Blender 3D and python scripting - part 007.

In this tutorial I will show you how you create and use lights.

I used the same old source sode from the last tutorial.

Depending on the type of light created, their properties may change. Changing the on-fly light type cannot be done by a simple source code. Obviously you can recreate a new type of light with the new type you want.

This source code I added after this line of source code: scene = bpy.context.scene

# this create a light by type ['POINT', 'SUN', 'SPOT', 'HEMI', 'AREA']
light_data = bpy.data.lights.new('light', type='POINT')
# set light object 
light = bpy.data.objects.new('light', light_data)
# link light to collections
bpy.context.collection.objects.link(light)

light.location[0] = -1
light.location[1] = 3
light.location[2] = 3

light.data.color = (1.0, 0.0, 0.0)
light.data.energy=200.0
light.data.specular_factor = 0.5
# if you use another type like 'SUN' 
# then you can change properties like: angle 
#light.data.angle = pi * 10.0 / 180.0 

# get the name of the object light 
lamp = bpy.data.lights[light.name]

Blender 3D and python scripting - part 006.

In this tutorial I will show you how to use the camera and render an image.

I kept the source code from the old tutorial 005 and made the following changes:

I defined the global PI constant because I used it outside the definition.

import bpy

#define the pi global 
pi = 3.1415926

I added to the old source code the part of adding camera, translation, rotation, rendering settings and rendering an image called box_640_480.png in the 3D folder on the local disk.

You can see in the example below the added source code:

# define the new camera named NewCamera
camera_data = bpy.data.cameras.new(name='NewCamera')
# set camera_data to object 
camera_object = bpy.data.objects.new('ObjectCamera', camera_data)
# link camera object to scene
bpy.context.scene.collection.objects.link(camera_object)
# set active camera in the current scene by object
bpy.context.scene.camera = bpy.data.objects['ObjectCamera']
# set location 
camera_object.location = [0,-5,1]
# set rotation mode
camera_object.rotation_mode = 'XYZ'
# set the rotate the camerea using rotation_euler
bpy.data.objects[camera_object.name_full].rotation_euler = (90*(pi/180),0,0)

scene = bpy.context.scene

#these settings will set the render output
bpy.context.scene.cycles.samples = 1
scene.render.resolution_x = 640
scene.render.resolution_y = 480
scene.render.resolution_percentage = 100
scene.render.use_border = False
scene.render.image_settings.file_format='PNG'
scene.render.filepath='C:/3D/box_640_480.png'
bpy.ops.render.render(write_still=1)

Blender 3D and python scripting - part 005.

In this tutorial I will recreate the same box but with a more complex source code.

In the previous tutorial I used the same source code several times...

    obj = bpy.ops.mesh.primitive_plane_add(size=2, 
    calc_uvs=True, 
    enter_editmode=False, 
    align='CURSOR', 
    location=location, 
    rotation=(0, 0, 0), 
    scale=(0,0,0)
    )
    
    # rename the object
    bpy.context.object.name = obj_name
    # return the object reference
    return bpy.context.object

It is easier to understand the steps taken and then move on to optimizing them in complex forms.

Obviously a presentation of the source code in this tutorial will show you the differences.

I will add that the source code does not include scalar transformations and is limited to a box with size 1.

import bpy

def create_plane_XYZ(loc, obj_name):
    #define the pi 
    pi = 3.1415926
    # this is a definition like a tuple
    rot = (0,0,0)
    # need to convert it to a list in order to add new values
    rot_list = list(rot)
    # this ang variable will rotate obj to the 90-degree angle 
    ang = -90*(pi/180)
    ang_inc = 45*(pi/180)
    if loc[0] < 0:
        rot_list[1]=ang

    if loc[0] > 0: 
        rot_list[1]=ang

    if loc[1] < 0:
        rot_list[0]=ang
        
    if loc[1] > 0: 
        rot_list[0]=ang
    # this check if the two value from position of plane is not zero
    if loc[1] != loc[2] != 0: 
        rot_list[0]=ang_inc
    # this convert a list back to tuple 
    rot=tuple(rot_list)
    # this create the plane 
    obj = bpy.ops.mesh.primitive_plane_add(size=2, 
    calc_uvs=True, 
    enter_editmode=False, 
    align='CURSOR', 
    location=loc, 
    rotation= rot, 
    scale=(0,0,0)
    )
    # rename the object
    bpy.context.object.name = obj_name
    # return the object reference
    return bpy.context.object

# this will create a plane on X and translate with -1 on Y 
planeX001 = create_plane_XYZ((0,-1,0), "Plane-X")
# this will create a plane on X and translate with 1 on Y 
planeX002 = create_plane_XYZ((0,1,0), "Plane+X")
# this will create a plane on Y and translate with -1 on X 
planeY001 = create_plane_XYZ((-1,0,0), "Plane-Y")
# this will create a plane on X and translate with 1 on Y 
planeY002 = create_plane_XYZ((1,0,0), "Plane+Y")
# this will create a plane with 45 degree because two value on tuple is not zero
planeZ001 = create_plane_XYZ((0,-0.25,1.66), "Plane-Y+Z")

Blender 3D and python scripting - part 004.

