1. Multiple-pass Reflection Depth of Field
Assignment 2

2. Assignment 2 DeadLine: 12/18 23:59 Multiple-pass Reflection
Depth of Field

3. Assignment 2
It is not necessary to follow TAs implementation rule/steps.
It is free if it comes up the same result.
Do Not Copy
We ‘ll announce Demo after deadline.

4. Assignment 2

5. System Setting Main Function
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGBA | GLUT_DEPTH | GLUT_STENCIL);

6. System Setting Display Function glEnable(GL_STENCIL_TEST);
glClearStencil(initial_value);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT | GL_ACCUM_BUFFER_BIT);

7. Multiple-pass Reflection – Mirror Data
Front Mirror Reflection
position is (-40, 20, 0)
parallel to yz-plane.
Back Mirror Reflection
position is (40, 20, 0)
parallel to yz-plane

8. Multiple-pass Reflection - Step
Set Stencil Buffer value
Use “glColorMask before” / “glClear after” drawing make it non-visible
Not visible
Draw Scene
In each case(value),draw the “Right” Scene

9. Stencil Buffer - Reflection
glCullFace(GLenum mode);
Default = GL_BACK
Doing back-face culling
Drawing Reflection of Scene,we only take the BACK-FACE part.
Doing front-face culling

10. Set Stencil Buffer value - Initial Value

11. Set Stencil Buffer value - Setting Mirror
glStencilFunc(GL_ALWAYS, 1, 0xFF);
glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
drawMirror()

12. Set Stencil Buffer value - Mirror Value

13. Set Stencil Buffer value – Setting Scene
glStencilFunc(GL_EQUAL, 1, 0xFF);
glStencilOp(GL_KEEP, GL_KEEP, GL_DECR);
drawScene()
//The part closer to Camera than Mirror

14. Set Stencil Buffer value - Final Value

15. Stencil Buffer – Draw Scene
glStencilFunc(GL_EQUAL, 0, 0xFF);
glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
drawScene()
//The part closer to Camera than Mirror

16. Stencil Buffer – Draw Scene
glStencilFunc(GL_EQUAL, 1, 0xFF);
glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
drawScene()
1st Reflection in the Mirror

17. Depth Of Field gluLookAt( eyes, target, up )
Combine the result with Accumulation Buffer
gluLookAt( eyes + jitter, object, up )

18. Depth Of Field (II)
首先，用眼睛的位置減去物件的位置，算出一個向量。再用這個向量跟 up去做 cross，算出 right 向量。用 right 向量跟 up 向量的單位向量算出位移 (as a circle)，最後用 accumulation combine result

19. Depth of Field (III) 算出 新的 座標系 (forward, right, up) For i = [ 0 : N)
用 right & up 算出 jitter 的新位置
( jitter = right * cosine + up * sine )
glEnable(GL_MODELVIEW)
glLoadIdentity()
glLookAt()
(draw your scene)
glAccum( i ? GL_ACCUM : GL_LOAD, 1.0 / N);
glAccum(GL_RETURN, 1.0)

20. Assignment Request Mobile Camera Multi-pass Reflection Depth of Field
At least 4 passes each mirror
Depth of Field
Render Normally