RTv1 - Let there be light

Ray tracer in C

🚀 Clone and Run

cd ~/Desktop; gcl https://github.com/gouiferda/RTv1.git; cd RTv1; make run;

📝 To do

• Minilibx functions

• expose properly (mlx_expose_hook)

• Functions and structures

  • vector
  • ray
  • figure (sphere,plane,cylinder,cone)
  • camera
  • light

• Mapping the coords system (0,0,0) to screen (0,0)

• ambiant light / intersection with ray

  • sphere
  • plane
  • cylinder
  • cone

• diffusion: lambert diffuse model

• specular: blinn specular model

• Shadows

• Moving and rotating the objects

• Moving and rotating the camera

• Norm & Handle errors and leaks and messages

• Multi lights (spots)

• Reflection

• Extra Bonuses: Antialiasing, External files for scene description, Reflection, Transparency, Shadow according to transparency...

• Research/learn about: ray tracing and vectors in maths

• Do a test and understand: plane line intersection

• cylinder/line intersection

• cone/line intersection

• Antialiasing

• create YML maps parser (Read External files for scene description)

🗺 Key definitions

• Ambiant: Color alone of the object
• Diffuse: controls roghness/dullness of object
• Specular: controls shinningness (noticable in : metal , marbles)
• Specular + Diffuse: How surface responds to light
• Indirect illumination: Light bounding off of other objects in the scene (Reflected rays)
• Shading model: diffuse + specular reflection

Lambert: (Diffuse)

To caluclate the color we need:

1. surface normal (intersection point - center of sphere) normalized
2. direction to the light (light pos - intersection point) normalized
3. do a dot product
4. refelective color of the sphere

each rgb has from 0 to 1 color = (l.n) x light.intensity x color of figure rgb color = (L.N) x M diff x color of figure rgb L: Ray towards light direction N: normal at hit pos, M diffuse: material's diffuse coeficcient // how much the figure is absorbing light / 1 max 0 min C object: color of object Dot product should not be negative

Blinn-Phong shading model: (Specular shading)

Phong_term = (V.R)^k

V- Ray towards viewer R- Light ray reflexted direction k - Material's specular coefficient (shininess) (L: intersection to light, N normal, R referse of L : reflection, V intersection to viewer ray to point) Dot product should not be negative

Half way vector:

H = L + V H = norm (H)

Blinn term = (H.R)^k

Material:

• Color:base color
• Ambient: what color it reflects in ambient light
• Diffuse: what color it reflect in diffuse light
• Specular: what is the color of its specular hihglight

🔗 Helpful links

Ray tracing explained

• Easy explaination
• Khan academy course: Basics and the Mathematics of rendering
• Udacity course: Interactive 3D Graphics
• Ray tracing 1
• A Ray Tracer - Part 1
• A Ray Tracer - Part 2

Ray/Line intersection with figures/objects

• Intersection of a Line and a sphere
• Intersection of a Line and a Plane 1
• Intersection of a Line and a Plane 2
• Intersection of a Line and a Plane 3

Shading / Diffuse mat shading

• Ray Tracing: shading
• Building a Ray Tracer in Python