Texts paying particular attention to implicit surfaces ...

Figure 4. Reference frames (dashed) at n1 and n2, nearest points on triangles P1 and P2 to vertex q; also shown are SF1 and SF2, stick-figure reference frames that control the medial vertex m. 5. Convolution. A convolution field is produced around the medial by convolving a three-dimensional cubic filter (for example) with the medial. ................
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