/grid-map-raycasting

C++ component including Python bindings to raycast a gridmap from a viewpoint to check for occlusions

Primary LanguageC++

grid-map-raycasting

C++ component including Python bindings to raycast a gridmap from a viewpoint to check for occlusions

Prerequisites

On Unix (Linux, OS X)

  • A compiler with C++11 support
  • CMake >= 3.12
  • Ninja or Pip 10+

On Windows

  • Visual Studio 2015 or newer (required for all Python versions, see notes below)
  • CMake >= 3.12 (3.8 was the first version to support VS 2015) or Pip 10+

Installation

Please install the following C++ dependencies to use this repo:

conda install cmake pybind11 eigen

or alternatively on macOS with homebrew:

brew install cmake pybind11 eigen

or on Ubuntu with:

sudo apt install cmake python3-pybind11 libeigen3-dev

With the setup.py file included in this example, the pip install command will invoke CMake and build the pybind11 module as specified in CMakeLists.txt.

Usage

Please refer to the following sample code:

import grid_map_raycasting as m
import faulthandler; faulthandler.enable()
from matplotlib import pyplot as plt
import numpy as np

# Vantage point (e.g. robot position) is at x=0, y=0, z=1
vantage_point = np.array([0., 0., 1.], dtype=np.double)
# We define a flat Digital Elevation Map (DEM) at the ground-level
grid_map = np.zeros((64, 64), dtype=np.double)
grid_map[0:30, 0:10] = 3
# We define the resolution of the grid of the DEM in x and y direction
grid_resolution = np.array([1, 1], dtype=np.double)

# we perform ray-casting to receive the occlusion mask
occlusion_mask = m.rayCastGridMap(vantage_point, grid_map, grid_resolution)

# The occlusion mask we expect to receive as the output of the ray-casting
target_occlusion_mask = np.full((64, 64), False)
target_occlusion_mask[0:29, 0:9] = True

fig, axes = plt.subplots(nrows=1, ncols=2)
axes[0].set_title("Grid map")
axes[0].matshow(grid_map)
axes[1].set_title("Occlusion mask")
axes[1].matshow(occlusion_mask)
plt.show()

assert (occlusion_mask == target_occlusion_mask).all()

Special notes for Windows

Compiler requirements

Pybind11 requires a C++11 compliant compiler, i.e Visual Studio 2015 on Windows. This applies to all Python versions, including 2.7. Unlike regular C extension modules, it's perfectly fine to compile a pybind11 module with a VS version newer than the target Python's VS version. See the [FAQ] for more details.

Runtime requirements

The Visual C++ 2015 redistributable packages are a runtime requirement for this project. It can be found [here][vs2015_runtime]. If you use the Anaconda Python distribution, you can add vs2015_runtime as a platform-dependent runtime requirement for you package: see the conda.recipe/meta.yaml file in this example.