I am not able to render 2D images of 3D point cloud - rendering

Question

I am trying to render 2D images of point clouds from different viewpoints and save them as images.
I found a code online which does the same thing but for meshes. I tweaked it a little bit to import the 3D point cloud. But the code does not work and gives back black images. Please help me with this. I am open to use another library too if you know the solution. I just want to render the 2D images. Thank You
Code:
import os.path
import math
import sys
C = bpy.context
D = bpy.data
scene = D.scenes['Scene']
# cameras: a list of camera positions
# a camera position is defined by two parameters: (theta, phi),
# where we fix the "r" of (r, theta, phi) in spherical coordinate system.
# 5 orientations: front, right, back, left, top
cameras = [
(60, 0), (60, 90), (60, 180), (60, 270),
(0, 0)
]
# 12 orientations around the object with 30-deg elevation
# cameras = [(60, i) for i in range(0, 360, 30)]
render_setting = scene.render
# output image size = (W, H)
w = 500
h = 500
render_setting.resolution_x = w
render_setting.resolution_y = h
def main():
argv = sys.argv
argv = argv[argv.index('--') + 1:]
if len(argv) != 2:
print('phong.py args: <3d mesh path> <image dir>')
exit(-1)
model = argv[0]
image_dir = argv[1]
# blender has no native support for off files
# install_off_addon()
# init_camera()
fix_camera_to_origin()
do_model(model, image_dir)
def install_off_addon():
try:
# bpy.ops.preferences.addon_install(
# overwrite=False,
# filepath=os.path.dirname(__file__) +
# '/blender-off-addon/import_off.py'
# )
bpy.ops.preferences.addon_enable(module='import_off')
except Exception as e:
print(e)
print("""Import blender-off-addon failed.
Did you pull the blender-off-addon submodule?
$ git submodule update --recursive --remote
""")
exit(-1)
def init_camera():
cam = D.objects['Camera']
# select the camera object
scene.objects.active = cam
cam.select = True
# set the rendering mode to orthogonal and scale
C.object.data.type = 'ORTHO'
C.object.data.ortho_scale = 2.
def fix_camera_to_origin():
origin_name = 'Origin'
# create origin
try:
origin = D.objects[origin_name]
except KeyError:
bpy.ops.object.empty_add(type='SPHERE')
D.objects['Empty'].name = origin_name
origin = D.objects[origin_name]
origin.location = (0, 0, 0)
cam = D.objects['Camera']
# scene.objects.active = cam
# cam.select = True
if 'Track To' not in cam.constraints:
bpy.ops.object.constraint_add(type='TRACK_TO')
cam.constraints['Track To'].target = origin
cam.constraints['Track To'].track_axis = 'TRACK_NEGATIVE_Z'
cam.constraints['Track To'].up_axis = 'UP_Y'
def do_model(path, image_dir):
name = load_model(path)
center_model(name)
normalize_model(name)
image_subdir = os.path.join(image_dir, name)
for i, c in enumerate(cameras):
move_camera(c)
render()
save(image_subdir, '%s.%d' % (name, i))
# delete_model(name)
def load_model(path):
d = os.path.dirname(path)
ext = path.split('.')[-1]
name = os.path.basename(path).split('.')[0]
# handle weird object naming by Blender for stl files
if ext == 'stl':
name = name.title().replace('_', ' ')
if name not in D.objects:
print('loading :' + name)
if ext == 'stl':
bpy.ops.import_mesh.stl(filepath=path, directory=d,
filter_glob='*.stl')
elif ext == 'off':
bpy.ops.import_mesh.off(filepath=path, filter_glob='*.off')
elif ext == 'obj':
bpy.ops.import_scene.obj(filepath=path, filter_glob='*.obj')
else:
bpy.ops.import_mesh.ply(filepath=path, filter_glob='*.ply')
return name
def delete_model(name):
for ob in scene.objects:
if ob.type == 'MESH' and ob.name.startswith(name):
ob.select = True
else:
ob.select = False
bpy.ops.object.delete()
def center_model(name):
bpy.ops.object.origin_set(type='GEOMETRY_ORIGIN')
D.objects[name].location = (0, 0, 0)
def normalize_model(name):
obj = D.objects[name]
dim = obj.dimensions
print('original dim:' + str(dim))
if max(dim) > 0:
dim = dim / max(dim)
obj.dimensions = dim
print('new dim:' + str(dim))
def move_camera(coord):
def deg2rad(deg):
return deg * math.pi / 180.
r = 3.
theta, phi = deg2rad(coord[0]), deg2rad(coord[1])
loc_x = r * math.sin(theta) * math.cos(phi)
loc_y = r * math.sin(theta) * math.sin(phi)
loc_z = r * math.cos(theta)
D.objects['Camera'].location = (loc_x, loc_y, loc_z)
def render():
bpy.ops.render.render()
def save(image_dir, name):
path = os.path.join(image_dir, name + '.png')
D.images['Render Result'].save_render(filepath=path)
print('save to ' + path)
if __name__ == '__main__':
main()