Three-Dimensional Wheat Modelling Based on Leaf Morphological Features and Mesh Deformation

Chenxi Zheng,Wushuai Chang,Bo Chen,Weiliang Wen,Qiang Wu,Zhiwei Xiang,Chunjiang Zhao,Xianju Lu,Xinyu Guo

doi:10.3390/agronomy12020414

Abstract

The three-dimensional (3D) morphological structure of wheat directly reflects the interrelationship among genetics, environments, and cropping systems. However, the morphological complexity of wheat limits its rapid and accurate 3D modelling. We have developed a 3D wheat modelling method that is based on the progression from skeletons to mesh models. Firstly, we identified five morphological parameters that describe the 3D leaf features of wheat from amounts of 3D leaf digitizing data at the grain filling stage. The template samples were selected based on the similarity between the input leaf skeleton and leaf templates in the constructed wheat leaf database. The leaf modelling was then performed using the as-rigid-as-possible (ARAP) mesh deformation method. We found that 3D wheat modelling at the individual leaf level, leaf group, and individual plant scales can be achieved. Compared with directly acquiring 3D digitizing data for 3D modelling, it saves 79.9% of the time. The minimum correlation R2 of the extracted morphological leaf parameters between using the measured data and 3D model by this method was 0.91 and the maximum RMSE was 0.03, implying that this method preserves the morphological leaf features. The proposed method provides a strong foundation for further morphological phenotype extraction, functional–structural analysis, and virtual reality applications in wheat plants. Overall, we provide a new 3D modelling method for complex plants.

Highlights

Plant growth and development are predominantly reflected by the plants’ morphological structures and are significantly affected by several factors such as the type of cultivar, the growth period, and environmental parameters, as well as the cultivation and management measures
The numerical distribution of the morphological leaf parameters, including leaf size ratio, maximum leaf width position, leaf sag, leaf bending, and leaf twisting, were statistically analyzed at different leaf positions based on the obtained data from the 2775 wheat leaves (Figure 7)
The ordering results showed that the leaf sag increased in the clockwise direction, the leaf bending decreased in the clockwise direction, and the leaf twisting increased in the ordinate direction

Summary

Introduction

Plant growth and development are predominantly reflected by the plants’ morphological structures and are significantly affected by several factors such as the type of cultivar, the growth period, and environmental parameters, as well as the cultivation and management measures. The one-dimensional (1D) parameters such as plant height, plant coverage, leaf area index, leaf length, and leaf angle that are used to characterize the morphological and structural characteristics of plants present unique limitations. These parameters mostly describe the morphological structure of the plants, which does not reflect the three-dimensional (3D) morphological details of plant organs. The 3D modelling of plants has always been a challenging problem due to the complex morphological structure of plants and the stringent requirements of different applications for reconstruction accuracy and photorealism [5,6]

Methods

Results

Discussion

Conclusion