Synthetic-Data-Generation in Blender

randomize_camera_loc.py

import bpy
from numpy.random import uniform

def rand_camera_loc(camera, xloc_range, yloc_range, zloc_range):
    """ Randomize camera location for each axis based on the provided ranges """
    new_loc = camera.location
    new_loc[0] = uniform(low=xloc_range[0], high=xloc_range[1])
    new_loc[1] = uniform(low=yloc_range[0], high=yloc_range[1])
    new_loc[2] = uniform(low=zloc_range[0], high=zloc_range[1])
    camera.location = new_loc
    
camera = bpy.data.objects['Camera'] # target camera to use
rand_camera_loc(camera, [-1,1], [-1,1], [-0.5,0.5])

randomize_materials.py

import bpy  # Blender specific import
import numpy as np
from datetime import datetime

def randomize_colors(material, color_nodes_names):
    """ Randomize RGB nodes for the given Blender material """
    # apply colors in target material
    # naive way to generate multiple colors (as there is no guarantee of enough difference)
    for i, color_nodes_name in enumerate(color_nodes_names):
        rand_rgb = np.random.uniform(low=0., high=1., size=3)
        rand_rgb = np.append(rand_rgb, 1.)
        material.node_tree.nodes[color_nodes_name].outputs[0].default_value = tuple(rand_rgb)


def randomize_plain_pattern():
    material = bpy.data.materials["plain"]
    randomize_colors(material, ["RGB"])


def randomize_striped_pattern():
    material = bpy.data.materials["striped"]
    wave_texture = material.node_tree.nodes["Wave Texture"]
    wave_texture.inputs[1].default_value = np.random.uniform(low=2, high=12)  # rand scale
    wave_texture.bands_direction = np.random.choice(['Y', 'X'])  # rand bands direction
    
    randomize_colors(material, ["RGB", "RGB.001"])
    
def randomize_floral_pattern(texture_img_paths):
    material = bpy.data.materials["floral"]

    # load random texture image
    image = bpy.data.images.load(filepath=str(np.random.choice(texture_img_paths)))
    material.node_tree.nodes["Image Texture"].image = image

    # rand texture scale
    rand_scale = np.random.uniform(low=1.5, high=8)
    material.node_tree.nodes["Mapping"].inputs[3].default_value[0] = rand_scale
    material.node_tree.nodes["Mapping"].inputs[3].default_value[1] = rand_scale
    material.node_tree.nodes["Mapping"].inputs[3].default_value[2] = rand_scale

    randomize_colors(material, ["RGB"])
    
randomize_plain_pattern()
randomize_striped_pattern()
randomize_floral_pattern(['list', 'of', 'floral', 'image-paths'])

randomize_world.py

import bpy
import numpy as np
from numpy.random import uniform

def randomize_world(bg_strength_range):
    """ Randomize World settings """
    world = bpy.data.worlds["World"].node_tree
    
    # random world color value
    world_rgba = uniform(low=0, high=1, size=3)
    world_rgba = np.append(world_rgba, 1.)
    world.nodes["RGB"].outputs[0].default_value = world_rgba

    # random world background strength
    rand_bg = uniform(low=bg_strength_range[0], high=bg_strength_range[1])
    world.nodes["Background"].inputs[1].default_value = rand_bg
    
randomize_world(bg_strength_range=[0.2, 0.4])

render_still.py

import bpy
from datetime import datetime

def render_still(filepath: str, file_format='PNG'):
    """ Render a still frame for the current Blender scene """
    bpy.context.scene.render.filepath = filepath
    bpy.context.scene.render.image_settings.file_format = file_format
    bpy.ops.render.render(write_still=True)

render_still(f"{datetime.now().strftime('%Y%m%d_%H%M')}.png"))