1. Penumbra Maps: Approximate Soft Shadows in Real-Time Chris Wyman and Charles Hansen University of Utah Speaker: Alvin Date: 9/29/2003 EUROGRAPH 2003

2. Alivn/GAME LAB/CSIE/NDHU Penumbra Maps: Approximate Soft Shadows in Real-Time2 Outline Introduction Introduction Penumbra Map Penumbra Map Discussion Discussion Result Result Conclusions and Future Works Conclusions and Future Works

3. Alivn/GAME LAB/CSIE/NDHU Penumbra Maps: Approximate Soft Shadows in Real-Time3 Introduction Shadow Map + Penumbra Map Shadow Map + Penumbra Map Three-pass process Three-pass process Renders a standard shadow map. Renders a standard shadow map. Renders the penumbra map. Renders the penumbra map. Renders the final image. Renders the final image. Penumbra Map = Light Intensity Map Penumbra Map = Light Intensity Map

4. Alivn/GAME LAB/CSIE/NDHU Penumbra Maps: Approximate Soft Shadows in Real-Time4 Introduction Shadow Map (left) and Penumbra Map (right).

5. Alivn/GAME LAB/CSIE/NDHU Penumbra Maps: Approximate Soft Shadows in Real-Time5 Penumbra Map Input: (See from the light center) Input: (See from the light center) A standard shadow map. A standard shadow map. Silhouette vertices and edges. Silhouette vertices and edges. Use Haines ’ shadow plateaus. Use Haines ’ shadow plateaus.

6. Alivn/GAME LAB/CSIE/NDHU Penumbra Maps: Approximate Soft Shadows in Real-Time6 Penumbra Cone & Sheet

7. Alivn/GAME LAB/CSIE/NDHU Penumbra Maps: Approximate Soft Shadows in Real-Time7 Fragment (Bernstein interpolant)

8. Alivn/GAME LAB/CSIE/NDHU Penumbra Maps: Approximate Soft Shadows in Real-Time8 Discussion Overlapping penumbra. Overlapping penumbra. As an area light increases in size, silhouettes vary more over the light so the generated shadows will become less realistic. As an area light increases in size, silhouettes vary more over the light so the generated shadows will become less realistic. As a shadow ’ s umbra size shrinks, there are noticeably larger, darker shadows. As a shadow ’ s umbra size shrinks, there are noticeably larger, darker shadows.

9. Alivn/GAME LAB/CSIE/NDHU Penumbra Maps: Approximate Soft Shadows in Real-Time9 Overlapping Penumbra

10. Alivn/GAME LAB/CSIE/NDHU Penumbra Maps: Approximate Soft Shadows in Real-Time10 Result

11. Alivn/GAME LAB/CSIE/NDHU Penumbra Maps: Approximate Soft Shadows in Real-Time11 Result

12. Alivn/GAME LAB/CSIE/NDHU Penumbra Maps: Approximate Soft Shadows in Real-Time12 Result

13. Alivn/GAME LAB/CSIE/NDHU Penumbra Maps: Approximate Soft Shadows in Real-Time13 Conclusions and Future Works Rendering approximate soft shadows in real-time. Rendering approximate soft shadows in real-time. Allow dynamical models to cast soft shadows. Allow dynamical models to cast soft shadows. Approximate a full penumbra using vertex programs to adjust the silhouette edge points. Approximate a full penumbra using vertex programs to adjust the silhouette edge points. Implement in hardware. Implement in hardware.