Blender 3D and python scripting - part 017.

In this tutorial I will show you how you can apply an modifier in Blender 3D using the python script.

First, you need to comment these source code rows in order to allow to apply the modifier.

## now set up shape key in Blender
#mesh=obj_branch.data
#sk_basis = obj_branch.shape_key_add(name='Basis',from_mix=False)
#sk_basis.interpolation = 'KEY_LINEAR'
## must set relative to false here
#obj_branch.data.shape_keys.use_relative = False

## create new shape key
#sk = obj_branch.shape_key_add(name='Deform',from_mix=False)
#sk.interpolation = 'KEY_LINEAR'
#sk.slider_min = 0
#sk.slider_max = 2

You cannot aply an modifier if you have skape keys.

To apply an modifyer you can use this line of source code:

# this will apply the modifier named 'SK'
bpy.ops.object.modifier_apply( modifier = 'SK' )

If you go to the UV Editing area you will see the modifier is apply and you can create an UV map.

Blender 3D and python scripting - part 016.

On this day, I will digress from the series of tutorials started and presented and show you how to install other python packages in Blender 3D.

Go to the bin folder where the python is install, see my path of Blender 3D.

C:\blender-3.3.0-alpha+master.add1da52ad78-windows.amd64-release\3.3\python\bin

Use these commands in to window command shell to install OpenCv python module.

python.exe -m ensurepip
python.exe -m pip install --upgrade pip
python.exe -m pip install opencv-python 
python.exe -m pip install opencv-contrib-python

Run in the blender script area these commands, in order to see if this python package working.

import cv2
cv2.version

You can create a simple script and test it, see the next example:

import numpy as np
import cv2
  
# Creating a black image with 3 channels
# RGB and unsigned int datatype
img = np.zeros((400, 400, 3), dtype = "uint8")
  
# Creating line
cv2.line(img, (21, 167), (100, 99), (0, 0, 255), 8)
  
cv2.imshow('dark', img)
  
# Allows us to see image
# until closed forcefully
cv2.waitKey(0)
cv2.destroyAllWindows()

You can see a screenshot with this python script:

Blender 3D and python scripting - part 015.

The tutorial for today is about adding armature to the skin, and has a single line of source code:

bpy.ops.object.skin_armature_create(modifier="SK")

This will add an armature with bones for each edge based on the skin modifier.

See the result of this ...

The full source code is this:

import bpy
import random

# import bmesh 
import bmesh

MinNubmer = -10
MaxNumber = 10

# Clean up the area , uncoment the next two row to keep
# branch after running the script
#bpy.ops.object.select_all(action="SELECT")
#bpy.ops.object.delete()

# Number of branches
branch = 4
# Create the verts array
verts = [(0,0,0)]
# Create the edges array
edges = [(0,0)]
# Create the faces array
faces = []

# define random number for X and Y axis 
def RN():
    return  random.randint(MinNubmer, MaxNumber) / 20 

# define random number for positive Z axis
def RNZ():
    return  random.randint(10, 50) / 10  

# create a list of branch thicknesses
rand_list = []

name_branch = "TreeMesh"
# define createBranch 

def createBranch(branch, name_branch):
    # Create the mesh for branch 
    mesh = bpy.data.meshes.new(name_branch) 
    for i in range(1,branch):
        rand_list.append(RNZ()/30)
        # sort all reverse by thicknesses
        rand_list.sort(reverse=True)

    # generate vertices list for drawing the branch
    for i in range(1,branch):
        verts.append((rand_list[i-1] +0.1,rand_list[i-1]+0.1,RNZ()))
        edges.append((i-1,i))

    # sort the list of vertices by last number witch is Z axis 
    verts.sort(key=lambda x: x[2])
    # create branch update and validate, see documentation
    mesh.from_pydata(verts, edges, faces) 
    mesh.update()
    mesh.validate()
    # Create object to hold the mesh branch with the new name for object
    obj = bpy.data.objects.new(name_branch+'_Obj', mesh)
    return obj

