Research On Plant Modeling Based On 3D Freehand Sketches And Photorealistic Processing

With the rapid development of virtual industry,plant modeling is playing an increasingly important role in game design,3D scene production and virtual reality.Among them,visual effect and modeling efficiency are the most concerned issues.However,the geometric diversity and complexity of plants and trees make modeling difficult.Therefore,how to simplify the method of plant modeling and ensure that the model results adapt to the needs of various industries is an important issue in plant modeling research.Based on the in-depth study of the existing plant modeling methods,this paper proposes a method of modeling plants directly in 3D space by drawing.This method is based on a special 3D space and completes the modeling task of complex structure plants by interactive hand drawing.The main research contents of this paper include the following four aspects:(1)We propose and design a virtual interactive 3D space rendering model method.Users can directly by the mouse on the 2D screen brush paint 3D plant model,the 3D space offers a variety of space transform method(multiple spindle rotation,translation,scaling,etc.),space supports different density under the requirements of space division,can store a large number of vertices and color information,support a user mapping through the shortcut key change space,real-time feedback on the drawing board 3D projection point and form a continuous 3 d images by matching algorithm,allows users to actively select,modify,delete any set of points in 3 d space,and unreasonable space problem may appear to provide a solution.(2)We propose and implement a method to draw complex structure plant model and an optimization algorithm.By recording the mouse track,automatic optimization schemes are provided for the unreasonable problems(including noise point,adhesion point and sparse point)that may occur in the drawing of images.The optimization schemes include de-dryness,extraction of feature points and curve fitting,etc.Themethod of continuous drawing in the real-time changing 3D space proposed in this paper has changed the traditional drawing method.Users can draw some line models with special structures and carry out combination expansion to simulate more complex plants(such as spiral vines).Is different from the 2D drawing board drawing,3D drawing needs not only plane coordinate space,and also need to provide drawing depth,ignoring the depth information will lead to problems such as model mismatch,imbalance,this paper optimized the pick up of system and depth matching method,realized the selection in 3D space by space,and based on the map to select the components associated drawing function of child widgets(for example,based on the principal branch do draw a limb).(3)We study and implement a real-time collision detection method for plant branches in virtual 3D space.Due to the 2D drawing of the screen Angle limit,when the user space mapping can't accurate perception in 3D space fully,prone to conflict model combinations,such as unreasonable model,collision,etc.,the same problem will happen in is used in the development model of fractal process and used to simulate the growth process of plant life cycle.This paper presents an optimized collision detection method.Gravity analysis algorithm,based on user input plant structure of the active learning,and the parent component extraction of effective information collection of relevant information,dynamic fractal rule,and in real time when a user triggers fractal command reasonable for fractal operation,in the solution to the problem of unreasonable drawing at the same time,to increase the speed and stability of the system.(4)Based on the above theories and methods,combined with DirectX graphics library,we used C++ language to complete the design and development of the prototype system.The system is based on a real-time variable space for 3D and 2D drawing board,through the optimization of user mouse input trajectory,expand,combined got the basic model,and based on the input model self-learning completed the basic model of the economy,with the introduction of collision detection model and the gravity balance model to achieve the realistic processing function,by providing rich parameter adjustment function and element collocation functionrealizes friendly user experience,and obtained good results,demonstrates the complete plant modeling in 3D space mapping directly the feasibility and superiority of this method.