We study the problem how to draw a planar graph crossing-free such that every vertex is incident to an angle greater than π. In general a plane straight-line drawing cannot guarantee this property. We present algorithms which construct such drawings with either tangent-continuous biarcs or quadratic Bézier curves (parabolic arcs), even if the positions of the vertices are predefined by a given plane straight-line drawing of the graph. Moreover, the graph can be drawn with circular arcs if the vertices can be placed arbitrarily. The topic is related to non-crossing drawings of multigraphs and vertex labeling.

中文翻译：

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平面图的尖图。

我们研究如何绘制无交叉平面图，使得每个顶点都以大于π 的角度入射。一般来说，平面直线图不能保证这种性质。我们提出了用切线连续双弧或二次贝塞尔曲线（抛物线弧）构建此类绘图的算法，即使顶点的位置是由图形的给定平面直线绘图预定义的。而且，如果顶点可以任意放置，图形也可以画成圆弧。该主题与多重图和顶点标记的非交叉绘图相关。