Procedural Animation
Below is a recent research paper I’ve done on procedural animation over the duration of one month in between classes. I take no credit for the ideas presented, as they are not original. To be more precise it is a paper better served as reference notes for future work in the area.
Work Cited on Procedural Animation
A research paper that spans only a single month is due this Wednsday and I’ve just finished compiling all my notes. I can’t say it was easy, some of the material i stumbled upon was simply beyond me. I’ll attempt at working these into a slightly better order at a later time, but for the time being here is the list.
[00] Lecture notes from Real Time Animation by Shawn Stafford. FullSail University.
[01] Learning to Move Autonomously in a Hostile World, Leslie Ikemoto, University of California at Berkeley. http://www.animate-me.com/~leslie/papers/moveAutonomous.pdf
[02] Quick Transitions with Cached Multi-way Blends, Leslie Ikemoto, University of California at Berkeley. http://www.animate-me.com/~leslie/papers/i3d2007.pdf
[03] Ken Perlin’s Experiments on Procedural Animation, http://www.mrl.nyu.edu/~perlin/
[04] Inverse Kinematics by Hugo Elias, http://freespace.virgin.net/hugo.elias/models/m_ik.htm
[05] Inverse Kinematics – Improved Meathods by Hugo Elias, http://freespace.virgin.net/hugo.elias/models/m_ik2.htm
[06] The Matrix and Quaternion FAQ, http://web.archive.org/web/20041029003853/http:/www.j3d.org/matrix_faq/matrfaq_latest.html#Q47
[07] Physics Based Animation by Erleben, Sporring, Henriksen, Dohlmann.
[08] Inverse Kinematics Using Jacobians, http://diegopark.googlepages.com/computergraphics
[09] Motion Graphs by Lucas Kovar, University of Wisconsin Maddison. http://www.cs.wisc.edu/graphics/Papers/Gleicher/Mocap/mograph.pdf
[10] Inverse Kinematics for Humanoid Skeleton Tutorial by Jonathan Kreuzer. http://www.3dkingdoms.com/ik.htm#ikappen
[11] Planting Spores of Procedural Animation? by Dave Mark. http://aigamedev.com/discussion/planting-the-spores-of-procedural-animation
[12] The Crysis of Integrating Next-Gen Animations and AI, by Alex J. Champandard. http://aigamedev.com/reviews/crysis-animation-integration
[13] 9 Tips for Creating Rich Behaviors on a Low Animation Budget, by Alex J. Champandard. http://aigamedev.com/animation/budget-rich-behaviors
[14] The Backbone of AI Behaviors: Movement and Animation, by Alex J. Champandard. http://aigamedev.com/tutorials/backbone-behaviors-movement-animation
[15] Behavior Trees for Next-Gen AI, by Alex J. Champandard (3 parts). http://aigamedev.com/videos/behavior-trees-part1
Please bear in mind this is by no means extensive, and there are several papers I’ve read but could not recall the locations of.
Generating a Dynamic Grid Based of 4 Points
Given four points in space:
Vec3f vTopLeft, vTopRight, vBottomLeft, vBottomRight;
and a value for the cell density
unsigned int uiDensity;
We’re trying to generate a set of verticies in 3D space. These points are not limited in any way by being on the same plane.
The reason for this algorithm was originally quite simple and this solution was far from being necessary but it peaked my interest so I stuck with it.
The simple solution:
- Define all 4 edges as new vectors
- For every Edge we need to calculate the slope per axis
- vEdge[0] = vTopRight – vTopLeft;
- slope.axis_x = vEdge[0].y / vEdge[0].x; // standard rise over run (in unit length)
- slope.axis_x *= (vEdge[0].magnitude() / uiDensity); // scale to fit a square grid
- repeat for each edge
- vEdge[0] = vTopRight – vTopLeft;
- Using opposite sides of the edges connect the dots, and generate additional edges that can be added to our list of existing 4. Don’t forget to do the same for the adjacent side
- Using two nested for loops perform a line-segment on line-segment intersection tests to find the remaining points on the grid.
* the result is assumed to have equal number of points on each edge
This algorithm is not very fast, but it should get the job done. I’m interested in other approaches since this was an on the fly solution at 1:00am.
A new PS3 Tech Demo
Despite all the negative critism by the users I was truly impressed when I saw the new tech demo for the PS3, titled “Linger In Shadows“. Although very abstract, I was highly impressed with the close ups on the cat and the fur shaders. This comes a long way from Shadow of the Colossus. Other points that impressed me were the rope physics, and the depth of field (some of which I expect to be demonstrated in Insomniacs upcoming game).
This is a quick share. If you have further understanding of the graphics system please share with me what you might have thought after a closer look.