Research

  • basically, use point density node in material setup to show the point density info as color
    • (first), go Render setting tab, change render from Eevee render to Cycle CPU render
    • use object vertex as info to fit the object per material, and assign that material to that object
    • radius is vertex search radius, which decide how the density amount calculated
    • resolution is actual dot render, 100 is 100×100 pixel render for each dot. dont need so high res sharp dots, as they will blend together

  • You can view material list in > Outliner [data api view]
  • You can check per object material usage case in > Outliner [scene view], expand the object arrow
    • You can also check per object material usage case in > Material tab panel (object selection required)
  • You can swith/edit object material in > Shader Editor (shift F3)
    • object selection required
    • if object is not assigned to any material, a New button is there instead
  • In viewport, you can view material on object as result of (Preview material view) or (render material view)
    • note, the (render material view) is linked to the > Render tab setting
    • some material like Point Density can only be used in Cycle CPU render setting, so make sure Render tab is set properly for the render material view to work
    • the default render preview is from Eevee GPU render.

  • appwiki/blender3d.txt
  • Last modified: 2023/09/13 10:20
  • by ying