Realistic and immersive 3D tree modeling is an important and challenging research topic in computer graphics

computer vision

and virtual reality.Furthermore

it is highly valuable in various applications such as virtual tourism

virtual city

virtual agriculture

ecological landscape

and so on.Many researchers in this field used various approaches of 3D tree modeling.However

a review work is not available on this topic

which has obviously blocked the development of image based modeling research.Different methods are classified and analyzed based on the visual clues used in modeling from a computer vision perspective.In this paper

all advanced 3D tree modeling technologies are surveyed

which are categorized as image-based

rule-based

and sketch-based methods.After analyzing and comparing several main 3D modeling methods and newly key modeling technologies

Such as approximate image-based tree-modeling using particle flows

single image tree modeling

sketch-based tree modeling using Markov random field

texture-lobes for tree modeling

image-based lightweight tree modeling

we draw several conclusions.Rule-based tree modeling is based on the assumption that the branch shapes and phyllotaxis of the tree follow a predictable pattern

but it is difficulty to reconstruct the unpredictable part of branches such as stunted growth or suffered external environment influence.Therefore people should master large professional knowledge of botany to reconstruct realistic rule-based tree model.When it comes to sketch-based tree modeling

the users usually stretch the outline from the tree images to obtain the seeds

which guide the growth of trees or morphological characteristics.Tree modeling is relatively simple and intuitive and even can be realized by automatic or semi-automatic way.Image-based tree modeling is a method that 3D space geometry information of the tree is built from two or more than two images.It can be built intelligently and the model is realistic.But the model data is too large to meet 3D visualization display of the large-scale virtual scene on the Internet.In addition

a research idea about hybrid lightweight tree modeling for lightweight

low cost

high efficiency

which is proposed according to the current research emphasis and difficulties.At last

the future of lightweight 3D tree modeling applied in the interactive virtual scene is presented.