Snowfall and Snowcover Models for Simulating Snowy Landscape

用于模拟雪景的降雪和积雪模型

• 批准号: 09680406
• 负责人: MURAOKA Kazunobu
• 金额: $ 2.37万
• 依托单位: IWATE UNIVERSITY (1999)Morioka Junior College,Iwate Prefectural University (1997-1998)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09680406/
• 关键词: computer grafhics; landscape simulation; physically-based modeling; natural phenomena; snowfall; snowcover; snowmelt; three-dimensional texture; 季節感

The landscape simulation using computer graphics (CG) is a powerful tool for the landscape assessment to city planning, development of sightseeing and so on. Because of this purpose, although the methods for expressing various seasons are desired to be developed, especially the development of the method for representing the severe winter is difficult.In this research, the following CG techniques for simulating snowy landscapes are developed.(1) The snow rendering methods: We developed two methods. One is the snowflake rendering method based on the three dimensional texturing, and other is the snow cover rendering method based on the volume rendering which uses 1/f noise for realizing the fluctuation of snowy density.(2) The snowfall simulation method: The snowfall simulation creates a field of air currents as a vortex field and trace the motion of snowflakes according to the forces given by the air current field and gravitation. The vortex field takes into account the interaction between vortices and obstacles.(3) Improvement of the snow cover simulation method: We improved the snow cover simulation method so as to be able to take an air current field into consideration. As a result, this method can generate the shape of the snow cover produced by the influences of an air current, such as snowdrift.(4) The snowmelt simulation method for defining shape of snow cover: This method enables us to simulate the transformation of the form of snow cover due to the radiant heat from the sun and objects, and the heat propagation in snow. Moreover, since the method considers the re-freeze of snowmelt, it can generate the icicle.(5) The method for modifying the shape of snow cover according to external forces : The method for representing a footprint or a rut left on a snow surface is developed. This method changes snow cover shape by taking into account kinetic energy of objects, e.g. feet or tires, and density of snow.

利用计算机图形学（CG）进行的景观模拟是城市规划、观光开发等景观评价的有力工具。由于这一目的，尽管需要开发各种季节的表示方法，但特别是严冬的表示方法的开发是困难的。在本研究中，开发了以下用于模拟雪景的CG技术。(1)雪渲染方法：我们开发了两种方法。一种是基于三维纹理的雪花绘制方法，另一种是基于体绘制的积雪绘制方法，该方法利用1/f噪声实现积雪密度的起伏。(2)降雪模拟方法：降雪模拟创建一个气流场作为涡流场，并根据气流场和重力给出的力跟踪雪花的运动。涡流场考虑了涡流和障碍物之间的相互作用。(3)积雪模拟方法的改进：我们改进了积雪模拟方法，以便能够考虑气流场。结果，该方法可以生成由气流的影响产生的积雪的形状，例如雪堆。(4)定义积雪形状的融雪模拟方法：该方法使我们能够模拟由于来自太阳和物体的辐射热以及雪中的热传播而导致的积雪形状的变化。此外，由于该方法考虑了融雪的再冻结，因此可以产生冰柱。(5)根据外力改变雪盖形状的方法：提出了表示雪地上留下的脚印或车辙的方法。该方法通过考虑物体（例如脚或轮胎）的动能和雪的密度来改变积雪形状。

项目成果

K.Muraoka: "Visual Simulation of Snowfall, Snowmelt and Snow Cover"Proceedings of ICPADS2000. (印刷中). (2000)

K. Muraoka：“降雪、融雪和积雪的视觉模拟”ICPADS2000 论文集（出版中）。

村岡一信: "異方性3次元テクスチャ法"画像電子学会誌. 28. 131-139 (1999)

Kazunobu Muraoka：“各向异性三维纹理方法”图像电子工程师学会杂志 28. 131-139 (1999)。

K.Muraoka: "A Visual Simulation of Melting Snow"The journal of the Institute of Image Electronics Engineers of Japan. Vol.27, No.4. 327-337 (1998)

K.Muraoka：“融化雪的视觉模拟”日本图像电子工程师学会期刊。

村岡一信: "融雪のビジュアルシミュレーション"画像電子学会誌. 27. 327-337 (1998)

Kazunobu Muraoka：“融雪的视觉模拟”图像电子工程师学会杂志 27. 327-337 (1998)。

K.Muraoka: "An Anisotropic Three-dimensional texture method"The journal of the Institute of Image Electronics Engineers of Japan. Vol.28, No.2. 131-139 (1999)

K.Muraoka：《一种各向异性三维纹理方法》日本图像电子工程师学会会刊。