light_sampling

Light sampling

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

Usage

Execute in the BlenderProc main directory:

python run.py examples/light_sampling/config.yaml examples/light_sampling/camera_positions examples/light_sampling/scene.obj examples/light_sampling/output

• examples/light_sampling/config.yaml: path to the configuration file with pipeline configuration.
• examples/light_sampling/camera_positions: text file with parameters of camera positions.
• examples/light_sampling/scene.obj: path to the object file with the basic scene.
• examples/light_sampling/output: path to the output directory.

Visualization

Visualize the generated data:

python scripts/visHdf5Files.py examples/light_sampling/output/0.hdf5

Steps

• Loads scene.obj: loader.ObjectLoader module.
• Samples light position: light.LightSampler module.
• Loads camera positions from camera_positions: camera.CameraLoader module.
• Writes state of all objects to a file: writer.ObjectStateWriter module.
• Writes state of a light to a file: writer.LightStateWriter module.
• Writes state of camera poses tp a file: writer.CameraStateWriter module.
• Renders rgb: renderer.RgbRenderer module.
• Writes the output to .hdf5 containers: writer.Hdf5Writer module.

Config file

Light sampling

{
  "module": "lighting.LightSampler",
  "config": {
    "lights": [
      {
        "location": {
          "provider": "sampler.Shell",
          "center": [1, 2, 3],
          "radius_min": 4,
          "radius_max": 7,
          "elevation_min": 15,
          "elevation_max": 70
          },
          "type": "POINT",
          "energy": 500
      }
    ]
  }
},

The focus of this example is light.LightSampler module which allows one to sample values for various light attributes.

• Sample location in a spherical shell.

Note that for this we are using sampler.Shell Provider which is not a part of a module, but a useful tool for introducing some "controlled randomness" into the process. To call a sampler for some attribute of a camera, specify a name of a desired sampler and define some input arguments for it, e.g. center, radius_min, radius_max, etc. Sampler returns a value based on these input parameters specified in the config file, check the documentation for the samplers for more information on the input arguments, output formats, etc.

More examples

• semantic_segmentation: Introduction to semantic segmentation
• camera_sampling: More on sampling for cameras.
• entity_manipulation: More on the true power of Providers.