To build the project, run the following commands:
$ git clone https://github.com/Jragoon/Raytracer
$ cd Raytracer
$ mkdir build
$ cmake ..
$ make
Then, run the Raytracer to generate the image:
./Raytracer
The result will be a file called output.ppm in the same directory.
Spheres with a fully reflective mirror material.
To darken the areas where we want to create shadows, we have to imagine another line- this time originiating from our hit point. From the hit point, we need to draw a line to the light source. If we run into another object, then we know that we are in the shadow of another object. Therefore, we can skip the normal illumination sequence for this point in the framebuffer.
Specular lighting is responsible for creating the effect of a shiny surface. Essentially, the brighter the spot on our object, the more aligned the reflected light direction and surface normal. The formula used for determining the reflection direction is derived from the law of reflection.
When we shoot our rays from the origin out into our scene and we make contact with an object- how do we determine the color of the pixel at this location? First, we get the sphere's raw color (for us, we store that in a 3D Vector representing RGB). Then, to illuminate the point, we need to figure out two things: the direction of our light source and the surface normal. The total brightness of this spot can be determined by finding the dot product between the normalized direction of the light and the surface normal of our object. The more aligned these two vectors are, the more this point is directly facing the light.
Once we have the dot product of these two vectors, we scale it by the intensity of our light source. Then, once we have our scaled value, we use it to scale the original color of the object at this point. Doing this will scale the color values of our object to a higher number. When discussing RGB color values, higher numbers represent brighter colors. For example, (0, 0, 0) would represent black while (1, 1, 1) would represent white.
Credit for describing Ray Tracer behavior, knowledge: https://www.scratchapixel.com/lessons/3d-basic-rendering/introduction-to-ray-tracing