Camera sampling

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In this example we are demonstrating the sampling features in relation to camera objects.

Usage

Execute in the BlenderProc main directory:

blenderproc run examples/basics/camera_sampling/main.py examples/resources/scene.obj examples/basics/camera_sampling/output

examples/basics/camera_sampling/main.py: path to the python file.
examples/resources/scene.obj: path to the object file with the basic scene.
examples/basics/camera_sampling/output: path to the output directory.

Visualization

Visualize the generated data:

blenderproc vis hdf5 examples/basics/camera_sampling/output/0.hdf5

Steps

Camera sampling

# Find point of interest, all cam poses should look towards it
poi = bproc.object.compute_poi(objs)
# Sample five camera poses
for i in range(5):
    # Sample random camera location above objects
    location = np.random.uniform([-10, -10, 8], [10, 10, 12])
    # Compute rotation based on vector going from location towards poi
    rotation_matrix = bproc.camera.rotation_from_forward_vec(poi - location, inplane_rot=np.random.uniform(-0.7854, 0.7854))
    # 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)

In this example, all camera poses are constrained to “look at” a point of interest (POI).

Sample location uniformly in a bounding box above the plane.
Set orientation of the camera such that it will always look at the POI at any given location. By using the bproc.camera.rotation_from_forward_vec fct.
Optionally, add an "inplane_rot" value to rotate the camera around the optical axis. All values are in radians not in degree.