Research On The Automatic Generation Technology Of3D Tree Modeling

The natural scenery is an important and indispensable part in3D games,commercial advertising, digital entertainment,city planning, applied research of thetree and virtual city, and the3D visual simulation of natural scenery has been a hotspot and difficulties in the field of virtual reality. As a kind of plant, trees have a widevariety of species, different shapes and complex structure, but also affected by manyfactors during growth process, so the modeling and visualization of the3DTree hasprodigious difficulty and challenge.This dissertation, in order to automatic generatehigh realistic3DTree modeling, conducted a in-depth study and exploration.This dissertation proposes a method based on fractal theory, combined with treesmorphological characteristics to realize3DTree visual simulation, by modifying a fewcontrol parameters it can generate different species of3DTree automated. Accordingto trees have the characteristics of fractal self-similar, combined with treesmorphological structure, abstract the organ models of the tree to describe each organ’sproperties and functions; In order to make more real3DTree establishing a basicelement model which consists of octagonal prism, based on the model using fractaliteration method can get the curve branches; Adopting random strategy, using randomcontrol function to improve the fractal iterative method, the generated3DTree aremore realistic; Using the method combined with Visual C++and OpenGL technologyto realize3DTree optimization modeling and visual simulation, get3DTree automaticgenerating system with strong universality and good human-computer interaction.To achieve more realistic3DTree model, we use the method combined withtexture mapping technology and BMP transparent handling technology to render theleaves, and using texture mapping method to render the branches and trunk;Considering the effects of light on the trees, we establish the light model to realize the3DTree visualization on different types of lights, at the same time we using shadowprojection algorithm to generate the shadow of the3DTree, the control parameters inthis algorithm are the position of the light position and the position of the ground. Inorder to quickly generate3DTree model without affecting the display effect of trees,we use the level of detail modeling techniques to automatically generate3DTreemodel, according to the distance between the viewpoint and the3DTree we choosedifferent levels of detail3DTree.On the basis of above research, we use the method combined with Visual C++and OpenGL technology to realize3DTree further optimization modeling and visualsimulation, and the automatic generated3DTree more efficient, rapid and accurate.