====== Seminars ======

===== Syllabus =====
^ Week ^ Date ^ Content ^
| 1. |  1.10. | //[[https://cent.felk.cvut.cz/courses/APG/PDF/seminar/apg0.pdf|Introduction]]// |
| 2. |  8.10. | Team forming \\ //[[https://cent.felk.cvut.cz/courses/APG/PDF/seminar/apg1.pdf|Homework assignment I]]// |
| 3. |  15.10. | Homework assignment I - consultation \\ |
| 4. |  22.10. | Homework assignment I - submission \\ //[[https://cent.felk.cvut.cz/courses/APG/PDF/seminar/apg2.pdf|Homework assignment II]]// |
| 5. |  29.10. | Homework assignment II consultation |
| 6. |  5.11. | Homework assignment II - submission \\ //[[https://cent.felk.cvut.cz/courses/APG/PDF/seminar/apg3.pdf|Homework assignment III]]// |
| 7. |  12.11. | Homework assignment III - consultation |
| 8. |  19.11. | Homework assignment III - submission \\ //[[https://cent.felk.cvut.cz/courses/APG/PDF/seminar/apg4.pdf|Homework assignment IV]]// |
| 9. |  26.11. | Homework assignment IV - consultation |
| 10. |  3.12. | Homework assignment IV - submission \\ //[[https://cent.felk.cvut.cz/courses/APG/PDF/seminar/apg5.pdf|Homework assignment V]]// |
| 11. |  10.12. | Test \\ Homework assignment V - consultation |
| 12. |  17.12. | Homework assignment V - submission |
| 13. |  7.1. | Assessment |

===== Rules of the Game =====
  * [[http://dcgi.felk.cvut.cz/en/study/academic_principles|Academic principles ]]
  * 5 homework assignments: 50 points (10 points each) + bonus points
    * All assignments must be accepted
    * Later submissions are penalized by 3 points for each week of delay!
  * Test in the 11th week for up to 10 points
  * At least 30 points for the assessment

===== Homework Assignments =====
  * Simple graphics library (SGL) divided into 5 assignments
  * Team of two people
  * Submission:
    * Manual evaluation: https://cw.felk.cvut.cz/brute/
      * Clear code, comments, etc.
      * Functionality
    * Automatic evaluation: https://apg.courses.dcgi.fel.cvut.cz/
      * Images diff
      * Speed competition
  * Speed competition (homework assignments I, II, III):
    * 3 bonus points for the 1st fastest solution
    * 2 bonus points for the 2nd fastest solution
    * 1 bonus point for the 3rd fastest solution

==== Test Application ====
  * Test application using GLUT for all homework assignments: [[https://cent.felk.cvut.cz/courses/APG/testapp.zip|testapp.zip]]
    * Use CMake to generate makefile or VS solution 
    * Windows: freeglut binaries are part of the zip file
    * Linux/MacOS: GLUT installation (e.g. freeglut using brew)
  * Test application calls SGL functions defined in sgl/sgl.h, so don't change it!
  * Implement functions in sgl/sgl.cpp
  * Add your h/cpp files to sgl/
  * Switch contexts using keys 0-9
  * [[https://cent.felk.cvut.cz/courses/APG/testappdoc/html/sgl_8h.html|SGL API documentation]]

==== Homework Assignment I ====
=== 2D Graphics Library, part A ===
[[https://cent.felk.cvut.cz/courses/APG/PDF/seminar/apg1.pdf|Presentation]]
  * Library initialization, data structures design
  * Rasterization of basic primitives:
    * Point
    * Line and polyline (Bresenham's algorithm)
    * Circle (Bresenham's algorithm)
    * Ellipse (sglEllipse) and arc (sglArc):
      * Approximation of ellipse by 40 line segments
      * Approximation of arc by 40*(from-to)/(2 PI) line segments
      * BONUS:
        * Adaptive approximation of ellipse and arc with the error less than 1 pixel (1 point)
  * Transformations:
    * Modeling transformations (translation, rotation, scale)
    * Orthographic projection (sglOrtho)
    * Viewport transformation
    * Transformation stack

