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\subsection{Algorithm ``How?''} |
\subsection{Algorithm ``How?''} |
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Surface defined by $(x, y, f(x,y))$. |
The jagged shape is defined by a surface $(x, y, f(x,y))$, |
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The jagged version of an edge in the $z=0$ plane is obtained by first |
where $-1 \le f(x,y) \le 1$ and $(x,y,0)$ is paper location. |
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intersecting another plane going through the edge with the surface |
The shape of an edge torn along a line is obtained by intersecting |
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and then ``projecting'' the intersection to the $z=0$ plane. |
the surface with a plane cutting through the tearing line. |
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XXX: projecting so that the desired ``shape width'' is obtained. |
The intersection is then rotated around the tearing line until |
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it is horizontal and stretched so that $z = -1$ and $z = 1$ lines |
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of the cutting plane correspond to the desired maximum positive |
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and negative displacements of the edge. |
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If the cutting plane is normal to $z=0$ plane, the edge is attached. |
If the cutting plane is vertical, the shape of the torn edge is attached. |
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Otherwise, the edge may be sprinkled. |
If the angle between $z = 0$ plane and the cutting plane is |
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small enough, the plane will cut off maxima of the surface, |
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producing a sprinkeld shape. |
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\section{Hardware-accelerated implementation} |
\section{Hardware-accelerated implementation} |
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