Results show that space exploration is well adapted to highlight architectural differences among trees. They also suggest that large-sized voxels are efficient for occlusion compensation at the expense of metrics precision in some cases. The best resolution to choose depending on the research objectives and quality of the TLS scan is discussed.

1. Visual information affects animal behaviour and fitness in diverse ways, but a lack of suitable methods to quantify visibility in three-dimensional (3D) environments limits applications of the concept of visibility in ecological research.2. The viewshed3d r package is dedicated to quantifying the visual environment from a single location or from a cumulation of viewpoints based on 3D point clouds acquired with terrestrial laser scanning. We present the entire workflow required to prepare the data and perform the visibility analyses in viewshed3d.3. This approach can help unlock the potential contributions of viewshed analyses to the emerging subdiscipline of 'viewshed ecology'. K E Y W O R D Sanimal behaviour, concealment, habitat structure, lidar data, predation risk, terrestrial laser scanner, viewshed, voxel How to cite this article: Lecigne B, Eitel JUH, Rachlow JL.viewshed3d: An r package for quantifying 3D visibility using terrestrial lidar data. Methods Ecol Evol. 2020;11:733-738.