Autodesk, Inc.

Avid Technology Limited

Jérôme Couture-Gagnon

Ian F Stewart

Dominic Laflamme

Peter Zion

Maxime Beaudry

Ronald Beirouti

An operator graph representing three-dimensional animation can be analyzed to identify subgraphs of the operator graph in which operators are not required to operate in a serialized manner. Such a condition may arise, for example, when two operators are not dependent on each other for data. This condition may arise when the operators are operating on different elements in a scene. Such operators may be evaluated in parallel. To identify these operators, a dependency graph is created. The dependency graph indicates which operators have inputs that are dependent on outputs provided by other operators. Using this graph, operators that are independent of each other can be readily identified. These operators can be evaluated in parallel. In an interactive editing system for three-dimensional animation or other rich media, such an analysis of an operator graph would occur when changes are made to the animation. The creation and use of the dependency graph enables faster processing of a scene while changes to the scene are being made.

Efficient processing of operator graphs representing three-dimensional character animation

Smoothing operations on a three-dimensional geometrical primitive, such as a mesh, are restricted by filtering the set of smoothing vectors to apply a user-selected restriction to the set of vectors. The user-selected restriction limits the set of smoothing vectors according to a normal of a surface corresponding to the primitive. The filtered set of vectors are applied to the primitive to smooth the primitive. Thus, smoothing may be applied proportionally to the convexity or concavity of the surface. Smoothing also may be applied to move a control point of the primitive, such as a vertex in a mesh, only in a direction parallel to the normal of the surface at that control point or perpendicular to the normal of the surface at that control point. Each control point also may be reprojected after smoothing onto the original surface along the normal of the smoothed surface, or the normal of the original surface.

Restricting smoothing operations on a three-dimensional geometric primitive according to a surface normal

Attributes associated with components of a three-dimensional source geometry may be transferred to a target geometries having an arbitrarily different topology. The two geometries are placed in a general alignment in three dimensions. Correspondences are found between anchors for attributes in the target geometry and anchors for attributes in the source geometry. The identified correspondence locations on the source geometry are locally redistributed so as to ensure that concave regions of the source geometry are mapped to the target geometry, and that convex edges or vertices of the source geometry do not map to a large area on the target geometry. Attribute discontinuities in the source geometry are preserved in the target geometry by relating discontinuous edges in the source geometry to the target geometry. This relationship may map each discontinuous edge in the source geometry locally to the target geometry. Alternatively, this relationship may involve mapping discontinuous paths globally to the target geometry. Thus, the quality of attribute transfer is improved by reducing distortions introduced by the method through which correspondence between a target geometry and a source geometry is determined and/or by preserving discontinuities in attributes from the source geometry by relating discontinuous edges in the source geometry to the target geometry.

Transfer of attributes between geometric surfaces of arbitrary topologies with distortion reduction and discontinuity preservation

To preserve flow line characteristics in a reduced mesh, the mesh is reduced by identifying one or more flow lines in the mesh and removing a plurality of edges associated with the one or more flow lines. Such a reduction may be achieved by identifying a set of connecting edges between adjacent flow lines, or between portions of adjacent flow lines, and contracting these connecting edges in one step. The set of connecting edges to contract in any given iteration may be identified based on the flow lines. A cost metric also may be used to decide which connecting edges are in the set to be contracted. In a first technique, a lowest cost edge is selected, and other connecting edges between the same adjacent flow lines are added to the set until a threshold condition is met. This threshold condition balances preservation of flow lines with preservation of attributes. In a second technique, several sets of connecting edges are identified. The set of connecting edges with the lowest cost is contracted in each iteration, and the cost of each set is updated after each iteration.

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Longueuil, Canada

Jérôme Couture-Gagnon