=== Reference Images ===
graphics elements\\ {{https://cent.felk.cvut.cz/courses/APG/results/test1a-ref.png?200x150|graphics elements}}

transformations\\ {{https://cent.felk.cvut.cz/courses/APG/results/test1b-ref.png?200x150|transformations}}

transformation stack\\ {{https://cent.felk.cvut.cz/courses/APG/results/test1c-ref.png?200x150|transformation stack}}

==== Homework Assignment II ====
=== 2D Graphics Library, part B ===
[[https://cent.felk.cvut.cz/courses/APG/PDF/seminar/apg2.pdf|Presentation]]
  * Non-convex polygon filling:
    * Polygon definition (sglBegin(SGL_POLYGON))
    * Self-intersecting polygon filling, so don't use seed filling!
  * Filling circle, ellipse, and arc
  * Perspective projection (sglFrustum)
  * Depth management via z-buffer
  * BONUS:
    * [[http://citeseer.ist.psu.edu/viewdoc/summary?doi=10.1.1.3.211|Perspective correct interpolation of vertex attributes]] (1 point)

=== Reference Images ===
non-convex polygon filling\\ {{https://cent.felk.cvut.cz/courses/APG/results/test2a-ref.png?200x150|non-convex polygon filling}}

graphics elements filling\\ {{https://cent.felk.cvut.cz/courses/APG/results/test2b-ref.png?200x150|graphics elements filling}}

3D scene rendering - cube with z-buffer enabled/disabled\\ {{https://cent.felk.cvut.cz/courses/APG/results/test2c-ref.png?200x150|3D scene rendering - cube with z-buffer enabled/disabled}}

3D scene rendering - NFF file\\ {{https://cent.felk.cvut.cz/courses/APG/results/test2d-ref.png?200x150|3D scene rendering - NFF file}}

==== Homework Assignment III ====
=== Simple Ray Tracer, part A ===
[[https://cent.felk.cvut.cz/courses/APG/PDF/seminar/apg3.pdf|Presentation]]
  * Scene definition via SGL API (see sgl.h)
  * Primary rays generation:
    * Transformation matrix inverse
    * [[https://cent.felk.cvut.cz/courses/APG/invert-matrix.cpp|Matrix inverse from Numerical Recipes in C]]
  * [[https://cent.felk.cvut.cz/courses/APG/ray-sphere.cpp|Ray-sphere intersection]]
  * Ray-triangle intersection: [[https://dl.acm.org/citation.cfm?id=272315|Moeller]] or [[https://cent.felk.cvut.cz/courses/APG/triangle-pbrt.cpp|PBRT]]
  * Phong lighting model:
    * Material definition (see sglMaterial)
    * Diffuse coefficients: [r*kd g*kd b*kd]
    * Specular coefficients: [ks ks ks]
  * BONUS:
    * Adaptive anti-aliasing (1 point),
    * Multiple lighting models support: [[http://inst.cs.berkeley.edu/~cs294-13/fa09/lectures/cookpaper.pdf|Cook-Torrance]] or [[http://www.graphics.cornell.edu/pubs/2005/Wal05.html|Ward]] (1 point)

=== Test scenes and reference images ===
sphere ([[https://cent.felk.cvut.cz/courses/APG/test3/nff/sphere.nff|sphere.nff]])\\ {{https://cent.felk.cvut.cz/courses/APG/results/test3a-ref.png?200x200|sphere}}

Cornell box ([[https://cent.felk.cvut.cz/courses/APG/test3/nff/cornell.nff|cornell.nff]])\\ {{https://cent.felk.cvut.cz/courses/APG/results/test3b-ref.png?200x200|Cornell box}}

sphere on floor ([[https://cent.felk.cvut.cz/courses/APG/test3/nff/floor_sph.nff|floor_sph.nff]])\\ {{https://cent.felk.cvut.cz/courses/APG/results/test3c-ref.png?200x200|sphere on floor}}

