A tool for visual analysis and photo-realistic rendering of forest landscape model simulations

Simulation outputs from Forest Landscape Models are complex, and tools for their visual analysis and effective communication are often limited. In this paper, we present EcoViz, a novel, open-source visualization platform designed to complement existing forest models by providing advanced 3D visualization capabilities. EcoViz facilitates the exploration of simulation results through two primary modes: symbolic rendering, designed for analytical tasks, such as pattern recognition and model evaluation, and photorealistic rendering, leveraging physically-based rendering (Mitsuba 3) and a custom library of European 3D tree models for communication purposes. The platform imports data in a typical model output format (e.g., spatially explicit individual tree or cohort data) and employs a temporally coherent sampling technique to visualize individual trees derived from cell-based density maps. Key features include: interactive side- by-side comparison of different simulation scenarios or time points, with synchronized navigation (viewpoint, timeline, transects), a mini-map overview, timeline controls with linked ecological metric graphs, and transect analysis tools. Developed using C++/Qt/OpenGL, EcoViz is cross-platform. The practical application of EcoViz is demonstrated by visualizing simulations of Berchtesgaden National Park under baseline and climate change scenarios exported from the iLand forest landscape model. This case study showcases the utility of EcoViz for comparative scenario analysis across spatial scales and how it aids model evaluation through visual inspection. While symbolic views support detailed analysis, the photorealistic output offers a compelling tool for science communication with diverse audiences, including scientific peers, forest managers, and the public.