Description
Batch generate RGB-D format image pairs from *.obj models with textures in command line using Blender python script.
Quickstart
~$ python3 obj2rgbd.py
~$ python3 open3d_test.py
Requirements
- Blender 2.80 (need to test 2.82 - didn't work for some models)
- Python3: numpy, matplotlib, Pillow, OpenEXR, open3d (optional)
- Tested in Kubuntu 16.04
Setup
Blender
- Get Blender 2.80 (need to test 2.82 - didn't work for some models)
- Add Blender's path to your ~/.bashrc:
export PATH="/home/$USER/Downloads/blender-2.80-linux-glibc217-x86_64:$PATH"
Python 3
- numpy, matplotlib, pillow and open3d are trivially installed
- OpenEXR
pip install openexr
When it failed to install this link helped.
Details
obj2rgbd.py
~$ python3 obj2rgbd.py [input_folder [depth_map_resolution]]:
input_folder - folder with subfolders with *.obj files, default value - input
depth_map_resolution - units in the depth 16-bit *.png file, default value - 0.1, which is 10cm allowing for 0-6553.5 m range
| Value | Depth resolution | Depth range |
|---|---|---|
| 1 | 1 m | 0-65535 m |
| 0.1 | 10 cm | 0-6553.5 m |
| 0.01 | 1 cm | 0-655.35 m |
| 0.001 | 1 mm | 0-65.535 m |
What it does:
- Makes a list of all *.obj models found in a given input folder's subfolders
- Runs Blender feeding it with the blender_generate_image_and_depth.py and the list
- Blender script saves results into output/ (auto created). A single result is a rendered image of a model and the depth buffer saved into 32-bit float *.exr format
- After Blender is done for all models obj2rgbd.py then generates 16-bit *.png depth images with a given resolution from *.exr files. Results are also in the output/
Example:
- 10cm depth resolution
~$ python3 obj2rgbd.py input 0.1
open3d_test.py
~$ python3 open3d_test.py [path-to-image-file [path-to-depth-file]]:
path-to-image-file - jpeg, defaults to output/example-test_cube-image.jpeg
path-to-depth-file - 16-bit png, defaults to output/example-test_cube-depth-10cm.png
What is does:
- Opens RGB-D pair using Open3D python library. First it displays side-to-side, upon closing the first plot - it display a 3D view.
- Hardcoded parameters inside the script: w=2592, h=1902, fx=fy=2045, cx=1296, cy=951
Example:
~$ python3 open3d_test.py output/example-test_cube-image.jpeg output/example-test_cube-depth-10cm.png
blender_generate_image_and_depth.py
Can be run standalone:
~$ blender -b -P blender_generate_image_and_depth.py -- path1/model1.obj,path2/model2.obj
Notes
- Can have multiple models in the same subfolder
- Model names need to be unique as the output files are dumped in a single output/ folder
- *.obj filename must match with the name inside it. See example model in input/
- obj2rgbd.py running
blender -b -P blender_generate_image_and_depth.py -- filelist- Blender runs blender_generate_image_and_depth.py using its bundled python (Python 3.7 in Blender 2.80). Could have a single script for everything but it's too much effort to install openexr to that bundled python.
More models
https://community.elphel.com/3d+map
https://community.elphel.com/3d+biquad
Loading everything can take some time. Once loaded there's a download button in the top-right menu.