Add more to writeup

assignment-1b/.gitignore

@@ -7,3 +7,4 @@
 *.pdf
 perf.data*
 flamegraph.svg
+showcase.png

assignment-1b/Makefile

@@ -7,9 +7,10 @@ ZIP := zip
 PANDOC := pandoc
 CONVERT := convert
 
-HANDIN := hw1b.michael.zhang.zip
+HANDIN := ./hw1b.michael.zhang.zip
 BINARY := ./raytracer1b
-WRITEUP := writeup.pdf
+WRITEUP := ./writeup.pdf
+SHOWCASE := ./showcase.png
 SOURCES := Cargo.toml $(shell find -name "*.rs")
 
 EXAMPLES := $(shell find examples -name "*.txt")
@@ -31,9 +32,12 @@ $(BINARY): $(SOURCES)
 		cargo build --profile release-handin
 	mv target/docker/release-handin/raytracer1b $@
 
-$(HANDIN): $(BINARY) $(WRITEUP) Makefile Cargo.toml Cargo.lock README.md $(EXAMPLES_PNG) $(EXAMPLES_PPM)
+$(HANDIN): $(BINARY) $(WRITEUP) Makefile Cargo.toml Cargo.lock README.md $(EXAMPLES_PNG) $(EXAMPLES_PPM) $(SHOWCASE)
 	$(ZIP) -r $@ src examples $^
 
+$(SHOWCASE): examples/soft-shadow-demo.png
+	cp $< $@
+
 examples/%.ppm: examples/%.txt $(SOURCES)
 	cargo run --release -- -o $@ $<
 
@@ -44,4 +48,6 @@ writeup.pdf: writeup.md $(EXAMPLES_PNG)
 	$(PANDOC) -o $@ $<
 
 clean:
-	rm -f $(HANDIN) $(BINARY) $(WRITEUP) $(EXAMPLES_PPM) $(EXAMPLES_PNG)
+	rm -rf target/docker \
+		$(HANDIN) $(BINARY) $(WRITEUP) $(SHOWCASE) \
+		$(EXAMPLES_PPM) $(EXAMPLES_PNG)

assignment-1b/README.md

@@ -14,6 +14,10 @@ sources, and the ppm files are the corresponding outputs. They have been
 generated by running this program. For convenience, pngs have also been provided
 using imagemagick.
 
+## Showcase image
+
+The showcase image can be found at `/showcase.png`.
+
 ## Building from source
 
 The Makefile currently uses Docker to produce a more consistent build. If you

assignment-1b/examples/depth-cueing-demo.txt

@@ -0,0 +1,15 @@
+imsize 640 480
+eye -2.5 2 -5
+viewdir -0.2 0 -1
+hfov 90
+updir 0 1 0
+bkgcolor 0.4 0.4 0.4
+
+depthcueing 0.4 0.4 0.4 1 0.1 60 0
+light 0 5 -7.5 1 1 1 1
+
+mtlcolor 1 0.8 0.7 1 1 1 0.6 0.6 0 10
+sphere -5 2 -10 2
+sphere -3 2 -20 2
+sphere 1.5 2 -30 2
+sphere 13 2 -60 2

assignment-1b/examples/ka-demo.txt

@@ -3,21 +3,21 @@ eye 0 0 15
 viewdir 0 0 -1
 hfov 90
 updir 0 1 0
-bkgcolor 0.1 0.1 0.1
+bkgcolor 0.4 0.4 0.4
 
-light 0 3 3 0 0.3 0.3 0.4
+light 0 5 5 1 0.7 0.7 0.8
 
-mtlcolor 0 1 0 1 1 1 0 0.4 0 1
+mtlcolor 0.6 1 0.4 1 1 1 0 0.4 0 1 
 sphere -10 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.2 0.4 0 1
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.4 0 1 
 sphere -5 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.4 0.4 0 1
+mtlcolor 0.6 1 0.4 1 1 1 0.4 0.4 0 1 
 sphere 0 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.6 0.4 0 1
+mtlcolor 0.6 1 0.4 1 1 1 0.6 0.4 0 1 
 sphere 5 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.8 0.4 0 1
+mtlcolor 0.6 1 0.4 1 1 1 0.8 0.4 0 1 
 sphere 10 0 0 2

assignment-1b/examples/kd-demo.txt

@@ -3,21 +3,21 @@ eye 0 0 15
 viewdir 0 0 -1
 hfov 90
 updir 0 1 0
-bkgcolor 0.1 0.1 0.1
+bkgcolor 0.4 0.4 0.4
 
