Render and synthesize objects from front, back, left and right
To fill in the blanks in Blender Advent Calendar 2020 I will write an article about the 2.8 compatible version of the previously published script
Render the selected object from front, back, left and right,
It is a script that synthesizes into one image,
Adjust the camera settings so that the shape selected in the 3D view fits
Create an image rendered with front-back, left-right parallel projection and the current camera settings, and create a side-by-side image with the name [Combineed_IMG].
Please note that an error will occur if you do not select a mesh object.
render_around.py
import bpy
import math
import os
import numpy as np
import mathutils
#Fixed render width
render_width = 300
#Rendered image storage path
render_path = bpy.context.scene.render.filepath
def render_func(context):
#Camera used in the scene
camera = context.scene.camera
if len(context.selected_objects) == 0: return
###############################
###########Save settings###########
##Rendering size
render = context.scene.render
ref_render_x = render.resolution_x
ref_render_y = render.resolution_y
ref_render_percentage =render.resolution_percentage
##Camera type (perspective projection,Parallel projection, etc.)
ref_camera_type = camera.data.type
##position
ref_location = camera.location.copy()
ref_rotate = camera.rotation_euler.copy()
##################################
##In object mode
bpy.ops.object.mode_set(mode = 'OBJECT')
#bpy.ops.object.select_all(action="DESELECT")
##################################
##Camera settings
###Rendering size
(bbox_width, center_pos) = get_bound_data(context)
set_render_size(context, bbox_width)
#Rendered in the initial state
bpy.ops.render.render()
#Save
f_name = "view4.png "
seve_render(f_name)
###Parallel projection
camera.data.type = 'ORTHO'
#Set the scale of parallel projection (width is based on BU)
camera.data.ortho_scale = max(bbox_width)*1.2
#Camera position(0, -10, 0.3)Rotate(90°, 0, 0)To
camera_pos =get_camera_pos_top(bbox_width, center_pos)
camera.location = camera_pos
camera.rotation_euler = (math.radians(90.0), 0, 0)
#########################################
pos = mathutils.Vector((camera_pos))
mat_rot1 = mathutils.Matrix.Rotation(math.radians(90.0), 4, 'Z')
mat_trs = mathutils.Matrix.Translation(mathutils.Vector(center_pos))
mat_rot = mat_trs *mat_rot1 *mat_trs.inverted()
for i in range(4):
#rendering
bpy.ops.render.render()
#Save
f_name = "view%s.png " % i
seve_render(f_name)
#90 degree rotation
pos = mat_rot @ pos
camera.location = pos
cam_rot = (math.radians(90.0), 0, math.radians(90.0)*(i+1))
camera.rotation_euler = cam_rot
##################################
###########Write back settings###########
###Rendering size
render.resolution_x = ref_render_x
render.resolution_y = ref_render_y
render.resolution_percentage = ref_render_percentage
##Camera type
camera.data.type = ref_camera_type
##position
camera.location = ref_location
camera.rotation_euler = ref_rotate
#########################################
combine_image(render_path)
#Get drawing range data from the selected shape (center point),width)
def get_bound_data(context):
objects = context.selected_objects
bb_point_list = []
#Get the bbox value of the selected shape in global coordinates
for obj in objects:
if obj.type != 'MESH':continue
bbox_list = [mathutils.Vector(v[:]) for v in obj.bound_box]
mat = obj.matrix_world
bb_point_list += [mat@v for v in bbox_list]
#Get range
bbox_width = []
center_pos = []
for i in range(3):
min_i = min(bb_point_list, key = (lambda x: x[i]))[i]
max_i = max(bb_point_list, key = (lambda x: x[i]))[i]
bbox_width.append( max_i - min_i )
center_pos.append( (max_i + min_i)/2 )
return(bbox_width, center_pos)
#Render size setting (fixed width)
def set_render_size(context, bbox_width):
render = context.scene.render
#print(bbox_width)
#Get vertical length
render_height = int(render_width*(bbox_width[2]/max(bbox_width[:2])))
if render_height < render_width: render_height = render_width
render.resolution_x = render_width
render.resolution_y = render_height
render.resolution_percentage = 100
#Set camera position for front image rendering
def get_camera_pos_top(bbox_width, center_pos):
distance = max(bbox_width)
return(center_pos[0], center_pos[1]-distance,center_pos[2])
#Save image
def seve_render(f_name):
img_path = os.path.join(render_path,f_name)
bpy.data.images['Render Result'].save_render(filepath=img_path)
#Loading images
def load_tex(f_path):
img = bpy.data.images.load(f_path)
return(img)
#Convert rgba image to nparray
def img_to_nparray(img):
bit_len = len(img.pixels)
(width,height) = img.size
channels = img.channels #Number of colors
#Create numpy array
pixlist = np.array(img.pixels)
pixlist = pixlist.reshape( height, width, 4)
return( pixlist )
#Join process
def combine_image(render_path):
width = 0
height = 0
image_list = []
for i in range(5):
f_name = "view%s.png " % i
img_path = os.path.join(render_path,f_name)
img = load_tex(img_path)
image_list.append(img)
width += img.size[0]
height = max(height, img.size[1])
combine_img_np = np.zeros((height, width, 4))
offset = 0
for img in image_list:
#Convert the read image into a numpy array
np_array = img_to_nparray(img)
(height, width, deps) = np_array.shape
#Join process
combine_img_np[0:height, offset:offset + width] = np_array
combine_img_np[:,offset] = np.ones(4)
offset += width
#Create a Blender image data object from a numpy array
img_name = 'Combineed_IMG'
(height, width, deps) = combine_img_np.shape
image_object = bpy.data.images.new(name=img_name, width=width, height=height)
image_object.pixels = list(combine_img_np.flatten())
for img in image_list:
bpy.data.images.remove(img)
render_func(bpy.context)
The previous version is compatible with 2.8 or later and has some bug fixes.