Adaptive Cube Tessellation for Topologically Correct Isosurfaces

Three dimensional datasets representing scalar fields are frequently rendered using isosurfaces. For datasets arranged as a cubic lattice, the marching cubes algorithm is the most used isosurface extraction method. However, the marching cubes algorithm produces some ambiguities which have been solved using different approaches that normally imply a more complex process. One of them is to tessellate the cubes into tetrahedra, and by using a similar method (marching tetrahedra), to build the isosurface. The main drawback of other tessellations is that they do not produce the same isosurface topologies as those generated by improved marching cubes algorithms. We propose an adaptive tessellation that, being independent of the isovalue, preserves the topology. Moreover the tessellationallows the isosurface to evolve continuously when the isovalue is changed continuously.

UsedSoft and the Big Bang Theory: Is the e-Exhaustion Meteor about to Strike?

Since the UsedSoft ruling of the CJEU in 2012, there has been the distinct feeling that – like the big bang - UsedSoft signals the start of a new beginning. As we enter this brave new world, the Copyright Directive will be read anew: misalignments in the treatment of physical and digital content will be resolved; accessibility and affordability for consumers will be heightened; and lock-in will be reduced as e-exhaustion takes hold. With UsedSoft as a precedent, the Court can do nothing but keep expanding its own ruling. For big bang theorists, it is only a matter of time until the digital first sale meteor strikes non-software downloads also. This paper looks at whether the UsedSoft ruling could indeed be the beginning of a wider doctrine of e-exhaustion, or if it is simply a one-shot comet restrained by provisions of the Computer Program Directive on which it was based. Fighting the latter corner, we have the strict word of the law; in the UsedSoft ruling, the Court appears to willingly bypass the international legal framework of the WCT. As far as expansion goes, the Copyright Directive was conceived specifically to implement the WCT, thus the legislative intent is clear. The Court would not, surely, invoke its modicum of creativity there also... With perhaps undue haste in a digital market of many unknowns, it seems this might well be the case. Provoking the big bang theory of e-exhaustion, the UsedSoft ruling can be read as distinctly purposive, but rather than having copyright norms in mind, the standard for the Court is the same free movement rules that underpin the exhaustion doctrine in the physical world. With an endowed sense of principled equivalence, the Court clearly wishes the tangible and intangible rules to be aligned. Against the backdrop of the European internal market, perhaps few legislative instruments would staunchly stand in its way. With firm objectives in mind, the UsedSoft ruling could be a rather disruptive meteor indeed.