In this tutorial, I will show you how to create a box from planes, see the screenshot:

You can see I used the math python package and I created rotation by radians and rotation object for three custom planes.

This is the source code:

import bpy

import math

def DegToRad(angle):
    """convert to radians"""
    return angle*(math.pi/180)


def RotOBJ(name, angles):
    """rotate obj to the specified angles"""
    rotation = [DegToRad(angle) for angle in angles]
    bpy.data.objects[name].rotation_euler = rotation
    
def create_plane_X(location, obj_name):

    obj = bpy.ops.mesh.primitive_plane_add(size=2, 
    calc_uvs=True, 
    enter_editmode=False, 
    align='CURSOR', 
    location=location, 
    rotation=(0, 0, 0), 
    scale=(0,0,0)
    )
    
    # rename the object
    bpy.context.object.name = obj_name
    # return the object reference
    return bpy.context.object

def create_plane_Y(location, obj_name):

    obj = bpy.ops.mesh.primitive_plane_add(size=2, 
    calc_uvs=True, 
    enter_editmode=False, 
    align='CURSOR', 
    location=location, 
    rotation=(0, 0, 0), 
    scale=(0,0,0)
    )
    
    # rename the object
    bpy.context.object.name = obj_name
    # return the object reference
    return bpy.context.object

def create_plane_Z(location, obj_name):

    obj = bpy.ops.mesh.primitive_plane_add(size=2, 
    calc_uvs=True, 
    enter_editmode=False, 
    align='CURSOR', 
    location=location, 
    rotation=(0, 0, 0), 
    scale=(0,0,0)
    )
    
    # rename the object
    bpy.context.object.name = obj_name
    # return the object reference
    return bpy.context.object

n = 1

planeX001 = create_plane_X((0,-1,0), "PlaneX-{:02d}".format(n))
RotOBJ(planeX001.name, [-90, 0, 0])
planeX002 = create_plane_X((0,1,0), "PlaneX-{:02d}".format(n))
RotOBJ(planeX002.name, [-90, -0, 0])

planeY001 = create_plane_Y((-1,0,0), "PlaneY-{:02d}".format(n))
RotOBJ(planeY001.name, [0, -90, 0])
planeY002 = create_plane_Y((1,0,0), "PlaneY-{:02d}".format(n))
RotOBJ(planeY002.name, [0, -90, 0])

planeZ001 = create_plane_Z((0,-0.25,1.66), "PlaneZ-{:02d}".format(n))
RotOBJ(planeZ001.name, [45, 0, 0])

Blender 3D and python scripting - part 003.

In the first tutorial I presented a simple script and in this one I improved it with a way to create lines with a number of points, to use pressurization and coloring according to these points.

I added comments in the source code to make it easier to understand.

Here is the result obtained for nineteen points:

This is the source code:

import bpy 
import random

#this is a for lines with N poins 
N = 19 

# this is default python script from the first tutorial
gpencil_data = bpy.data.grease_pencils.new("GPencil")
gpencil = bpy.data.objects.new(gpencil_data.name, gpencil_data)
bpy.context.collection.objects.link(gpencil)

gp_layer = gpencil_data.layers.new("lines")

gp_frame = gp_layer.frames.new(bpy.context.scene.frame_current)

gp_stroke = gp_frame.strokes.new()

gp_stroke.points.add(count=N)

# let's create a new material for pencil stroke 
gp_material_001 = bpy.data.materials.new(name="Grease pencil material 001")

# if you want to use Nodes 
gp_material_001.use_nodes = True

#this will add a diffuse color for this material 
gp_material_001.diffuse_color = (0.0, 0.0, 0.0, 1)

# create a new material for this grease pencil
bpy.data.materials.create_gpencil_data(gp_material_001)
# add the material to the grese pencil defined like gpencil 
gpencil.data.materials.append(gp_material_001)

for i in range (N):
    rand1 = random.randint(-3, 3)
    rand2 = random.randint(-3, 3)
    rand_size = random.randint(70, 76)
    gp_stroke.line_width = rand_size
    gp_stroke.points[i].co = (rand1,rand2,rand1)
    gp_stroke.points[i].co = (rand2,rand1,rand2)

    #this will create a random pressure 
    rand_pressure = random.randint(-3, 3) * 3
    #create random color for Red Green and Blue 
    rand_color_R = random.randint(0, 1)
    rand_color_G = random.randint(0, 1)
    rand_color_B = random.randint(0, 1)
    # set the pressure 
    gp_stroke.points[i].pressure = rand_pressure
    # set the color RGB with transparency 1
    gp_stroke.points[i].vertex_color = (rand_color_R,rand_color_G,rand_color_B, 1) 

Blender 3D and python scripting - part 002.

