5.2008, 2

Rendering Falling Leaves on Graphics Hardware

GRAPP 2007 Special Issue

Pere-Pau Vázquez et al.

There is a growing interest in simulating natural phenomena in computer graphics applications. Animating natural scenes in real time is one of the most challenging problems due to the inherent complexity of their structure, formed by millions of geometric entities, and the interactions that happen within. An example of natural scenario that is needed for games or simulation programs are forests. Forests are difficult to render because the huge amount of geometric entities and the large amount of detail to be represented. Moreover, the interactions between the objects (grass, leaves) and external forces such as wind are complex to model. In this paper we concentrate in the rendering of falling leaves at low cost. We present a technique that exploits graphics hardware in order to render thousands of leaves with different falling paths in real time and low memory requirements.

[Submitted: May 31st, 2007 | In Peer-Review: June 6th, 2007 | Resubmitted: October 25th, 2007 | Accepted: September 12th, 2007 | Published: April 15th, 2008 ]

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5.2008, 3

Adaptive Cube Tessellation for Topologically Correct Isosurfaces

GRAPP 2007 Special Issue

Francisco Velasco et al.

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.

[Submitted: May 7th, 2007 | In Peer-Review: May 8th, 2007 | Resubmitted: September 25th, 2007 | Accepted: September 12th, 2007 | Published: April 28th, 2008 ]

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