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The focus of this example is the bproc.loader.load_shapenet(), which can be used to load objects from the ShapeNet dataset.

See the ShapeNet Webpage for downloading the data. We cannot provide the script for downloading the ShapeNet dataset because a user account on the ShapeNet webpage is needed.

Usage

Execute in the BlenderProc main directory:

blenderproc run examples/datasets/shapenet/main.py <PATH_TO_ShapeNetCore.v2> examples/datasets/shapenet/output

  • examples/datasets/shapenet/main.py: path to the python file with pipeline configuration.

  • <PATH_TO_ShapeNetCore.v2>: path to the downloaded shape net core v2 dataset, get it [here](http://www.shapenet.org/)

  • examples/datasets/shapenet/output: path to the output directory.

Visualization

In the output folder you will find a series of .hdf5 containers. These can be visualized with the script:

blenderproc vis hdf5 examples/datasets/shapenet/output/*.hdf5

Steps

  • Set the ShapeNet category as specified with bproc.loader.load_shapenet().

  • Sample camera poses bproc.camera.

  • Render RGB, Depth and Normal images bproc.renderer.

  • Collect the metadata of the ShapeNet object.

  • Collect Camera Pose and Instrinsics data.

  • Write HDF5 file: bproc.writer.write_hdf5().

Python file (main.py)

Global

bproc.init()

The same as in the basic example.

ShapeNetLoader

shapenet_obj = bproc.loader.load_shapenet(args.shapenet_path, used_synset_id="02691156", used_source_id="10155655850468db78d106ce0a280f87")

  • This loads a ShapeNet Object, it only needs the path to the ShapeNetCore.v2 folder, which is saved in args.shapenet_path.

  • The used_synset_id = 02691156 is set to the id of an airplane, and the used_source_id = 10155655850468db78d106ce0a280f87 selects one particular object of that category.

  • The position will be in the center of the scene.

  • By default, the object center will be moved to the bottom of the bounding box in Z direction and also in the middle of the X and Y plane which makes it easier to place them later on. This does not change the .location of the object. To disable this behaviour, set the move_object_origin flag to False.

CameraSampler

for i in range(5):
    # Sample random camera location around the object
    location = bproc.sampler.sphere([0, 0, 0], radius=2, mode="SURFACE")
    # Compute rotation based on vector going from location towards the location of the ShapeNet object
    rotation_matrix = bproc.camera.rotation_from_forward_vec(shapenet_obj.get_location() - location)
    # Add homog cam pose based on location an rotation
    cam2world_matrix = bproc.math.build_transformation_mat(location, rotation_matrix)
    bproc.camera.add_camera_pose(cam2world_matrix)

We sample here five random camera poses, where the location is on a sphere with a radius of 2 around the object. Each cameras rotation is such that it looks directly at the object and the camera faces upwards in Z direction.

RGB Renderer

# activate normal and depth rendering
bproc.renderer.enable_normals_output()
bproc.renderer.enable_depth_output(activate_antialiasing=False)

# render the whole pipeline
data = bproc.renderer.render()

To render with a transparent background, add bproc.renderer.set_output_format(enable_transparency=True). Depth and Normal images will also be produced.