Modeling and Optimization of a Tree Based on Virtual Reality for Immersive Virtual Landscape Generation

Abstract

This study proposes a modeling method that can effectively generate multiple diverse digital trees for creating immersive virtual landscape based on virtual reality and an optimization method for real-time rendering. The proposed method simplifies a process of procedures from growth of tree models to the generation of the three-dimensional branch geometric model. Here, the procedural branch graph (PBG) algorithm is proposed, which simultaneously and effectively generates diverse trees that have a similar branch pattern. Moreover, the optimization method is designed in a polygon-based branch model which controls the resolution of tree models according to the distance from the camera to generate a tree model structure that is appropriate for an immersive system based on virtual reality. Finally, a virtual reality system is established based on the Oculus SDK (Software Development Kit) and Unity3D engine. In this process, the image processing-based pixel to tree (PTT) method is proposed as a technique for easily and efficiently generating a virtual landscape by allocating multiple trees on terrain. An immersive virtual landscape that has a stereoscopic perception and spatial impression is created through the proposed method and whether it can deliver experience of nature in virtual reality to the users was checked through an experiment.

Feasibility and user experience of virtual reality fashion stores

“…A large number of polygons is problematic as it requires a large amount of processing which slows down the VR system significantly (Marks et al 2014). A VR model with more polygons reduces the rendering speed of the system, causing delayed display of the scene following the user's head movement (Kim 2016). This affects a VR system's ability to provide immersive experiences, and is known to induce simulator sickness (Kim 2016).…”

“…A VR model with more polygons reduces the rendering speed of the system, causing delayed display of the scene following the user's head movement (Kim 2016). This affects a VR system's ability to provide immersive experiences, and is known to induce simulator sickness (Kim 2016). To prevent this problem, model optimization tools [e.g., Level of Detail (LOD)] that reduce the number of polygons rendered for an object (Yilmaz et al 2004) are used.…”

MAVE: Maze‐based immersive virtual environment for new presence and experience

“…Dylla et al used procedural modeling to study the reconstruction of Rome as a virtual city. Kim also studied ways of effectively expressing VR‐based landscape by automatically generating diverse trees through procedural modeling. Most such research, however, considers real‐time systems, like games, as their application boundaries and does not account for the technical factors (refresh rate, fps, etc.)…”

“…Nevertheless, research on creating complex virtual spaces is essential because VR technology is applied to many areas, ranging from fine arts to architectural design. To this end, there are studies on the automatic creation of unique virtual scenes that are complex in structure, including urban spaces or virtual landscapes in procedural structures …”

A Survey on the Procedural Generation of Virtual Worlds

“…When we take a look at the practical application of methods for tree and plant generation, one can see that the most commonly used tools Xfrog [64] or Speedtree [65] reach impressive results. In [66], the authors propose a procedural branch graph (PBG) approach that creates diverse trees with the same branch structure at different LODs (Level of Detail). Further state-of-the-art research such as [58,67,68] confirms the high maturity level of this research area.…”