1.Necessity of experiment construction

①The particularity and irreversibility of on-site construction of landscape architecture design The final design of the landscape architecture design course is drawings, and the ultimate goal of landscape architecture design is to complete the on-site construction of drawings. In fact, the site is relatively scarce, the materials are expensive, the transportation cost and the installation cost are high, the teaching site resources cannot be reused, and the construction process is not fault-tolerant and irreversible. Therefore, using virtual simulation technology, the construction of landscape architecture design can be carried out, which effectively ensures the continuity of landscape architecture design and construction practice teaching.

②The complexity of low-impact development green space design As an important type of landscape architecture design, low-impact development green space is the frontier field of landscape design in recent years. The design and construction process of low-impact green space development is relatively complicated and hard to be taught, especially when it is difficult to control the precipitation process in the actual environment. Using the virtual simulation technology can simulate with different intensities of precipitation in the performance of low-impact development green space , and optimize the design through the simulation results.

③Lack of scientific quantitative system for landscape architecture design Since traditional landscape architecture design evaluation is mostly based on subjective artistic perception, it lacks an evaluation system that quantifies the ecological benefits of the site. The experiment applies advanced evidence-based theory and introduces a landscape performance evaluation system centered on evidence-based concepts into the virtual simulation platform. It is an important way to upgrade traditional technology to modern landscape design technology. In line with internationally recognized LEED, SITES, LPS and other standards, the experiment ensure the forward-looking and scientific nature of the quantitative system.

2.Teaching demand-oriented guidingness

Landscape design is developing rapidly. The new era landscape design needs to emphasize the close combination of design and practice on the basis of inheriting garden art and design methods. By building a low-impact development green space evidence-based design and a virtual simulation experimental system platform, it will meet the needs of actual construction after the design is completed in order to verify the design effect. The experiment enables students to carry out actual construction training in the virtual space and improve the effect of experimental teaching. The experimental teaching project system development is advanced in the following three aspects.

① The industry‘s frontier fields as the virtual simulation experiment object. In the selection of experimental subjects, a virtual scene is constructed based on the low-impact development green space (corridor and rain garden) of a campus in Beijing with 3D modeling, animation and other technical to simulate the wooden and steel corridor frames and a variety of plant options. It highlights the teaching goals which take low-impact development green space evidence-based design and construction of the industry’s frontier as the center.

②The experiment construction process is interactive and close to teaching practice. The design process of the experimental construction strives to be concise and clear with good interactive effects. Through the keyboard and mouseusers can choose the material of the corridor frame, the construction method, and the water storage mode of the rainwater garden in the virtual scene, guiding students to correctly understand the construction process of the corridor and rainwater garden, allowing students to experience the interaction as if they were in the real situation.

③The experimental evaluation results are more realistic and scientific. The student work in the virtual space is evaluated by the landscape performance evaluation system, which can automatically calculate many ecological and economic benefits, so that students and teachers can get feedback on the design results in real time and complete the evidence-based design process.

3.Features and advantages of experimental teaching

① Flexible teaching methods In the experimental process of immersive experience, interactive exercises, independent design and evidence-based evaluation, students can master the methods of landscape site paving and rainwater gardens to gain basic awareness of evidence-based design. The experiment breaks the limitations of fixed places, extends traditional textbook teaching as well as field teaching and fixes class time into online classrooms. Through the three-dimensional virtual simulation model with lifelike image, it can achieves free and flexible interactive operation.

② Obvious teaching effect The experiment improves students‘ professional interest and ability to integrate theory with practice. The system platform uses three-dimensional simulation technology to reproduce the construction of corridors, sites, rainwater gardens, storm flood simulation, and landscape performance evaluation. From raw material processing to pretreatment, plot selection to structure construction and finally to the individual formation, multiple parameters are controlled in the process to achieve a wide coverage of the construction process and results to achieve the effect of reproducing the entire construction process. The experiment helps to deepen students’ awareness of the complex structure, principle and working process of corridors and rainwater garden construction projects to experience the immersion of immersive and autonomous construction in virtual simulation experiments.

③ Innovation of feedback evaluation system The evaluation system covers two parts: self-feedback evaluation and teacher evaluation. During the learning process, students can understand the impact of different materials and construction methods on the results of landscape architecture through system feedback at any time in order to continuously optimize the design plan and enhance the scientific nature of the design results. Teachers grade the online exercises and evaluate every aspect of the students' garden construction through electronic answers to quickly obtain students' teaching feedback results.

4.Extension and expansion of traditional teaching

① Extend the depth and breadth of the experiment content Using virtual simulation technology, students can establish a complete and correct consciousness in real time from the initial awareness of space to future planning and design to cultivate certain constructive thinking skills. The actual construction experience can be got in the virtual operation to enhance students‘ cognition and control ability of multi-scale as well as multi-type garden space construction. Incorporating the ecological and economic benefits of the site into the scope of construction cognition, integrating the evidence-based process into the construction teaching of design can improve students' ability to analyze design results.

② Improve teaching efficiency Using the interactive function of virtual simulation, students can experience the construction of landscape architecture at any time and quickly, comprehensively understand the impact of different materials and construction methods on the results of landscape architecture. The new experimental teaching mode that combines online and offline teaching effectively improves teaching efficiency on the basis of traditional teaching.