In today's tutorial I will show you how to create a sphere and how to add a material to it.

The source code is very simple with two functions one is for the sphere and the second one is the material of this, see:

import bpy

def create_sphere(radius, distance_to_center, obj_name):

    obj = bpy.ops.mesh.primitive_uv_sphere_add(
        radius=radius,
        location=(distance_to_center, 0, 0),
        scale=(1, 1, 1)
    )
    # rename the object
    bpy.context.object.name = obj_name
    # return the object reference
    return bpy.context.object


def create_emission_shader(color, strength, mat_name):
    # create a new material shader
    mat = bpy.data.materials.new(mat_name)
    # enable the node-graph edition mode
    mat.use_nodes = True
    
    # clear all starter nodes
    nodes = mat.node_tree.nodes
    nodes.clear()

    # add the Emission node
    node_emission = nodes.new(type="ShaderNodeEmission")
    # (input[0] is the color)
    node_emission.inputs[0].default_value = color
    # (input[1] is the strength)
    node_emission.inputs[1].default_value = strength
    
    # add the Output node
    node_output = nodes.new(type="ShaderNodeOutputMaterial")
    
    # link the two nodes
    links = mat.node_tree.links
    link = links.new(node_emission.outputs[0], node_output.inputs[0])

    # return the material reference
    return mat

n = 1
r = 1.0
d = 1.5

sphere001 = create_sphere(r, d, "Sphere-{:02d}".format(n))

sphere001.data.materials.append(
    create_emission_shader(
        (1, 1, 1, 1), 100, "SphereMat001"
    )
)

Blender 3D and python scripting - part 001.

Today I started a series of tutorials on python scripting and Blender 3D.

The first tutorial is how to draw using the Blender 3D features with the grease pencil utility using the Python scripting language.

Open Blender 3D in the scripting section and enter the source code below.

import bpy 
import random
rand1 = random.randint(-3, 3)
rand2 = random.randint(-3, 3)
rand_size = random.randint(70, 76)

gpencil_data = bpy.data.grease_pencils.new("GPencil")
gpencil = bpy.data.objects.new(gpencil_data.name, gpencil_data)
bpy.context.collection.objects.link(gpencil)

gp_layer = gpencil_data.layers.new("lines")

gp_frame = gp_layer.frames.new(bpy.context.scene.frame_current)

gp_stroke = gp_frame.strokes.new()
gp_stroke.line_width = rand_size

gp_stroke.points.add(count=4)

gp_stroke.points[0].co = (rand1,rand2,rand1)
gp_stroke.points[1].co = (rand2,rand1,rand2)

Run the script several times to see the effect produced.

Here is the result of running this script:

Blender 3D and Roblox with Python .

I spend my free time with my son playing Roblox and in the meantime, I try to introduce him to the world of computers.
However, you can download the player as a 3D object and use it as an avatar.
Here's an issue: The 3D object is hard to set with origins for animation but python and Blender 3D can easily solve this.
You can use BMesh.
As you know:
BMesh is the new Blender mesh system in 2.63, with full support for N-sided polygons instead of only triangles and quads.
The result of this download 3D object has a bad origin:

Let's see the source code:

import bpy
import bmesh
import mathutils 
from mathutils import Vector

context = bpy.context

def origin_to_bottom(obj):
    matrix_world = obj.matrix_world
    local_verts = [Vector(v[:]) for v in obj.bound_box]
    blender_mesh = blender_meshesh.new()
    blender_mesh.from_mesh(obj.data)
    x, y, z = 0, 0, 0
    l = len(local_verts)
    z = min([v.z for v in local_verts])
    local_origin = Vector((0, 0, 0))
    global_origin = matrix_world * local_origin
    for v in blender_mesh.verts:
        v.coord = v.coord - local_origin
    blender_mesh.to_mesh(obj.data)
    matrix_world.translation = global_origin

mesh_objs = [mesh_object for mesh_object in context.selected_objects if mesh_object.type == 'MESH']
bpy.ops.object.origin_set(type='ORIGIN_GEOMETRY')

for my_objects in mesh_objs:
    origin_to_bottom(my_objects)

The result is this:

Fix Gimp with python script.

