An Algorithm of Eye-Based Ray Tracing on MATLAB Instructor: Prof.Emery Group Members: Xingjian Yang Zhengqi Long Haonan Peng

1. Introduction 1. 1 Ray Tracing Ray tracing is a special rendering algorithm in 3D computer graphics.

V.S 1. Introduction 1. 2 Ray Tracing Method Eye-based Ray Tracing Light-based Ray tracing All the light computed is significant for the image plane. Most of the light contribute very less to image plane. Not very good for diffuse light. Very good for diffuse light. Computational efficient. Relatively inefficient. V.S

How do every element in the environment contribute on the image plane? 1. Introduction 1. 3 Basic Idea How do every element in the environment contribute on the image plane?

2. Illumination model 2. 1 Basic models 1. Light source Choose point light as the light source. Point light: light rays shine out in a spherical manner from a center point.(In real world, like a light bulb or a candle flame) 2. RGB color model This model is an additive color model that adds red, green and blue light together to produce other colors. 3. Simple illumination model: Phong model

Ambient light → sampling rays 2. Illumination model 2. 2 Phong model and modifications Ambient light: represents the effect that one object has on another one. Ambient light → sampling rays Effect of ambient light

2. Illumination model 2. 2 Phong model and modifications Resulting set of equations: Diffuse reflection Non-ideal specular reflection Parameters set for each surface: Kdr, Kdg, Kdb, Ks and ns.

2. Illumination model 2. 3 The result of parameter change Change Kd components and we can change the color of a surface:

2. Illumination model 2. 3 The result of parameter change Increase Ks and we can make the surface look more smooth:

2. Illumination model 2. 3 The result of parameter change Increase ns and we can make the surface look more shiny:

3. Rendering 3.1 scene setting & sphere definition

3. Rendering 3.1 scene setting & sphere definition

3. Rendering 3.1 scene setting & sphere definition

3. Rendering 3.2 camera and image plane setting

3. Rendering 3.3 First-order rendering

3. Rendering 3.4 second-order rendering

3. Rendering 3.5 refraction rendering

4. Conlusion and Discussion 4. 1 Conclusion The order 1 algorithm gives basic light response of the image point, works well for rough surface and smooth surface. The order 2 algorithm gives light response for reflection light and diffuse light for non-transparent surface, and refraction light for transparent surface. By combining order 1 and order 2 with proper percent, we can deal with partial smooth partial rough surface, as well as partial transparent surface. The diffuse hemisphere is an efficient way to calculate to estimate the diffuse light effect of the pixel on image plane. This algorithm is suitable for most of environment compared with other current light rendering technology

4. Conlusion and Discussion Need to use matrix calculation to replace for loops. Some parts of the rendering picture need denoising. Can not deal with multiple specular reflection.

Instructor: Prof.Emery Xingjian Yang Zhengqi Long Haonan Peng An Algorithm of Eye-Based Ray Tracing on MATLAB ME 535 Project Thank you ! Instructor: Prof.Emery Group Members: Xingjian Yang Zhengqi Long Haonan Peng