Blender for cv

This library helps CV researchers to generate data using blender.

Library tutorial

This repo provides a simple package blcv that can put models into scene and get images from different viewpoints.

Install

You can use pip install blcv to install the package.

Note that we should use blcv in Blender's bundled Python, so you need to install the package in Blender's Python environment.

Use the following commands:

$ cd /blender-path/2.xx/python/bin/

/blender-path/2.xx/python/bin$ python.exe get-pip.py

/blender-path/2.xx/python/bin$ python.exe -m pip install blcv

If you encounter more problems installing blcv in Blender environment, you can refer to this answer.

If there is problems using pip, you can simply clone this repo, and use the files in blcv folder.

Functions

blcv

• call_blender(render_code, blender_executable_path, blank_blend_file_path, io_redirect='', background=True): activate Blender and call the script
  • render_code: directory to Blender script
  • blender_executable_path: directory to Blender.exe
  • blank_blend_file_path: Blender file
  • io_redirect: redirect the output into a file, use '' to show the output in command lines
  • background: whether run the Blender in background, default as 'True'

blcv.tools

• BcObject: operate an existed object in the scene
  • init(self, id): input the name of the object
  • destroy(self): delete the object
  • set_loc(self, x, y, z): set the object's location
  • get_loc(self, x, y, z): get the object's location
  • set_rot(self, x, y, z, w=None, mode='XYZ'): set the object's rotation; the mode includes 'AXIS_ANGLE', 'QUATERNION' and 'XYZ'
  • get_rot(self, mode='XYZ', w=None): set the object's rotation; the mode includes 'AXIS_ANGLE', 'QUATERNION' and 'XYZ'
  • set_scale(self, x, y, z): set the object's scale
  • get_scale(self, ): get the object's scale
• BcCamera(BcObject): operate an camera in the scene
  • init(self, id): input the name of the camera
  • set_camera_to_center(self, dist, azimuth_deg, elevation_deg, theta_deg): given the camera's rotation, set the camera in the position towards the center point [0, 0, 0]
• BcScene:
  • init(self)
  • set_render_mode(self, mode): set the background mode
  • get_img(self, filepath): save image crop in filaepath
• import_obj(shape_file): import a new model into the scene and return its name

Demo

You can modify the configurations and run start_blender.py to call blender_script in Blender.

The demo generates airplane images from circle viewpoints using the models in examples folder, the results will be saved in images folder.

Contact

If you have any questions or encounter any problems, feel free to contact me by sarahwei0210@gmail.com.