This work is licensed under a Creative Commons
Attribution-NonCommercial-NoDerivatives 4.0 International License.
(http://creativecommons.org/licenses/by-nc-nd/4.0/)

ECS 175 Fall 2019 - Assignment 5 Manual
Author: lxylxy123456 (https://github.com/lxylxy123456/)

Run
    ./Project5
    OR
    ./Project5 scene_name
    All interactions and feedback are in command line

Screen layout
    The upper-left, upper-right, lower-left screens are the same as project 3
    However, these 3 screens do NOT draw spheres
    The lower-right screen shows the ray-tracing result (this is project 5)
    By default, the camera is looking from (5, 5, 5) to (0, 0, 0)
    By default, the light source is at (0.75, 0.75, 0.75)
    By default, each 5x5 pixel have a ray (to be efficient). To make it 1x1,
     enter "15 1" then press Enter.

Sample scenes
	All pre-rendered images are in "png" folder in the submission zip file.
		For example, "scene4_1.png" and "scene4_2.png" are for "scene4".
    ./Project5 scene0
        This scene is two spheres, where the green one leaves shadow on blue one
        To view at another angle, enter the following line and press Enter
            8    5 7 3    -1 -1.44 -0.57    0 1 0    3    100    0.1
        Due to reflection, the blue sphere may have some "dots". Enter `16 0` to
         remove them.
    ./Project5 scene1
        This scene shows a few object's reflection. The red cube reflects the
         green sphere and blue object. If observing closely, the green sphere
         also reflects the red cube.
    ./Project5 scene2
        After loading, please enter "17" and press Enter (disable shadowing)
        This is a blue cube with a red sphere inside. The blue cube's refraction
         index is 1.3, so the sphere is still visible.
    ./Project5 scene3
        After loading, please enter "17" and press Enter (disable shadowing)
        This is a blue cube with a red sphere inside. The blue cube's refraction
         index is 13000, so the sphere looks like 3 separate spheres.
    ./Project5 scene4
        This scene is some objects, with one small gray square wrapping the
         light source, so all other objects just have ambient light in ray
         tracing model.
        Enter "1 2" and press Enter to hide this gray cube, and all objects
         become visible. (similar to scene1)
    ./Project5 scene5
        After loading the scene, enter the following line and press Enter
            8    1 0 0.5    -1 1 0    0 0 1    30    30    0.1
        The big gray part can be considered a big piece of glass. If we view the
         green sphere behind it, the image shifts than if we do not view it
         through glass. (a basic phenomenon in physics class)
    ./Project5 scene6
        After loading the scene, enter the following line and press Enter
            17    5 11
        The sphere can be thought as a crystal ball, and we are looking at a 
         blue cube through it. 
        To hide the sphere, enter "6 0" and press Enter.
        Use "2 0   .1 0 0" and Enter multiple times to move the cube out

Scene file format
    First line is an integer N, representing number of objects
    Repeat N times:
        For a sphere, the first line is "0"
            Then 3 numbers for center
            Then 1 number for radius
            Then 3 number for diffuse color
            Then 1 integer for specularity
        For a polyhedra, the first line is "1"
            Then an integer V for number of vertices
            Then V lines, each line is 3 numbers for vertex position
            Then V lines, each line is 3 numbers for vertex color
            Then an integer T for number of triangles
            Then T lines, each line is 3 integers for index of triangle's vertex
            Then T lines, each line is specularity of the face
        Regardless polyhedra or sphere:
            Then a number for refraction index
            Then 3 numbers for kr (reflection coefficient)
            Then 3 numbers for kt (refraction coefficient)

Many menu entries are inherited from Project 3, and will not be discussed here.
 Most of these entries are marked with "(Project 3)", and can be ignored.

Menu entry 0
    Quit

Menu entry 1
    Show / hide a polyhedra, use its index in input file (start from 0).

Menu entry 5
    Configure Phong model, with a submenu
    Sub-entry 2, 3, 4, 5, 6, 7: specifying 3D vector or color
    Sub-entry 1, 8, 13: specify a single floating point value
    Sub-entry 9, 10, 11, 12, 14, 15: turn on / off some feature
    Sub-entry 1 and 2 are exclusive. Selecting one will disable the other
        For project 5, please only use sub-entry 2, which specifies the eye
         position for non-ray tracing model explicitly.
    Sub-entry 12 and 13 are exclusive, which defines how to map color after this
     calculation to r, g, b in [0, 1]
        Sub-entry 12 is normalizing all color such that the brightest is 1.
         Sometimes this may make the color unstable when the light changes. 
        Sub-entry 13 is multiplying all color by a constant, and force colors
         larger than 1 to be 1. In this method, some thing may be too bright or
         too dark, then you can look at output of Sub-entry 12 and decide a
         reference constant. The defult behavior has the constant value of 100. 
    Sub-entry 14 and 15 turns on / off reflection & refraction for all objects.
        To configure each object, edit input file. 

Menu entry 6
    Show / hide a sphere, use its index in input file (start from 0).

Menu entry 8
    This entry changes the camera viewing model's parameters
    Follow command line prompt, specify f, a, u, alpha, ze max, ze min

Menu entry 15
    Specifies an integer for resolution of ray tracing. Default is 5, which
     means for each 5x5 pixel group, a ray is calculated. Minimum is 1.

Menu entry 16
    Specifies level of recursion of ray tracing. Default is 3. 

Menu entry 17
    If shadow feelers are enabled, the program will determine whether it
     receives direct light from a light source or not. If not, it will only
     calculate ambient light. 

Animation
    ./anime_camera.py scene0
    Also try to use scene1, scene5, scene6
    For pre-rendered results, see files in "gif" folder