# create a new branch     
def createNewBranch(obj_branch, n):
    bpy.ops.object.mode_set(mode="EDIT", toggle=False)
    me = obj_branch.data
    bm = bmesh.from_edit_mesh(me)
    bm.select_mode = {'VERT'}

    for i,v in enumerate(bm.verts):
        # select only by the index of list 
        if i == n:
            v.select = ( v.co.x > 0.0 )
            v2 = v    
        else: 
            v.select = False
    # flush and update view 
    v1 = bm.verts.new( (RN()+(v.co.x) + 1.0 , RN()+(v.co.y) + 1.0 , (v.co.z) - (v.co.z)/3) )
    #v1 = bm.verts.new(1, 1, 3)
    bm.edges.new((v1, v2))
    rand_list.append(0.01)
    rand_list.sort(reverse=True)
    # update 
    bm.select_flush_mode()   
    me.update()
    #mesh.validate()
    #bmesh.update_edit_mesh(obj_branch.data)

# use the createBranch
obj_branch = createBranch(branch, name_branch)


# now set up shape key in Blender
mesh=obj_branch.data
sk_basis = obj_branch.shape_key_add(name='Basis',from_mix=False)
sk_basis.interpolation = 'KEY_LINEAR'
# must set relative to false here
obj_branch.data.shape_keys.use_relative = False

# create new shape key
sk = obj_branch.shape_key_add(name='Deform',from_mix=False)
sk.interpolation = 'KEY_LINEAR'
sk.slider_min = 0
sk.slider_max = 2

# ... and add it to the scene
scene = bpy.context.scene
scene.collection.objects.link(obj_branch)

# this will fix the error ...  mode_set_poll()
bpy.context.view_layer.objects.active = obj_branch  

createNewBranch(obj_branch, 1)

# print tool for developing area 
def print_python_console(data):
    for window in bpy.context.window_manager.windows:
        screen = window.screen
        for area in screen.areas:
            if area.type == 'CONSOLE':
                override = {'window': window, 'screen': screen, 'area': area}
                bpy.ops.console.scrollback_append(override, text=str(data), type="OUTPUT")

# used to see the size of radius skin for each vertices
print_python_console(rand_list)

# fix error :  skin modifier is locked when using edit mode.
bpy.ops.object.mode_set(mode="OBJECT", toggle=False)
# add the skin modifier
obj_branch.modifiers.new(name="SK", type="SKIN")
bpy.context.view_layer.objects.active = obj_branch  
# get the skin vertices layers
skin_vertices = obj_branch.data.skin_vertices
# get the layer
skin_layer = skin_vertices[0]
for i in range(1,branch+1):
    # assigns radius for each vertice to sized the branch 
    skin_layer.data[i-1].radius = (rand_list[i-1], rand_list[i-1]) 
    #Indices 0 and 1 are the vertex indices
    skin_layer.data[i].radius = (rand_list[i-1],rand_list[i-1])

bpy.ops.object.skin_armature_create(modifier="SK")

# set modes for user 
bpy.ops.object.mode_set(mode="EDIT", toggle=False)
bpy.ops.object.skin_root_mark()
bpy.ops.object.mode_set(mode="OBJECT", toggle=False)

Blender 3D and python scripting - part 014.

In this tutorial I will show you how can add a shape key to the branch using this source code:

# now set up shape key in Blender
mesh=obj_branch.data
sk_basis = obj_branch.shape_key_add(name='Basis',from_mix=False)
sk_basis.interpolation = 'KEY_LINEAR'
# must set relative to false here
obj_branch.data.shape_keys.use_relative = False

# create new shape key
sk = obj_branch.shape_key_add(name='Deform',from_mix=False)
sk.interpolation = 'KEY_LINEAR'
sk.slider_min = 0
sk.slider_max = 2

# ... and add it to the scene

Blender 3D and python scripting - part 013.

In today's tutorial I will present the source code with some minor fixes and an early way to fix the skin for the added branch.

Minor fixes are related to some errors in creating and passing data - I added comments.

It is interesting to see how I created and modified the source code step by step because it cannot be moved from one area to another because it is restrictive to the way it works in Blender 3D.

If I had used classes, this would not have been understood.

There are also minor technical details related to the skin, the random function for the thickness of the branches ...

For a source code written on the fly and without a pseudocode defined at the beginning I could say that the transitions between the source code between the tutorials is quite legible.

Here is a screenshot with some skin generated examples for the second branch for vertex position one.

