Introduction Background Design Implementation Results 2 - PowerPoint PPT Presentation

Introduction Background Design Implementation Results 2

Introduction Use dynamics to interpret motion data in an artistically-inspired way • Motion sculptures that represent moments in time, yet escape the constraints • of the human range of motion Museum walkthrough to showcase the sculptures • 3

Capturing Motion Playback sequence of still images to produce an animation • Muybridge’s camera array • Hea ead-spr pring by Eadward Muybridge, 1887 Bullet et Time e by Manex VFX, 1 1999 4

Motion and Art Marey’s Chronophotography Somersault over a So an o obstacle by Etienne-Jul ules s Marey ey, 1 1884 • Inspired French Cubism & Italian Futurism • Moved away from analytical portrayals of movement • 5

French Cubism Inspired by the idea of motion as the subject matter • Reconstruction of time and space • Multiple viewpoints together • Geometric shapes and repetition • Nude Descend nding ng a a Staircase se, N No. 2 2 by Marcel D Duchamp, 1912 6

Italian Futurism The Cellist by Anton Braga gagl glia, 1 1913 Inspired by the innovations in photography • Photodynamism, dynamic photography • Focused on overall motion • Time is the brush on a spatial canvas • Aimed to provoke a sensation • 7

Performance Capture Hea ead-spr pring by Eadward Muybridge, 1887 Dawn o of t the e Planet et o of the A e Apes es, 2014 014 Nike S Sports s Rese search L h Lab 8

Using Technology to Create Art Line Drawing as a Dynamic Process Donald House and Mayank Singh, Texas A&M University, 2007 Simulates gestural, free-flowing drawing techniques and incorporates momentum and pen pressure 9

Designing the Environment Based on modern art museums Inspired by dance and stage • • Theatrical lighting • Accentuates form and contour • Guides narrative and focus • Shapes and shadows • Caught ht by David P Parsons 10

Designing the Sculptures Basis in reality, yet impossible • Recreate the sensation of motion • Inspired by Cubism, Futurism, • Light-painting photography Breakdance Light Painting by J Joanna Jask skolsk ska 11

Working with Motion Capture Data • Reflective Markers and Infrared Cameras • Spatial location of markers used to rebuild joint rotations • Several ways of translating the data 12

Applying Dynamics Motion capture animation is transferred to a set of control points • Corresponding set of pen points • Spring connection between each pair • Preserves momentum and extends reach • Creates smooth trajectory of motion • Source: Line Drawing as a a Dynamic Process ss by D Donald House a and May ayan ank Singh, 2007 007 13

Springs, Proportional-Integral-Derivative Controller t current time 𝑒 2 𝑞 𝑛 mass of pen 𝑒𝑒 2 = − 1 𝑙𝑓 + 𝑒 𝑒𝑒 𝑒𝑒 + 𝑑 � 𝑓𝑒𝑒 𝑛 𝑞 position of pen 𝜐 position of control  𝑓 error 𝑙 , 𝑒 , 𝑑 corrective gains 𝑒 2 𝑞 𝑒𝑒 2 = −𝜕 2 𝑓 − 2𝜂𝜕 𝑒𝑒 𝑒𝑒 𝜕 natural frequency 𝜂 damping constant Source: Line Drawing as a a Dynamic Process ss by D Donald House a and May ayan ank Singh, 2007 007 14

Applying the Forces Control points from motion capture data • Pen points created as particle system • Spring forces implemented in Python/VEX code • 15

Point Attributes Varying spring constants • Velocity-based scaling • Color variation • Motion C Capture Data Spring Forces, V Variation 1 1 Spring Forces, V Variation 2 2 Spring Forces, V Variation 3 3 16

Building the Sculptures 5 small animated sculptures • Pen points create trail • Simple extrusions along curves • Animation controls • Time offsets within sculpture • Direction variation • Dissolve Effect • Noise Effect • 17

Building the Sculptures 5 large stationary sculptures • More complexity • Not restricted to simple extrusions • Layers of motion • Noise patterns • Refinement of “unnatural” • imperfections 18

Building the Sculptures Using OpenVDB to fix non-manifold geometry 1. 3. Convert Level elset et back t to mesh sh Mesh w with i intersections 2. Converted to OpenVD VDB Level elset et Smooth m mesh without i inner p penetrations 19

Attribute-based Shading Create a “hand-made” feel by adding specular and diffuse noise, grunge, and bump Unalter ered ed shader Attribute v visualization Attribute-based s shading Edge detection by measuring curvature of surface • Mixed with noise pattern • Artist can paint on attributes • 20

Results • Workflow can be applied to any animated point data • Motion Capture • Keyframe Animation • Particle Systems • Custom VEX spring solver in Houdini DOPs • Point manipulation tools • Procedural modeling tools 24

Sculpture from a animated s sphere: with ( (left) a and without (right) spring dynamics Sculpture from p particle s system w with s spring dynamics 25

Thank you 26

Questions 27