Papers by Doug L. James


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Phong Deformation: A better C0 interpolant for embedded deformation

Doug L. James
July 2020

Physics-based simulations of deforming tetrahedral meshes are widely used to animate detailed embedded geometry. Unfortunately most practitioners still use linear interpolation (or other low-order schemes) on tetrahedra, which can produce undesirable visual artifacts, e.g., faceting and shading artifacts, that necessitate increasing the simulation's spatial resolution and, unfortunately, cost. In this paper, ... more

Paper (PDF)

Video


Sharp Kelvinlets: Elastic Deformations with Cusps and Localized Falloffs

Fernando de Goes, Doug L. James
July 2019

In this work, we present an extension of the regularized Kelvin-let technique suited to non-smooth, cusp-like edits. Our approach is based on a novel multi-scale convolution scheme that layers Kelvinlet deformations into a finite but spiky solution, thus offering physically based volume sculpting with sharp falloff profiles. We also show ... more

Paper (PDF)

Video

Additional materials: [code.zip]


Dynamic Kelvinlets: Secondary Motions based on Fundamental Solutions of Elastodynamics

Fernando de Goes, Doug L. James
May 2018

We introduce Dynamic Kelvinlets, a new analytical technique for real-time physically based animation of virtual elastic materials. Our formulation is based on the dynamic response to time-varying force distributions applied to an infinite elastic medium. The resulting displacements provide the plausibility of volumetric elasticity, the dynamics of compressive and shear ... more

Paper (PDF)

Video

Additional materials: [code.zip], [suppl.zip]

Available as Pixar Technical Memo #18-05


Regularized Kelvinlets: Sculpting Brushes based on Fundamental Solutions of Elasticity

Fernando de Goes, Doug L. James
May 2017

We introduce a new technique for real-time physically based volume sculpting of virtual elastic materials. Our formulation is based on the elastic response to localized force distributions associated with common modeling primitives such as grab, scale, twist, and pinch. The resulting brush-like displacements correspond to the regularization of fundamental solutions ... more

Paper (PDF)

Video: Regularized Kelvinlets

Video: Additional example with ~2M triangles

Additional materials: [multiScaleDerivation.pdf], [gradDerivation.pdf]

SIGGRAPH 2017

Available as Pixar Technical Memo #17-03