This is the source basket used to create the new branch.

import bpy
import random

# import bmesh 
import bmesh

MinNubmer = -10
MaxNumber = 10

# Clean up the area , uncoment the next two row to keep
# branch after running the script
#bpy.ops.object.select_all(action="SELECT")
#bpy.ops.object.delete()

# Number of branches
branch = 4
# Create the verts array
verts = [(0,0,0)]
# Create the edges array
edges = [(0,0)]
# Create the faces array
faces = []

# define random number for X and Y axis 
def RN():
    return  random.randint(MinNubmer, MaxNumber) / 20 

# define random number for positive Z axis
def RNZ():
    return  random.randint(10, 50) / 10  

# create a list of branch thicknesses
rand_list = []

name_branch = "TreeMesh"
# define createBranch 

def createBranch(branch, name_branch):
    # Create the mesh for branch 
    mesh = bpy.data.meshes.new(name_branch) 
    for i in range(1,branch):
        rand_list.append(RNZ()/30)
        # sort all reverse by thicknesses
        rand_list.sort(reverse=True)

    # generate vertices list for drawing the branch
    for i in range(1,branch):
        verts.append((rand_list[i-1] +0.1,rand_list[i-1]+0.1,RNZ()))
        edges.append((i-1,i))
    
    # sort the list of vertices by last number witch is Z axis 
    verts.sort(key=lambda x: x[2])
    # create branch update and validate, see documentation
    mesh.from_pydata(verts, edges, faces) 
    mesh.update()
    mesh.validate()
    # Create object to hold the mesh branch with the new name for object
    obj = bpy.data.objects.new(name_branch+'_Obj', mesh)
    return obj

# create a new branch     
def createNewBranch(obj_branch, n):
    bpy.ops.object.mode_set(mode="EDIT", toggle=False)
    me = obj_branch.data
    bm = bmesh.from_edit_mesh(me)
    bm.select_mode = {'VERT'}

    for i,v in enumerate(bm.verts):
        # select only by the index of list 
        if i == n:
            v.select = ( v.co.x > 0.0 )
            v2 = v    
        else: 
            v.select = False
    # flush and update view 
    v1 = bm.verts.new( (RN()+(v.co.x) + 1.0 , RN()+(v.co.y) + 1.0 , (v.co.z) - (v.co.z)/3) )
    #v1 = bm.verts.new(1, 1, 3)
    bm.edges.new((v1, v2))
    rand_list.append(0.01)
    rand_list.sort(reverse=True)
    # update 
    bm.select_flush_mode()   
    me.update()
    #mesh.validate()
    #bmesh.update_edit_mesh(obj_branch.data)

# use the createBranch
obj_branch = createBranch(branch, name_branch)

# ... and add it to the scene
scene = bpy.context.scene
scene.collection.objects.link(obj_branch)

# this will fix the error ...  mode_set_poll()
bpy.context.view_layer.objects.active = obj_branch  

createNewBranch(obj_branch, 1)

# print tool for developing area 
def print_python_console(data):
    for window in bpy.context.window_manager.windows:
        screen = window.screen
        for area in screen.areas:
            if area.type == 'CONSOLE':
                override = {'window': window, 'screen': screen, 'area': area}
                bpy.ops.console.scrollback_append(override, text=str(data), type="OUTPUT")

# used to see the size of radius skin for each vertices
print_python_console(rand_list)

# fix error :  skin modifier is locked when using edit mode.
bpy.ops.object.mode_set(mode="OBJECT", toggle=False)
# add the skin modifier - NOT FIXED FOR THE LAST BRANC ADDED
obj_branch.modifiers.new(name="SK", type="SKIN")
bpy.context.view_layer.objects.active = obj_branch  
# get the skin vertices layers
skin_vertices = obj_branch.data.skin_vertices
# get the layer
skin_layer = skin_vertices[0]
for i in range(1,branch+1):
    # assigns radius for each vertice to sized the branch 
    skin_layer.data[i-1].radius = (rand_list[i-1], rand_list[i-1]) 
    #Indices 0 and 1 are the vertex indices
    skin_layer.data[i].radius = (rand_list[i-1],rand_list[i-1])

# set modes for user 
bpy.ops.object.mode_set(mode="EDIT", toggle=False)
bpy.ops.object.skin_root_mark()
bpy.ops.object.mode_set(mode="OBJECT", toggle=False)

Blender 3D and python scripting - part 012.

