Motion Interpolation (computer graphics) Contents Implementation Example References Navigation menulink to itrelated articlesFind link tool"Verbs and Adverbs: Multidimensional Motion Interpolation""Interpolation Synthesis of Articulated Figure Motion""Parameterization of Motions in Large Data Sets"

Animation


keyframingmotion capturewalk cycleUnity game engine








Motion interpolation is a programming technique in data-driven character animation that creates transitions between example motions and to extrapolates new motions.


Example motions are often created through keyframing or motion capture. However, keyframing is labor-intensive and lacks varieties of motion, and both processes result in motions that are time-consuming to alter.
Motion interpolation provides a much faster alternative to creating new motions through the same means.[1]




Contents





  • 1 Implementation

    • 1.1 Simulated Figure


    • 1.2 Interpolation


    • 1.3 Inverse Kinematics


    • 1.4 Searching For Relevant Motions



  • 2 Example


  • 3 References




Implementation


Formerly, a popular method of simulating a character's movement involved storing a variety of motions and choosing the most appropriate one during run-time.
Unfortunately, storage limitations resulted in repetitive or imperfect results.
Instead, with some additional computation, new, desired motions can be created by interpolating preexisting, similar motions.
Using interpolation, motions can be generated in real time while preserving the realistic qualities of the example motions.[2]



Simulated Figure


The simulated figure that is manipulated to show the motion is represented as a hierarchical connection of rigid links by joints.
The root of the hierarchy has six degrees of freedom: three degrees for the figure's position and three degrees for the figure's rotation.
This representation is sufficient, because knowing only the degrees for each joint and the root, the figure can be rendered at any time.[1]



Interpolation


Suppose that for a desired motion, "walk," there exist two example motions that convey different moods (e.g., happy and sad). A happy walking motion may be characterized by a simulated figure's posture being upright and its gait being energetic and fast-paced. A sad walking motion may be characterized by a slouched posture and a slow gait.[1]


To interpolate these motions, they must be in canonical form. This means that their times must be made generic so that significant structural events occur simultaneously. To elaborate, the two example walking motions may vary in time, as the happy walk is described as fast-paced and the sad walk is described as slow. However, scaling their lengths of time to be equivalent is not sufficient for interpolation. This is because the slow walking motion is not simply an elongation of the happy walking motion. These motions must have their walk cycle key frames aligned, so that at a given generic time, both motions make a forward point contact.[1]


For a neutral walking motion that is neither (or equally) happy or sad, the corresponding degrees of freedom for the existing motions are used for interpolation. As a result, a tuple of degrees of freedom is created for a simulated figure walking a neutral walking motion at a generic time.
Alternatively, if the mood of the simulated figure were to change in real time from happy to sad, the interpolation would be more influenced by the happy walking motion at the start of the transition. Towards the end of the transition, the interpolation would be more influenced by the sad walking motion until the figure simply walks the sad walking motion.[1]


A transition between two types of motions (e.g., a walking motion and a running motion) involves the interpolation of velocities. This ensures a smooth transition. A transition between two types of motions requires either be a generic time frame where both types of motions share structural similarities, or a series of motions with transitional periods that eventually reach the desired type of motion.[1]



Inverse Kinematics


Inverse kinematics can be used with real-time motion interpolation to create interactions with a virtual environment. As aforementioned, there is a necessary process of annotating example motions with significant structural events. These annotations allow for the reparameterization of time to generic time.
However, these annotations can also be used to specify periods where inverse kinematics should be used.
For example, during a forward point contact in a walk cycle, kinematic constraints should be enabled so that the foot of the simulated figure is flush with the floor of the virtual environment.[1]



Searching For Relevant Motions


For large sets of example motions, the process of finding relevant results is not trivial.
Therefore, methods have been developed to extract motions based on logical similarities and to combine these results into a continuous, branching space of motions that can be searched.[3]



Example


The process of annotating example motions and applying inverse kinematics is similar to the process the Unity game engine uses to have inverse kinematics with animations.



References




  1. ^ abcdefg Rose, Charles (September 1998). "Verbs and Adverbs: Multidimensional Motion Interpolation". www.vuse.vanderbilt.edu. Retrieved 2016-12-14..mw-parser-output cite.citationfont-style:inherit.mw-parser-output .citation qquotes:"""""""'""'".mw-parser-output .citation .cs1-lock-free abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .citation .cs1-lock-subscription abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registrationcolor:#555.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration spanborder-bottom:1px dotted;cursor:help.mw-parser-output .cs1-ws-icon abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/12px-Wikisource-logo.svg.png")no-repeat;background-position:right .1em center.mw-parser-output code.cs1-codecolor:inherit;background:inherit;border:inherit;padding:inherit.mw-parser-output .cs1-hidden-errordisplay:none;font-size:100%.mw-parser-output .cs1-visible-errorfont-size:100%.mw-parser-output .cs1-maintdisplay:none;color:#33aa33;margin-left:0.3em.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-formatfont-size:95%.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-leftpadding-left:0.2em.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-rightpadding-right:0.2em


  2. ^ Wiley, Douglas (November 1997). "Interpolation Synthesis of Articulated Figure Motion" (PDF). www.computer.org. Retrieved 2016-12-14.


