Add refraction

.gitignore

@@ -1,5 +1,6 @@
 .idea
 .pyc
+.vscode
 __pycache__/
 *.egg-info/
 .installed.cfg

main.py

@@ -0,0 +1,37 @@
+from pyrt.geometry.sphere import Sphere
+from typing import List
+from pyrt.math import *
+from pyrt.light import *
+from pyrt.geometry import Triangle, Vertex, Sphere
+from pyrt.material import PhongMaterial
+from pyrt.camera import PerspectiveCamera
+from pyrt.renderer import SimpleRT 
+from pyrt.scene import Scene
+
+floormaterial = PhongMaterial(color=Vec3(0.5,0.5,0.5))
+sphere0material = PhongMaterial(color=Vec3(1.,0.,0.), transparency=0.5)
+sphere1material = PhongMaterial(color=Vec3(0.,0.,1.), transparency=0.7)
+
+camera = PerspectiveCamera(640, 480, 45)
+camera.setView(Vec3(0.,-10.,10.), Vec3(0.,0.,0.), Vec3(0.,0.,1.))
+
+scene = Scene()
+scene.add(Triangle(Vertex(position=(0, 0, 0)),
+                   Vertex(position=(0, 5, 0)),
+                   Vertex(position=(1, 5, 0)), material=PhongMaterial()))
+scene.setCamera(camera)
+scene.addLight(PointLight(Vec3(0,0,15)))
+
+# Add "floor"
+A = Vertex(position=(-5.0, -5.0, 0.0))
+B = Vertex(position=( 5.0, -5.0, 0.0))
+C = Vertex(position=( 5.0,  5.0, 0.0))
+D = Vertex(position=(-5.0,  5.0, 0.0))
+scene.add(Triangle(A,B,C, material=floormaterial))
+
+# Add spheres
+scene.add(Sphere(center=Vec3(2,-3.5,1.75), radius=1, material=sphere0material))
+scene.add(Sphere(center=Vec3(2,-1.5,1.75), radius=1, material=sphere1material))
+
+imgdata = SimpleRT(shadow=True, iterations=3).render(scene)
+imgdata.save('a.png')

pyrt/material/material.py

@@ -13,7 +13,7 @@ class Material(object):
 
     """Base Material Class"""
 
-    def __init__(self, color: Vec3 = Vec3(0.,0.,0.), shininess: float = 0.0, reflectivity: float = 0.5, refraction: float = 1.0):
+    def __init__(self, color: Vec3 = Vec3(0.,0.,0.), shininess: float = 0.0, reflectivity: float = 0.5, refraction: float = 1.0, transparency = 0.0):
         self.color = color
         self.shininess = shininess
         self.reflectivity = reflectivity
@@ -28,6 +28,7 @@ def __init__(self, color: Vec3 = Vec3(0.,0.,0.), shininess: float = 0.0, reflect
         Also check the "refract3" function in math/vecops.py
         """
         self.refraction = refraction
+        self.transparency = transparency
 
     @abstractmethod
     def shade(self, camera: Camera, ray: Ray, hitrecord: HitRecord,  lights: list) -> Vec3:

pyrt/material/phongmaterial.py

@@ -12,8 +12,8 @@ class PhongMaterial(Material):
 
     """Base Material Class"""
 
-    def __init__(self, color: Vec3 = Vec3(1.,1.,1.), shininess: float = 10.0, reflectivity: float = 0.0, refraction: float = 1.0):
-        Material.__init__(self, color, shininess, reflectivity, refraction)
+    def __init__(self, color: Vec3 = Vec3(1.,1.,1.), shininess: float = 10.0, reflectivity: float = 0.0, refraction: float = 1.0, transparency = 0.0):
+        Material.__init__(self, color, shininess, reflectivity, refraction, transparency)
 
     def shade(self, camera: Camera, ray: Ray, hitrecord: HitRecord,  lights: list) -> Vec3:
         """

pyrt/renderer/simplert.py

@@ -85,6 +85,22 @@ def _reflect(self, r: int, g: int, b: int, scene: Scene, ray: Ray, hitrecord: Hi
             return rnew, gnew, bnew, reflect_ray, reflect_hitrecord
         else:
             return r,g,b,None,None
+
+    def _refract(self, r: int, g: int, b: int, scene: Scene, ray: Ray, hitrecord: HitRecord, eta: float) -> tuple:
+        refract_ray = Ray(hitrecord.point, refract3(hitrecord.normal_g, ray.direction, hitrecord.material.refraction))
+        refract_hitrecord = HitRecord()
+
+        hit, rnew, gnew, bnew = self._shade(scene, refract_ray, refract_hitrecord)
+
+        if hit:
+            ref1 = hitrecord.material.transparency
+            ref2 = 1.-ref1
+            rnew = int ( ref1 * rnew + ref2 * r)
+            gnew = int ( ref1 * gnew + ref2 * g)
+            bnew = int ( ref1 * bnew + ref2 * b)
+            return rnew, gnew, bnew, refract_ray, refract_hitrecord
+        else:
+            return r,g,b,None,None
 
     def render(self, scene: Scene) -> RGBImage:
         if not scene.camera:
@@ -119,6 +135,15 @@ def render(self, scene: Scene) -> RGBImage:
                         self.num_secondary_rays += 1
                         if refray is None:
                             break
+
+                if hit and hitrecord.material.transparency != 0.0:
+                    refhit = hitrecord.copy()
+                    refray = ray.copy()
+                    for i in range(self.iterations - 1):
+                        r, g, b, refray, refhit = self._refract(r,g,b, scene, refray, refhit, 1)
+                        self.num_secondary_rays += 1
+                        if refray is None:
+                            break
 
                 image.drawPixelFast8(x, y, r, g, b)