In this tutorial I will show you how you can add an extra branch to the existing one.

The source code was structured a bit with two createBranch and createNewBranch functions.

However, it is still in a raw structured format because such source code is aimed at using classes.

I did not solve the new branch size for the added vertex.

In the function that creates the new branch, the second parameter receives a number that represents the vertex from where the new edge will be created.

createNewBranch(obj_branch, 1)

In the source code we have the variable branch = 4, because the number of vertices starts in the list from 0 then argument 1 immediately means the next vertex from the first one in the list.

A random peak with close values ​​is generated and an edge is added to link it to the previously selected one.

Here is the source code that adds a new branch.

import bpy
import random

# import bmesh 
import bmesh

MinNubmer = -10
MaxNumber = 10

# Clean up the area , uncoment the next two row to keep
# branch after running the script
bpy.ops.object.select_all(action="SELECT")
bpy.ops.object.delete()

# Number of branches
branch = 4
# Create the verts array
verts = [(0,0,0)]
# Create the edges array
edges = [(0,0)]
# Create the faces array
faces = []

# define random number for X and Y axis 
def RN():
    return  random.randint(MinNubmer, MaxNumber) / 20 

# define random number for positive Z axis
def RNZ():
    return  random.randint(10, 50) / 10  

# create a list of branch thicknesses
rand_list = []

name_branch = "TreeMesh"
# define createBranch 
def createBranch(branch, name_branch):
    # Create the mesh for branch 
    mesh = bpy.data.meshes.new(name_branch) 
    for i in range(1,branch):
        rand_list.append(RNZ()/30)
        # sort all reverse by thicknesses
        rand_list.sort(reverse=True)

    # generate vertices list for drawing the branch
    for i in range(1,branch):
        rand_list.append(RN())
        verts.append((rand_list[i-1] +0.1,rand_list[i-1]+0.1,RNZ()))
        edges.append((i-1,i))
    
    # sort the list of vertices by last number witch is Z axis 
    verts.sort(key=lambda x: x[2])
    # create branch update and validate, see documentation
    mesh.from_pydata(verts, edges, faces) 
    mesh.update()
    mesh.validate()
    # Create object to hold the mesh branch with the new name for object
    obj = bpy.data.objects.new(name_branch+'_Obj', mesh)
    return obj

# use the createBranch
obj_branch = createBranch(branch, name_branch)

# ... and add it to the scene
scene = bpy.context.scene
scene.collection.objects.link(obj_branch)

# create a new branch     
def createNewBranch(obj_branch, n):
    bpy.ops.object.mode_set(mode="EDIT", toggle=False)
    me = obj_branch.data
    bm = bmesh.from_edit_mesh(me)
    bm.select_mode = {'VERT'}

    for i,v in enumerate(bm.verts):
        # select only by the index of list 
        if i == n:
            v.select = ( v.co.x > 0.0 )
            v2 = v    
        else: 
            v.select = False
    # flush and update view 
    v1 = bm.verts.new( (RN()+(v.co.x) + 0.1 , RN()+(v.co.y) + 0.1 , (v.co.z) - (v.co.z)/3) )
    #v1 = bm.verts.new(1, 1, 3)
    bm.edges.new((v1, v2))
    # update 
    bm.select_flush_mode()   
    me.update()
    #bmesh.update_edit_mesh(obj_branch.data)

# add the skin modifier - NOT FIXED FOR THE LAST BRANC ADDED
obj_branch.modifiers.new(name="SK", type="SKIN")
bpy.context.view_layer.objects.active = obj_branch  
# get the skin vertices layers
skin_vertices = obj_branch.data.skin_vertices
# get the layer
skin_layer = skin_vertices[0]

for i in range(0,branch):
    # assigns radius for each vertice to sized the branch 
    skin_layer.data[i-1].radius = (rand_list[i-1], rand_list[i-1]) 
    #Indices 0 and 1 are the vertex indices
    skin_layer.data[i].radius = (rand_list[i-1],rand_list[i-1])

# set modes for user 
bpy.ops.object.mode_set(mode="EDIT", toggle=False)
bpy.ops.object.skin_root_mark()

createNewBranch(obj_branch, 1)

bpy.ops.object.mode_set(mode="OBJECT", toggle=False)