Today I will show you how python language can help GIMP users.
From my point of view, Gimp does not properly import frames from GIF files.
This program imports GIF files in this way:

Using the python module, you can get the correct frames from the GIF file.
Here's my script that uses the python PIL module.

import sys
from PIL import Image, ImageSequence
try:
        img = Image.open(sys.argv[1])
except IOError:
        print "Cant load", infile
        sys.exit(1)

pal = img.getpalette()
prev = img.convert('RGBA')
prev_dispose = True
for i, frame in enumerate(ImageSequence.Iterator(img)):
    dispose = frame.dispose

    if frame.tile:
        x0, y0, x1, y1 = frame.tile[0][1]
        if not frame.palette.dirty:
            frame.putpalette(pal)
        frame = frame.crop((x0, y0, x1, y1))
        bbox = (x0, y0, x1, y1)
    else:
        bbox = None

    if dispose is None:
        prev.paste(frame, bbox, frame.convert('RGBA'))
        prev.save('result_%03d.png' % i)
        prev_dispose = False
    else:
        if prev_dispose:
            prev = Image.new('RGBA', img.size, (0, 0, 0, 0))
        out = prev.copy()
        out.paste(frame, bbox, frame.convert('RGBA'))
        out.save('result_%03d.png' % i)

Name the python script with convert_gif.py and then you can use it on the GIF file as follows:

C:\Python27>python.exe convert_gif.py 0001.gif

The final result has a smaller number of images than in Gimp, but this was to be expected.

Blender 3D - ellipsoid.

This is a simple way to use Blender 3D - version 2.78c with python scripting tool to make one ellipsoid.

The ellipsoid may be parameterized in several ways but I used the sin and cos functions:
x = sin(theta) * sin(phi)
y = cos(theta) * sin(phi)
z = cos(phi)
The steps I follow are:

• make points of ellipsoid - CoordsPoints
• define an ellipsoid vectors 
• create a new mesh 
• make rings for faces
• make an ellipsoid
• The verts_mesh and verts_mesh_face are used to make faces
• put all into the Blender 3D scene
  

import bpy
import bmesh
from math import degrees, radians, sin, cos, tan
from mathutils import Vector


class CoordsPoints:
    @property
    def xyz(self):
        theta = self.theta
        phi = self.phi
        x = sin(theta) * sin(phi)
        y = cos(theta) * sin(phi)
        z = cos(phi)
        R = self.R
        return R * Vector((x,y,z))

    def __init__(self, R, theta, phi):
        self.R = R
        self.theta = theta
        self.phi = phi
        #self.xyz = self.point(theta, phi)

    def __repr__(self):
        return "Coords(%.4f, %.4f)" % (degrees(self.theta),
                                               degrees(self.phi))
# define the ellipsoid method.
def ellipsoid(a, b, c):
    def ellipsoid(v):
        x = a * (v.x)
        y = b * (v.y)
        z = c * (v.z)
        return Vector((x, y, z))
    return ellipsoid

# make the ellipsoid bmesh
bm = bmesh.new()

# TODO come up with a nicer way to do this.
rings = [[CoordsPoints(1, radians(theta), radians(phi)) 
                 for theta in range (0, 360, 2)]
                 for phi in range(0, 180, 2)]

h = ellipsoid(1.0, 1.0, 1.5)

verts_mesh = [bm.verts.new(h(p.xyz)) for p in rings[0]]
verts_mesh.append(verts_mesh[0])
for ring in range(1, len(rings)):

    verts_mesh_face = [bm.verts.new(h(p.xyz)) for p in rings[ring]]
    verts_mesh_face.append(verts_mesh_face[0])

    faces = [
        bm.faces.new((
            verts_mesh[i], verts_mesh_face[i],
            verts_mesh_face[i+1], verts_mesh[i+1]
        ))
        for i in range(len(verts_mesh) - 1)
    ]
    verts_mesh = verts_mesh_face

# create mesh link it to scene 
mesh = bpy.data.meshes.new("ellipsoid")
bm.to_mesh(mesh)
obj = bpy.data.objects.new("ellipsoid", mesh)
scene = bpy.context.scene
scene.objects.link(obj)
scene.objects.active = obj
obj.select = True
obj.location = scene.cursor_location

Another simple effect with pygame.

The pygame module come with many features for users.
I used the pygame version to make one simple tutorial about pallete functions :
>>> print pygame.version.ver
1.9.2b1
The result of my tutorial is this: