From 87ba3b4cf459b386739304e825cd78e052efee37 Mon Sep 17 00:00:00 2001 From: Michael Zhang Date: Fri, 17 Feb 2023 03:07:11 -0600 Subject: [PATCH] Finish writeup --- assignment-1b/writeup.md | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/assignment-1b/writeup.md b/assignment-1b/writeup.md index c9aaf07..17d375a 100644 --- a/assignment-1b/writeup.md +++ b/assignment-1b/writeup.md @@ -57,14 +57,24 @@ decreases in brightness when all other factors remain constant. ## Varying $k_d$ -TODO +$k_d$ is the strength of the diffuse component. It also affects an object's +diffuse color, but at a strength that's affected by how much of it faces the +light. Much like the dark side of the moon, the parts of the object that aren't +pointed at the light will not receive as much of the light's influence. In the +image below, I varied $k_d$ between 0.2 and 1. Note how the part pointed to the +light changes the strength of the brightness as all other factors remain +constant. ![Varying $k_d$](examples/kd-demo.png){width=360px} \ ## Varying $k_s$ -TODO +$k_s$ is the specular strength. It uses the object's specular color, which is +like its reflective component. When there is a large specular $k_s$, there's a +shine that appears on the object with a greater intensity. In the image below, I +varied $k_s$ between 0.2 and 1. Note how the whiteness of the light is more +reflective in higher $k_s$ values as other factors remain constant. ![Varying $k_s$](examples/ks-demo.png){width=360px} \ @@ -74,7 +84,8 @@ TODO $n$ is the exponent saying how big the radius of the specular highlight should be. In the equation, increasing the exponent usually leads to smaller shines. In the image below, I varied $n$ between 2 and 100. Note how the size of the shine -is more focused but covers a smaller area as $n$ increases. +is the same intensity, but more focused but covers a smaller area as $n$ +increases. ![Varying $n$](examples/n-demo.png){width=360px} \ @@ -142,9 +153,21 @@ are away from the eye. ## Shortcomings of the model -The model cannot be used to represent TODO +The Phong formula is just a model of how light works, and doesn't actually +represent reality. There's not actually rays physically escaping our eyes and +hitting objects; it's actually the other way around, but computing it that way +would not be efficient since we would be factoring in a lot of rays that don't +ever get rendered. + +Also, one needs to take care to use reasonable constants. For example, if using +a different specular light color than the diffuse color, then it may produce +some bizarre lighting effects that may not actually look right compare to +reality. # Arbitrary Objects +Here is an example scene with some objects that demonstrates some of the +features of the raytracer. + ![Objects in the scene](examples/objects.png){width=360px} \