线条能够以相当少的可视信息来有效地表示一个三维模型的形状.利用图形硬件的高度并行处理能力,文中提出了一种新的基于物体空间的线条绘制方法.对于一个光滑物体形状,新型的Suggestive轮廓线能够结合侧影轮廓线来生成非常好的视点相关的线条效果.并且,最新被引入到Direct3D10流水线的几何着色器能处理三角形图元数据及输出零个或多个线条图元.文中提出了一种并行化的线条绘制方法,能够直接在几何着色器中抽取三维的特征线条.该方法能根据视点与模型的距离自动地选取合适比例的线条进行绘制,绘制的线条平滑,绘制速度快.在文章最后给出的许多实验示例证实了该方法的效果.
This paper presents a new object-space based algorithm for rendering a 3D model as a line drawing using graphics hardware, based on the insight that a line drawing can effectively convey shape using remarkably minimal visual content. Suggestive contours, a new type of line can be combined with silhouettes to produce impressive view-dependent line drawing of smooth shapes. In addition, geometry shader, which is newly introduced into the Direct3D 10 pipeline, can process per-triangle primitive data and output zero or more line primitives. This paper proposes a parallelized line drawing approach that directly extracts 3D sparse linear features in geometry shader. The method selects lines at an appropriate scale automatically, and exhibits good frame-to-frame coherence at interactive rates. The implementation of the algorithm is straightforward, and several experimental examples are given at the end of the paper to demonstrate the effectiveness of our approach.