-light 0 3 3 0 0.3 0.3 0.4
+light 0 5 5 1 0.7 0.7 0.8
 
-mtlcolor 0 1 0 1 1 1 0.2 0 0 1
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0 0 1
 sphere -10 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.2 0.2 0 1
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.2 0 1
 sphere -5 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.2 0.4 0 1
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.4 0 1
 sphere 0 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.2 0.6 0 1
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.6 0 1
 sphere 5 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.2 0.8 0 1
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.8 0 1
 sphere 10 0 0 2

assignment-1b/examples/ks-demo.txt

@@ -3,21 +3,21 @@ eye 0 0 15
 viewdir 0 0 -1
 hfov 90
 updir 0 1 0
-bkgcolor 0.1 0.1 0.1
+bkgcolor 0.4 0.4 0.4
 
-light 0 3 3 0 0.3 0.3 0.4
+light 0 5 5 1 0.7 0.7 0.8
 
-mtlcolor 0 1 0 1 1 1 0.1 0.2 0 15
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.2 0 15
 sphere -10 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.1 0.2 0.2 15
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.2 0.2 15
 sphere -5 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.1 0.2 0.4 15
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.2 0.4 15
 sphere 0 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.1 0.2 0.6 15
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.2 0.6 15
 sphere 5 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.1 0.2 0.8 15
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.2 0.8 15
 sphere 10 0 0 2

assignment-1b/examples/multiple-lights-demo.txt

@@ -0,0 +1,16 @@
+imsize 640 480
+eye 0 0 -2
+viewdir 0 0 -1
+hfov 90
+updir 0 1 0
+bkgcolor 0.4 0.4 0.4
+
+light -5 5 -7.5 1 1 1 1
+light 5 5 -7.5 1 1 1 1
+
+mtlcolor 0.4 0.6 1 1 1 1 0.2 0.6 0 10
+sphere 0 -2 -10 2
+
+mtlcolor 0.8 0.4 0.4 1 1 1 0.2 0.6 0 10
+sphere -2.5 2.5 -10 1
+sphere 2.5 2.5 -10 1

assignment-1b/examples/n-demo.txt

@@ -3,21 +3,21 @@ eye 0 0 15
 viewdir 0 0 -1
 hfov 90
 updir 0 1 0
-bkgcolor 0.1 0.1 0.1
+bkgcolor 0.4 0.4 0.4
 
-light 0 3 3 0 0.3 0.3 0.4
+light 0 5 5 1 0.7 0.7 0.8
 
-mtlcolor 0 1 0 1 1 1 0.1 0.2 0.4 2
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.2 0.4 2
 sphere -10 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.1 0.2 0.4 6
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.2 0.4 6
 sphere -5 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.1 0.2 0.4 10
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.2 0.4 10
 sphere 0 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.1 0.2 0.4 50
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.2 0.4 50
 sphere 5 0 0 2
 
-mtlcolor 0 1 0 1 1 1 0.1 0.2 0.4 100
+mtlcolor 0.6 1 0.4 1 1 1 0.2 0.2 0.4 100
 sphere 10 0 0 2

assignment-1b/examples/objects.txt

@@ -1,37 +1,37 @@
-imsize 640 480
+imsize 1920 1080
 eye 0 0 15
 viewdir 0 0 -1
 hfov 60
 updir 0 1 0
-bkgcolor 0.1 0.1 0.1
+bkgcolor 0.4 0.4 0.4
 
-depthcueing 0.1 0.1 0.1 1 0.2 100 0
+depthcueing 0.4 0.4 0.4 1 0.1 60 0
 
 light -10 10 -3 0 0.8 0.8 0.8
 light -10 10 -3 1 0.8 0.8 0.8
 
-mtlcolor 0 0.5 0.5 1 1 1 0.2 0.4 0 10
+mtlcolor 0 0.5 0.5 1 1 1 0.2 0.7 0.2 10
 sphere -1 -2 -5 2
-sphere 3 -5 -1 0.5
+sphere 10 -10 -40 1
 
-mtlcolor 0.5 0.5 1 0.4 0.4 0.4 0.2 0.4 0 10
+mtlcolor 0.5 0.5 1 0.4 0.4 0.4 0.2 0.7 0.4 10
 sphere 1 2 -3 3
 sphere -6 3 -4 1
 
-mtlcolor 1.0 0 0.5 0.6 0.4 0.2 0.2 0.4 0 10
+mtlcolor 1.0 0 0.5 0.6 0.4 0.2 0.2 0.6 0.8 10
 sphere 20 20 -50 6
 
-mtlcolor 0.5 0 0.5 0.6 0.4 0.2 0.2 0.4 0 10
+mtlcolor 0.5 0 0.5 0.6 0.4 0.2 0.2 0.5 0 10
 sphere -6 -4 -8 7
 
-mtlcolor 0.8 0 0.3 0.6 0.4 0.2 0.2 0.4 0 10
+mtlcolor 0.8 0 0.3 0.6 0.4 0.2 0.2 0.4 0.2 10
 cylinder -2 2 -3 0 0 5 1 4
 
-mtlcolor 0.8 0.8 0.3 0.6 0.4 0.2 0.2 0.4 0 10
+mtlcolor 0.8 0.8 0.3 0.6 0.4 0.2 0.2 0.8 0.2 10
 sphere -40 35 -80 7
 sphere -25 20 -60 5
 sphere -12.5 15 -40 3
-sphere -6 11 -20 1.5
+sphere -7 14 -30 2
 
 mtlcolor 0.5 1 0.5 0.2 0.4 0.8 0.2 0.4 0 10
 cylinder 5 1 -2 1 -2 1 1 2

assignment-1b/examples/soft-shadow-demo.txt

@@ -4,15 +4,16 @@ viewdir 0 0 -1
 hfov 60
 updir 0 1 0
 bkgcolor 0.5 0.5 0.5
-depthcueing 0.5 0.5 0.5 1 0.4 40 20
+
+depthcueing 0.5 0.5 0.5 1 0.4 60 0
 
 light 10 10 -10 1 1 1 1
 
-mtlcolor 0.5 1 0.5 1 1 1 0.2 1 0 10
+mtlcolor 0.5 1 0.5 1 1 1 0.2 1 0.1 5
-sphere 5 5 -20 5
+sphere 4.5 4.5 -20 4.5
-sphere -5 -5 -20 5
+sphere -4.5 -4.5 -20 4.5
 
-mtlcolor 1 0.5 0.5 1 1 1 0.2 1 0 10
+mtlcolor 1 0.5 0.5 1 1 1 0.2 0.8 0 5
 sphere -10 0 -30 4
 sphere -20 0 -30 4
 sphere -30 0 -30 4

assignment-1b/src/scene/sphere.rs

@@ -4,7 +4,7 @@ use ordered_float::NotNan;
 
 use crate::{ray::Ray, utils::min_f64};
 
-use super::{illumination::IntersectionContext};
+use super::illumination::IntersectionContext;
 
 #[derive(Debug)]
 pub struct Sphere {
@@ -21,9 +21,7 @@ impl Sphere {
     &self,
     ray: &Ray,
   ) -> Result<Option<IntersectionContext>> {
-    let a = ray.direction.x.powi(2)
+    let a = ray.direction.norm();
-      + ray.direction.y.powi(2)
-      + ray.direction.z.powi(2);
     let b = 2.0
       * (ray.direction.x * (ray.origin.x - self.center.x)
         + ray.direction.y * (ray.origin.y - self.center.y)

assignment-1b/src/utils.rs

@@ -3,6 +3,7 @@ use nalgebra::{Matrix3, Vector3};
 use ordered_float::NotNan;
 
 /// Finds the minimum of an iterator of f64s, ignoring any NaN values
+#[inline]
 pub fn min_f64<I>(i: I) -> Option<f64>
 where
   I: Iterator<Item = f64>,
@@ -14,6 +15,7 @@ where
 
 /// Finds the minimum of an iterator of f64s using the given predicate, ignoring
 /// any NaN values
+#[inline]
 pub fn min_f64_by_key<I, F>(i: I, f: F) -> Option<f64>
 where
   I: Iterator<Item = f64>,

assignment-1b/writeup.md

@@ -3,36 +3,118 @@ geometry: margin=2cm
 output: pdf_document
 ---
 
+# Raytracer part B
+
 This project implements a raytracer with Blinn-Phong illumination implemented.
 The primary formula that is used by this implementation is:
 
