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Project 6: Deferred Shader ------------------------------------------------------------------------------- Fall 2013 -------------------------------------------------------------------------------

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INTRODUCTION: ------------------------------------------------------------------------------- In this project, I was introduced to the basics of deferred shading. I wrote GLSL and OpenGL code to perform various tasks in a deferred lighting pipeline such as creating and writing to a G-Buffer.

The features I implemented include toon shading, bloom effect, screen space ambient occlusion, and point lights.

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RENDERS: -------------------------------------------------------------------------------

Here are some screenshots:


diffuse with point light sources


bloom effect


toon effect


screen space ambient occlusion


screen space ambient occlusion


depth mode


normals mode


color mode


screen space position mode

Here's a video: http://www.youtube.com/watch?v=LJ39Sb76KdU

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PERFORMANCE REPORT: -------------------------------------------------------------------------------

A performance analysis on how the number of point lights affects the frame rate.

Number of Lights	Frames per Second
1	~60 fps
8	~60 fps
27	~60 fps
64	~60 fps
125	~60 fps
216	~34 fps
343	~23 fps
512	~18 fps
729	~15 fps
1000	~13 fps
1331	~12 fps
1728	~12 fps
2197	~12 fps
2744	~12 fps

Because there's the frame rate is capped to the 60 fps refresh rate of my computer's display, it's not surprising that the first 5 entires are all around 60 fps. However, what seems to be interesting is that once the number of points lights reaches a certain number, the frame rate doesn't drop off anymore.

Despite the fact that my backface culling was a naive implementation, it still succeeded in speeding up my code. With the ability to ignore faces that weren't facing the camera, my rasterizer was able to show a rather decent speed up in the amount of time it took to compute and rasterize each frame.