Modifying Soft Tissue Models: Progressive Cutting with Minimal New Element Creation

A level set method for ductile fracture

“…Early approaches typically made use of simple separation along mesh element boundaries [Norton et al 1991;Mazarak et al 1999;Smith et al 2001;Müller et al 2001] or even element deletion [Forest et al 2002]. The available geometric detail in this type of approach was increased somewhat by subdivision of elements in the mesh prior to splitting [Mor and Kanade 2000;Bielser and Gross 2000]; however, this tended to introduce elements with poor aspect ratios. More geometrically rich fracture patterns were generated by allowing failure along more arbitrary paths (albeit with the expense of re-meshing) [Neff and Fiume 1999;O'Brien and Hodgins 1999;O'Brien et al 2002].…”

A Hybrid Cutting Approach for Hysteroscopy Simulation

“…In the context of medical applications, this was first introduced in [12] for cutting of tetrahedral meshes with predefined planes. This approach has been refined in [16], where partial incision of mesh elements as well as progressive cutting is taken into account. Finally, [1] discusses the use of a state machine to keep track of different incisions in tetrahedral meshes.…”

“…Another negative factor is the reduction in element sizes. Deformation stability problems were reported [16], which required a significant reduction of the time step, thus rendering real-time simulation intractable.…”

“…Including these procedures in our simulator system necessitates updates of the underlying tissue model. Different approaches for handling cutting have been proposed, which can be summarized into three major categories: straight-forward element deletion [2,7,5], mesh subdivision [12,16,8,3,1] and topology adaptation [20,17]. While the first method is not appropriate for a realistic simulator, the latter two have produced reasonable results.…”

Real-Time Interactions Using Virtual Tools

“…In the second frame, the surfaces relax as the free edges are formed. Using the same face-based cases, we can compose overall tetrahedral cases similar to [3] using only the minimal number of new tetrahedra for each cut. Figure 5 demonstrates the ability to cut a volumetric object composed of tetrahedra.…”