-$$
+\begin{equation}
-I_{\lambda} = k_a O_{d\lambda} +
+I_{\lambda} =
-  \sum_{i=1}^{n_\textrm{lights}} \left(
+k_a O_{d\lambda} +
-    IL_{i\lambda} \left[
+\sum_{i=1}^{n_\textrm{lights}} \left(
-      k_d O_{d\lambda} \textrm{max} \{
+IL_{i\lambda} \left[
-        % 0, \overrightarrow{N} \middot \vec{L_i}
+k_d O_{d\lambda} \max ( 0, \vec{N} \cdot \vec{L_i} ) +
-      \}
+k_s O_{s\lambda} \max ( 0, \vec{N} \cdot \vec{H_i} )^n
-    \right]
+\right]
-  \right)
+\right)
-$$
+\end{equation}
+
+Where:
+
+- $I_{\lambda}$ is the final illumination of the pixel on an object
+- $k_a$ is the material's ambient reflectivity
+- $k_d$ is the material's diffuse reflectivity
+- $k_s$ is the material's specular reflectivity
+- $n_\textrm{lights}$ is the number of lights
+- $IL_{i\lambda}$ is the intensity of light $i$
+- $O_{d\lambda}$ is the object's diffuse color
+- $O_{s\lambda}$ is the object's specular color
+- $\vec{N}$ is the normal vector to the object's surface
+- $\vec{L_i}$ is the direction from the intersection point to the light $i$
+- $\vec{H_i}$ is halfway between the direction to the light $i$ and the
+  direction to the viewer
+- $n$ is the exponent for the specular component
 
 ## Varying $k_a$
 
-![Varying $k_a$](examples/ka-demo.png){width=240px}
+$k_a$ is the strength of ambient light. It's used as a coefficient for the
+object's diffuse color, which keeps a constant value independent of the
+positions of the object, light, and the viewer. In the image below, I varied
+$k_a$ between 0.2 and 1. Note how the overall color of the ball increases or
+decreases in brightness when all other factors remain constant.
+
+![Varying $k_a$](examples/ka-demo.png){width=360px}
+\ 
 
 ## Varying $k_d$
 
-![Varying $k_d$](examples/kd-demo.png){width=240px}
+TODO
+
+![Varying $k_d$](examples/kd-demo.png){width=360px}
+\ 
 
 ## Varying $k_s$
 
-![Varying $k_s$](examples/ks-demo.png){width=240px}
+TODO
+
+![Varying $k_s$](examples/ks-demo.png){width=360px}
+\ 
 
 ## Varying $n$
 
-![Varying $n$](examples/n-demo.png){width=240px}
+$n$ 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.
+
+![Varying $n$](examples/n-demo.png){width=360px}
+\ 
+
+## Multiple lights
+
+Multiple lights are handled by multiplying each light against an intensity
+level, and then added together. Unfortunately, this means that the intensity of
+each light can't be too bright. We rely on the image to not use lights that are
+too bright. Because this may result in color values above 1.0, the final value
+is clamped against 1.0. Below is an example of a scene with two lights; one to
+the left and one to the right:
+
+![Multiple lights](examples/multiple-lights-demo.png){width=360px}
+\ 
+
+## Shadows
+
+Shadows are implemented by pointing a second ray between the intersection point
+of the original view ray and each light. If the light has something obstructing
+it in the middle, the light's effect is not used.
+
+The soft shadow effect is realized by jittering rays across an area. In my
+implementation, a jitter radius of about 1.0 is used, and 75 rays are shot into
+uniformly sampled points within that radius. This also has the side effect that
+rays that are closer to the original ray are sampled more frequently. Each of
+these rays produces either 0 or 1 depending on if it was obstructed by the
+object. Taking the proportion of rays that hit as a coefficient for the shadow,
+we can get some soft shadow effects like this:
+
+![Soft shadows](examples/soft-shadow-demo.png){width=360px}
+\ 
+
+## Depth Cueing
+
+Depth cueing is when the objects further from the viewer have a lower opacity to
+"fade" into the background in some sense. A good example of this can be seen in
+the image below; note how the objects are less and less bright the further they
+are away from the eye.
+
+![Depth cueing](examples/depth-cueing-demo.png){width=360px}
+\ 
+
+## Shortcomings of the model
+
+The model cannot be used to represent TODO
 
 # Arbitrary Objects
 
-![Varying $n$](examples/objects.png){width=240px}
+![Objects in the scene](examples/objects.png){width=360px}
+\ 
+

participation/2023-02-15.md

@@ -0,0 +1,11 @@
+# Participation Question 1
+
+**What are the complications that you can imagine that results from including
+the points on the side of the triangle in the triangle or not?**
+
+_Hint: Two triangles that share a border may have problems._
+
+# Participation Question 2
+
+**When d11 \* d22 - d12 \* d12 = 0, the system will have no solution. When might
+this happen, and what does it mean?**