  3. ^ Kovar, Lucas (2004). "Parameterization of Motions in Large Data Sets". research.cs.wisc.edu/. Retrieved 2016-12-14.









Popular posts from this blog

Solar Wings Breeze Design and development Specifications (Breeze) References Navigation menu1368-485X"Hang glider: Breeze (Solar Wings)"e

Kathakali Contents Etymology and nomenclature History Repertoire Songs and musical instruments Traditional plays Styles: Sampradayam Training centers and awards Relationship to other dance forms See also Notes References External links Navigation menueThe Illustrated Encyclopedia of Hinduism: A-MSouth Asian Folklore: An EncyclopediaRoutledge International Encyclopedia of Women: Global Women's Issues and KnowledgeKathakali Dance-drama: Where Gods and Demons Come to PlayKathakali Dance-drama: Where Gods and Demons Come to PlayKathakali Dance-drama: Where Gods and Demons Come to Play10.1353/atj.2005.0004The Illustrated Encyclopedia of Hinduism: A-MEncyclopedia of HinduismKathakali Dance-drama: Where Gods and Demons Come to PlaySonic Liturgy: Ritual and Music in Hindu Tradition"The Mirror of Gesture"Kathakali Dance-drama: Where Gods and Demons Come to Play"Kathakali"Indian Theatre: Traditions of PerformanceIndian Theatre: Traditions of PerformanceIndian Theatre: Traditions of PerformanceIndian Theatre: Traditions of PerformanceMedieval Indian Literature: An AnthologyThe Oxford Companion to Indian TheatreSouth Asian Folklore: An Encyclopedia : Afghanistan, Bangladesh, India, Nepal, Pakistan, Sri LankaThe Rise of Performance Studies: Rethinking Richard Schechner's Broad SpectrumIndian Theatre: Traditions of PerformanceModern Asian Theatre and Performance 1900-2000Critical Theory and PerformanceBetween Theater and AnthropologyKathakali603847011Indian Theatre: Traditions of PerformanceIndian Theatre: Traditions of PerformanceIndian Theatre: Traditions of PerformanceBetween Theater and AnthropologyBetween Theater and AnthropologyNambeesan Smaraka AwardsArchivedThe Cambridge Guide to TheatreRoutledge International Encyclopedia of Women: Global Women's Issues and KnowledgeThe Garland Encyclopedia of World Music: South Asia : the Indian subcontinentThe Ethos of Noh: Actors and Their Art10.2307/1145740By Means of Performance: Intercultural Studies of Theatre and Ritual10.1017/s204912550000100xReconceiving the Renaissance: A Critical ReaderPerformance TheoryListening to Theatre: The Aural Dimension of Beijing Opera10.2307/1146013Kathakali: The Art of the Non-WorldlyOn KathakaliKathakali, the dance theatreThe Kathakali Complex: Performance & StructureKathakali Dance-Drama: Where Gods and Demons Come to Play10.1093/obo/9780195399318-0071Drama and Ritual of Early Hinduism"In the Shadow of Hollywood Orientalism: Authentic East Indian Dancing"10.1080/08949460490274013Sanskrit Play Production in Ancient IndiaIndian Music: History and StructureBharata, the Nāṭyaśāstra233639306Table of Contents2238067286469807Dance In Indian Painting10.2307/32047833204783Kathakali Dance-Theatre: A Visual Narrative of Sacred Indian MimeIndian Classical Dance: The Renaissance and BeyondKathakali: an indigenous art-form of Keralaeee

Method to test if a number is a perfect power? Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 23, 2019 at 00:00UTC (8:00pm US/Eastern)Detecting perfect squares faster than by extracting square rooteffective way to get the integer sequence A181392 from oeisA rarely mentioned fact about perfect powersHow many numbers such $n$ are there that $n<100,lfloorsqrtn rfloor mid n$Check perfect squareness by modulo division against multiple basesFor what pair of integers $(a,b)$ is $3^a + 7^b$ a perfect square.Do there exist any positive integers $n$ such that $lfloore^nrfloor$ is a perfect power? What is the probability that one exists?finding perfect power factors of an integerProve that the sequence contains a perfect square for any natural number $m $ in the domain of $f$ .Counting Perfect Powers