==== Homework Assignment IV ====
=== Simple Ray Tracer, part B ===
[[https://cent.felk.cvut.cz/courses/APG/PDF/seminar/apg4.pdf|Presentation]]
  * Shadow rays
  * Secondary Rays: recursive ray tracing:
    * Reflections and [[https://cent.felk.cvut.cz/courses/APG/refract.cpp|refractions]]
    * Max. recursion depth 8
  * Backface culling: ignore intersections if DotProd(normal,dir)>0.0
  * BONUS:
    * Depth of field (1 point)

=== Test Scenes and Reference Images ===
shadows ([[https://cent.felk.cvut.cz/courses/APG/test4/nff/cornell-blocks.nff|cornell-blocks.nff]])\\ {{https://cent.felk.cvut.cz/courses/APG/results/test4a-ref.png?200x200|shadows}}

reflections and refractions ([[https://cent.felk.cvut.cz/courses/APG/test4/nff/cornell-spheres.nff|cornell-spheres.nff]])\\ {{https://cent.felk.cvut.cz/courses/APG/results/test4b-ref.png?200x200|reflections and refractions}}

multiple reflections and refractions ([[https://cent.felk.cvut.cz/courses/APG/test4/nff/cornell-spheres-crazy.nff|cornell-spheres-crazy.nff]])\\ {{https://cent.felk.cvut.cz/courses/APG/results/test4c-ref.png?200x200|multiple reflections and refractions}}

==== Homework Assignment V ====
=== Simple Ray Tracer, part C ===
[[https://cent.felk.cvut.cz/courses/APG/PDF/seminar/apg5.pdf|Presentation]]
  * Area light sources:
    * Emissive materials support (see sglEmissiveMaterial)
    * Point sampling on triangles, 16 samples per triangle
    * Intensity of light samples (Phong lighting model):
      * sample_i = (r,g,b)*cos fi*(light_triangle_area/num_samples)/(c0 + c1*d + c2*d^2)
      * cos fi = DotProd(light_triangle_normal, -shadow_ray.direction)
  * Environment mapping:
    * Use environment map instead of constant background color (see sglEnvironmentMap)
    * Mapping ray direction to environment map coordinates (u,v) [0,1]x[0,1]:
      * d = sqrt(dir.x^2 + dir.y^2)
      * r = d>0 ? acos(dir.z)/(2*PI*d) : 0.0
      * u = 0.5 + dir.x * r
      * v = 0.5 + dir.y * r
  * BONUS:
    * Textures support (2 points)

=== Test Scenes and Reference Images ===
area light source ([[https://cent.felk.cvut.cz/courses/APG/test5/nff/cornell-blocks-arealight.nff|cornell-blocks-arealight.nff]])\\ {{https://cent.felk.cvut.cz/courses/APG/results/test5a-ref.png?200x200|area light source}}

color area light source ([[https://cent.felk.cvut.cz/courses/APG/test5/nff/cornell-blocks-arealight-color.nff|cornell-blocks-arealight-color.nff]])\\ {{https://cent.felk.cvut.cz/courses/APG/results/test5b-ref.png?200x200|color area light source}}

environment map St. Peter's Basilica ([[https://cent.felk.cvut.cz/courses/APG/test5/nff/basilica.nff|basilica.nff]]/[[https://cent.felk.cvut.cz/courses/APG/test5/nff/stpeters_probe.hdr|stpeters_probe.hdr]])\\ {{https://cent.felk.cvut.cz/courses/APG/results/test5c-ref.png?200x200|environment map St. Peter's Basilica}}

environment map St. Uffizi Gallery ([[https://cent.felk.cvut.cz/courses/APG/test5/nff/uffizi.nff|uffizi.nff]]/[[https://cent.felk.cvut.cz/courses/APG/test5/nff/uffizi_probe.hdr|uffizi_probe.hdr]])\\ {{https://cent.felk.cvut.cz/courses/APG/results/test5d-ref.png?200x200|environment map St. Uffizi Gallery}}