Masanori Kakimoto

Real-time rendering of physically based optical effects in theory and practice

classroom use is granted without fee provided that copies are not made or distributed for commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for third-party components of this work must be honored. For all other uses, contact the Owner/Author. Copyright is held by the owner/author(s). SIGGRAPH 2015 Courses, August 09 – 13, 2015, Los Angeles, CA. ACM 978-1-4503-3634-5/15/08. Real-time Rendering of Physically Based Optical Effects in Theory and Practice

Reproduction of the behavior of the wet cloths taking the atmospheric pressure into account

The property of cloth changes when it gets wet. Especially, wet cloth sticks to objects being touched. When expressing a wet cloth in computer graphics, pseudo representation is often used. As existing research, [Gascon et al. 2010] added a constrain to the part of cloth where it touches the base object. This constraint is a force which makes the cloth continue sticking to the position while the cloth is touching. In real-world situations, however, such sticking forces act even on the part which stays off the base.

Visual simulation of glazed frost

Glazed frost is a crystal clear ice and formed from supercooled raindrops that freeze when they hit object surfaces such as the ground and branches of trees. Simulation methods for formation of ice crystal, such as frost, on the surface of objects have been proposed by Kim et al. [Kim et al. 2004]. However, a supercooling state has to be considered for simulating freezing rain, and fluid simulation is required for reproducing the effect of raindrops running down on the ice surfaces. To our best knowledge, there has been no research presenting glazed frost by using a fluid simulation. We use the fluid simulation based on FLIP method [Zhu and Bridson 2005]. Hence, raindrops and obstacles are represented by particles which are used to calculate the advection term, and the update of velocity field are calculated by using grids except for advection term. We propose a method to create an animation of glazed frost formation by taking into account the heat transfer between particles and the outside grids.

Rusting and corroding simulation taking into account chemical reaction processes

In recent years, expressions close to realities have become possible thanks to the technologically advanced computer graphics. Secular change and weathering are important factors to create realistic computer graphics images. Metal rust is an important secular change and there are much research work on rust [Kanazawa et al. 2015]. Although the rust forming processes vary according to coating rain-water and seawater, dissolved oxygen contents of them and flowing water effects, no rust forming methods which have examined the object geometry of models and chemical reaction processes exist as far as we know. Our proposed method calculates water flowing on 3D models to reproduce the process of corrosion which advances from the surface region coated with water. Our corrosion simulation model takes into account the quantity of coating water and the chemical reaction processes. As a result, we confirm that the images close to the rust formed in reality can be obtained.

Mesh Simplification Using Hybrid Saliency

This research presents a view-independent saliency model, which takes the effect of both color information and geometric information into account. The proposed method can simplify a mesh by dropping low-attention places while protecting the high-attention places. Multi-platform game contents are becoming a trend in the gaming field of CG in recent years. One of the problems in developing such game contents is the difference of the processing performance between the platforms. A content that runs smoothly on high processing-performance platform may not run smoothly on the lower-performance platforms. This problem can be solved by mesh simplification, which reduces the number of polygons in the mesh while preserving the overall shape, volume and boundaries as much as possible. Fewer polygons require less processing performance, and the simplified mesh can be processed smoothly even in low processing-performance platform. The proposed method simplifies a mesh in three steps. First, it takes a triangular polygonal mesh for simplification as input. Then, it calculates a view-independent hybrid saliency for each vertex of the input mesh. The hybrid saliency is evaluated from the curvature, the mesh saliency, the maximum, minimum, and average values of multiview image saliencies. Last, it simplifies the input mesh by dropping low hybrid saliency vertices. The experiments indicated that the proposed method yields a better result than existing methods.

A video summarization technique of animation products according to film comic format

1 ishikawatm@stf.teu.ac.jp 1. はじめに 近年、インターネットによる動画配信などにより、 消費者が触れることのできる情報は増加した。特にア ニメ作品の動画配信の増加が顕著であり、無料有料問 わず、多くの動画配信サイトが存在する。しかしなが ら、時間や場所などの制約がないインターネットであ るだけに、非常に多彩な作品が存在し、動画であるア ニメ作品の消費には、まとまった時間が必要であり、 すべての人が手軽に楽しめるとは限らない。 このような背景から、映像要約に関する研究も盛ん に行われ、必要最低限の情報を抜き出す手法として漫 画形式の映像要約も注目されている [1-3]。これらの研 究は、動画以外の情報を必要とする限定的な条件であ り、シーンの重要度からキーフレームを検出する手法 ながら、そこに漫画の技法を適用しておらず、漫画形 式の映像要約としては不十分である。 そこで、本研究ではフィルムコミックという書籍メ ディアに着目した。フィルムコミックは、レイアウト と描画を同時に作成する漫画とは異なり、既にアニメ 作品として仕上がったものを漫画形式に編集したもの である。フィルムコミックの製作は、編集するアニメ 作品の長さが 1 時間を超えるものが多く存在するため、 利用フレームの選択やレイアウトは非常に手間のかか る作業である。 本研究では、フィルムコミックの編集作業を短縮す るために、入力したアニメ作品から、漫画技法を考慮 した映像要約を行うことを目的とする。入力したアニ メ作品から、シーンの切り替え地点のフレームを判定 し抽出するだけでなく、コマ割りに利用できる見栄え の良いフレームを検出する。また顔検出を用いて、漫 画のコマ割りの形状や大きさとのマッチングを行い、 フィルムコミックのようなレイアウト画像を出力する までの処理を、自動で行えるようにすることを目指す。