1 / 17

GPU- Based Responsive Grass

GPU- Based Responsive Grass. Jens Orthmann, Christof Rezk-Salama, Andreas Kolb. Overview. Motivation Grass Representation Collision Handling Rendering Results Future Work. Motivation. Physically correct reacting environment improves immersion for players

miranda-sweet
Download Presentation

GPU- Based Responsive Grass

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. GPU-BasedResponsive Grass JensOrthmann, Christof Rezk-Salama, Andreas Kolb

  2. Overview • Motivation • Grass Representation • Collision Handling • Rendering • Results • Future Work

  3. Motivation • Physically correct reacting environment improves immersion for players • Until now: research has been focused on the animation and rendering • Modern graphics cards  shift the workload to the GPU

  4. Grass Billboards • Usually: Clumps of grass are approximated by billboards quad with a semi-transparent texture • Crossed billboards produce a more volumetric impression

  5. CPU-BasedPredecision • The grass layer is organized in an octree • A lookup into the octree brings up colliding nodes • Affected billboards will be handled on the GPU

  6. GPU-BasedCollisionhandling • Collision detection and reaction requires a more detailed mesh • Collisions are detected and resolved per vertex • Mass-spring system preserves the shape • Performance stability via recovering Animation + Refinement Collision- detection Collision- reaction Recovering Simplification

  7. Depth Cubes • Objects are implictly represented by depth-cubes • The mesh is projected to each face • Each face stores the distance to the surface and the normal information

  8. CollisionDetection • Vertex collides if it is occluded by all six faces of the depth cube • Occlusion is determined by a lookup within the depth cube • The accuracy of the detection depends on the resolution of the depth cube

  9. CollisionReaction • The normal vector within the depth cube defines the reaction‘s direction • The vertex then is moved along the normal out of the object • As each vertex is handled separately unrealistic distortions may occur

  10. Shape Preservation • Spring model preserves the overall shape • Topology information is required • Length constraints correct adjacent vertices

  11. Recovering • Previously collided billboards will regenerate • Interpolation between deformed and undeformed shape • Billboards will be simplified after regeneration undeformed deformed

  12. Irradiance Information • Ambient occlusion: How much light reaches a point and from which direction? • Amount and mean-direction are determined by using shadow maps • Sampling an environment map results in the irradiance

  13. Rendering • Irradiance information is precomputed for the complete grass layer • During runtime: tri-linear interpolation within the volume results in the irradiance

  14. Alpha-To-Coverage • The transparency of a pixel determines how much sub-samples are colored • The final color is calculated during the multi-sample resolve phase • Quality depends on the multi-sampling resolution

  15. Results Video

  16. Future Work • Take dynamic environments one step further • Enables integration of new game elements and extends game logics • Apply responsive grass algorithm to small plants like bushes, shrubs… • Improvement of visual results by dynamic sub-divisions

  17. ThankYou • Thank you for your attention

More Related