1 / 12

The Procedure of Collision Detection

The Procedure of Collision Detection. COMP7970, Spring,’07 Jian Fang. Collision Resolution. Is the process after a collision is predicted. Is complex process, sometimes: -- A collision prediction does not mean a real collision.

stormy
Download Presentation

The Procedure of Collision Detection

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Procedure of Collision Detection COMP7970, Spring,’07 Jian Fang

  2. Collision Resolution • Is the process after a collision is predicted. • Is complex process, sometimes: -- A collision prediction does not mean a real collision. -- Compute the closest contact points can be tricky. • Collision resolution may take many forms: ignored,visible actions, or invisible actions. • Includes three phases: Prologue, collision, and epilogue.

  3. Forms of Collision Resolution • Ignored: collision does not effect position and trajectory objects. • Visible Effect: Physics laws are applied, i.e., gravity and deformation. • Invisible Effect: Physical presence of objects are not changed, but trigger other events.

  4. Three Phases of Collision Resolution • Prologue: A collision is known to happen. Signal objects that involve in the collision through event triggers. • Collision: A collision happens; what actions should be applied to colliding objects, i.e., stop moving. • Epilogue: Propagate post-collision effect, i.e., destroy objects, deform objects, and play sound.

  5. Brief Review of Collision Detection • Overlap Testing: -- If there is an overlap, use bisection method to detect the position of collision. -- Collision position usually can be found within 5 iterations. -- May fail when objects move too fast. • Intersection Testing: --Testing the geometry of object swept against other objects swept. -- More computation efficient and can predict collision. -- Not applicable to network games and complex physics effect.

  6. Resolution of Overlap Testing • Extract the collision normal. • Extract the penetration depth. • Make penetration depth be 0. • Compute new velocities. • Apply post-collision effect.

  7. Demo of Overlap Testing 1 2 * Step 2 won’t be seen; the collision was solved before being rendered.

  8. Resolution of Intersection Testing • Pre-computation ensures no overlap. • Extract normal. • Compute new velocities. • Apply post-collision effect.

  9. Demo of Intersection Resolution * Collision position can be pre-determined.

  10. Further Readings • 1. Collision Detection: http://www.harveycartel.org/metanet/tutorials/tutorialA.html • 2.Collision Detection and resolution: http://www.peroxide.dk/download/tutorials/tut10/pxdtut10.ht • 3. A demo of collision detection: http://robotduck.com/content/articles/director/collision/getPixel/

  11. Collision Resolution Demo with OpenGL • 1. Collision with no resolution. • 2. Trigger events (prologue) • 3. Collision occurs (collision) • 4. Apply new velocity (epilogue) • 5. Apply post-collision effect (epilogue)

  12. Questions? Thank You!

More Related