Preliminary Exploration On Visual Simulation Of Virtual Forest Environment

The dynamic changes of forest have two distinct characters, namely, the great spans both in temporal scale and spatial scale. It is this reason that leads forestry research in depth to confront more difficult situation. Introduced Virtual Forest Simulation, and combine with Computer Graphics and professional Forestry knowledge, complex forest dynamic models can be constructed and studied. Such way, with its advantages in large scale temporal and spatial spans, can provide modern forestry research with effective working platform, and has the study of comprehensive forest dynamic processes possible. Therefore, this direction has been focused on by many contemporaneous forestry scholars. The main work of this thesis for the purpose includes:·Monte Carlo simulation method was introduced, thereby a large amount of random numbers generated by computer were used to simulate forest growth states and statistical features of test data distribution, Based on the covariance function and correlation function, the statistical characters of data generated by computer, according to analysis of spatial relevance, were consistent with the simulated forest areas. Therefore, the simulated forest spatial data such as height,diameter at breast height,crown width could be obtained.·After the forest spatial data obtained, the regularity of stand growth was proposed according to forest self-thinning and growth competition relationship, then the method of simulating the time-varying property was brought forward which was performed by forecasting the forest development based on both the tree growth model and mortality rate. It can provide detailed and credible data source so that the dynamic growth processes of the virtual forest is able to be assessed.·Three improvements have been made in the visual interface technology as the following:1. Base on the tree architecture,the traditional geometric modeling technique is combined with tree's morphologic structure through tree architecture so that tree's interactive and parameterized modeling technique is introducted.2. Studied terrain generation and real-time rendering of lage-scale terrain scene,and introduced an improved redering method of multi-resolution terrain model based on GeoMipMapping method.3. Studied the special effect techniques to render sky ,sun light,fog and other objects to enhance the environment feeling of the virtual forest environments...