Essential graph Motion graph - Inria › hal-01212168 › file › Poster_3dv.pdfInitial graph...

Video based Animation Synthesis with the Essential GraphAdnane Boukhayma Edmond Boyer

LJK, Université Grenoble Alpes, Inria Grenoble Rhône-Alpes, France

Problem

Given a set of recorded elementary 4D models, generate realistic new animations that satisfy user specified constraints.

Input: Video based temporally consistent Output: Novel, user-guided realistic surface animation.mesh sequences of cyclic or acyclic

elementary motions.

Approach

Data organizing structure

• Initial graph instance:Node = frame, edge = transition.

• Complete directed graph:All nodes connected with a realism cost.

• Essential sub-graph:Extraction of the union of shortest pathtrees rooted at every node.

• Minimum cost graph walk:Graph search for a walk satisfying userhigh-level constraint.

Pose parametrization

Pose distance based onlocal deformationgradients.

Pose interpolation usingPoisson reconstructionof mesh deformed withgeodesically interpolateddeformation gradients.

Interpoalted transition

Generation of a transition from frame i to frame j through grad-ual frame blending with optimal segment lengths li and lj , andtemporal warps wi and wj w.r.t surface deformation cost.

Contributions

• The essential graph, an optimal structure for motion dataorganization and reuse.

• Dynamic Time Warping & Variable Length BlendedSegments, for more realistic interpolated motion transitions.

Qualitative comparison

Interpolated transition

Combining dynamictime warping and variablelength blended segments(a), compared to a standardinterpolated transition (b).

Organizing data structure

Illustration of a motiongraph’s (b) failureto find a graph walk asshort and costless as theessential graph (a).

Quantitative comparison

Organizing data structure

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(a) Motion graphEssential graph

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(b) Motion graphEssential graph

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(c) Motion graphEssential graph

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(d) Motion graphEssential graph

Costs of all optimal paths joining all pairs of frames in thedataset for a motion graph and an essential graph. Dan dataset:(a)α = 0.01, (b)α = 0.1. JP dataset: (c)α = 0.01, (d)α = 0.1.