Motion Blur and Rolling Shutter

Motion blur readme image Rolling Shutter readme image

In this example we demonstrate how motion blur and a rolling shutter effect can be generated.

These effects are visible if either the camera or objects move between frames. The camera undergoes the following motion while the objects are stationary:

0 -10 4 1.3 0 0 # initial position
0 -15 4 1.3 0 0 # moving away from object
5 -15 4 1.3 0 0 # moving to the right
5 -15 8 1.3 0 0 # moving upwards
1 -11 5 1.3 0 0 # combined motion (to the left, towards object and downwards)

Usage

Execute in the BlenderProc main directory:

blenderproc run examples/advanced/motion_blur_rolling_shutter/main_motion_blur.py examples/advanced/motion_blur_rolling_shutter/camera_positions examples/resources/scene.obj examples/advanced/motion_blur_rolling_shutter/output

  • examples/advanced/motion_blur_rolling_shutter/main_{motion_blur / rolling_shutter}.py: path to the main python file to run.

  • examples/advanced/motion_blur_rolling_shutter/camera_positions: text file with parameters of camera positions.

  • examples/resources/scene.obj: path to the object file with the basic scene.

  • examples/advanced/motion_blur_rolling_shutter/output: path to the output directory.

The python script main_motion_blur.py creates pure motion blur, the python main_rolling_shutter.py a rolling shutter effect together with a small amount of motion blur.

Visualization

Visualize the generated data:

blenderproc vis hdf5 examples/advanced/motion_blur_rolling_shutter/output/0.hdf5

Implementation

Motion Blur

# Enable motion blur
bproc.renderer.enable_motion_blur(motion_blur_length=0.5)

  • motion_blur_length sets the time the shutter is open as fraction of the time between two frames. A value of 1 thus leaves the shutter open for the full time. The shutter opens half the motion_blur_length before the keyframe pose and closes half the time after.

Rolling Shutter

# Enable motion blur and rolling shutter
bproc.renderer.enable_motion_blur(
    motion_blur_length=0.8,
    rolling_shutter_type="TOP",
    rolling_shutter_length=0.05
)

  • rolling_shutter_length sets the time one scanline is exposed as fraction of the motion_blur_length. If this value is set to 1, no rolling shutter effect is created but just motion blur. If set to 0, a pure rolling shutter effect is achieved.