We present Implicit Skinning a real time method for character skinning. The technique is a post process applied over a geometric skinning (such as linear blending or dual-quaternions) which handles the self-collisions of the limbs by producing skin contact effects and plausible organic bulges in real-time. In addition we avoid the usual collapsing or bulging artifacts seen with linear blending or dual quaternions at the skeleton's joint.
To achieve these effects we need a volumetric representation of the mesh. Implicit Skinning's idea is to use a set of implicit surfaces (3D distance-fields/scalar-fields), rather than tetrehadral/voxel mesh and a slow physical simulation. For each limb, we automatically generate the implicit surface shape, and use it to adjust the position of the geometric skinning's vertices without loss of details.
As Implicit Skinning acts as a post-process, it fits well into the standard animation pipeline. Moreover, it requires no intensive computation step such as an explicit collision detection between triangles, and therefore provides real-time performances.
Rodolphe Vaillant(1,2), Loïc Barthe(1), Gaël Guennebaud(3), Marie-Paule Cani(4),
Damien Rhomer(5), Brian Wyvill(6), Olivier Gourmel(1) and Mathias Paulin(1)
(1)IRIT - Université de Toulouse, (2)University of Victoria, (3)Inria Bordeaux,
(4)LJK - Grenoble Universités - Inria, (5)CPE Lyon - Inria, (6)University of Bath
We thank artists, companies and universities who provided us with nice 3D models. Juna model comes from Rogério Perdiz. Dana and Carl models from the company MIXAMO. Finally the famous armadillo model comes from the Standford university 3D scan repository.
We also thank the blender foundation for providing everyone with the Blender software which we used to do some of the enhanced rendering in the video. Rendering setup is a modified version of the Sintel Lite rendering setup.
This work has been partially funded by the IM&M project http://www.irit.fr/~Loic.Barthe/imm.php (ANR-11-JS02-007) and the advanced grant EXPRESSIVE from the European Research council. Partial funding also comes from the Natural Sciences and Engineering Research Council of Canada, the GRAND NCE, Canada and Intel Corps. Finally, this work received partial support from the Royal Society Wolfson Research Merit Award.
I just uploaded a new version of Ionic you can download here:
This is the last sim I did (Sim in Maya, render in Houdini), 400 frames simulated (around 4hrs), although I rendered around 250. I'd love to simulate many more particles, but I guess I'll have problems meshing & render them with my 8 gigs of ram, so for now I'll limit my sims to just around 10 millions :)
This video demonstrates how to use a series of tools to build a complex crumbling effect in Houdini 15. The video shows how to use groups to focus fracturing on a specific area of a mesh and how to use an Attribute Wrangle to create your own density style attribute for scattering. In the process we fracture, create rigid body objects and glue the pieces back together. The video demonstrates how to use the Glue Constraint Strength to add a kind of slow motion effect to the crumble. The video shows how to use the Debris tool to add particles to the fracture pieces and setup a custom activation expression to better control how particles are emitted from the fracture areas. We then use the Debris particles to supply the PyroFX tools with a source for making Smoke. The video shows how to add a different material to the inside and outside parts of the fracture pieces. The video finishes up by reusing the initial fracture pieces from the font as smaller debris shards to replace the standard particle spheres for rendering.