Browse Source

Starting working on area lights.

Godzil 4 years ago
parent
commit
c4b680789e

+ 23 - 0
source/include/light.h

@@ -14,9 +14,13 @@
 #include <renderstat.h>
 #include <stdio.h>
 
+class World;
+
 enum LightType
 {
     POINT_LIGHT = 0,
+    AREA_LIGHT,
+
 };
 
 class Light
@@ -26,15 +30,34 @@ public:
     Tuple position;
     LightType type;
 
+    /* For area light */
+    Tuple corner;
+    Tuple uVec;
+    Tuple vVec;
+    uint32_t samples;
+    uint32_t uSteps;
+    uint32_t vSteps;
+
 public:
     Light(LightType type = POINT_LIGHT, Tuple position=Point(0, 0, 0),
           Colour intensity=Colour(1, 1, 1)) : type(type), position(position), intensity(intensity)
           { stats.addLight(); };
+    Light(LightType type, Tuple corner, Tuple fullUVec, uint32_t uSteps, Tuple fullVVec, uint32_t vSteps,
+            Colour intensity, bool jitter = false): type(type), corner(corner), uVec(fullUVec / uSteps), uSteps(uSteps),
+            vVec(fullVVec / vSteps), vSteps(vSteps), intensity(intensity)
+    {
+        this->samples = this->vSteps * this->uSteps;
+        this->position = this->corner + ((fullUVec + fullVVec) / 2);
+        stats.addLight();
+    };
+    double intensityAt(World &w, Tuple point);
 
     bool operator==(const Light &b) const { return this->intensity == b.intensity &&
                                                    this->position == b.position &&
                                                    this->type == b.type; };
 
+    Tuple pointOnLight(uint32_t u, uint32_t v);
+
     void dumpMe(FILE *fp);
 };
 

+ 2 - 1
source/include/material.h

@@ -36,7 +36,8 @@ public:
     Material() : colour(Colour(1, 1, 1)), ambient(0.1), diffuse(0.9), specular(0.9), shininess(200),
            reflective(0.0), transparency(0.0), emissive(0), refractiveIndex(1.0), pattern(nullptr) {};
 
-    Colour lighting(Light light, Tuple point, Tuple eyeVector, Tuple normalVector, Shape *hitObject, bool inShadow = false);
+    Colour lighting(Light light, Tuple point, Tuple eyeVector, Tuple normalVector, Shape *hitObject,
+            double lightIntensity = 1.0);
 
     bool operator==(const Material &b) const { return double_equal(this->ambient,   b.ambient) &&
                                                       double_equal(this->diffuse,   b.diffuse) &&

+ 1 - 1
source/include/world.h

@@ -45,7 +45,7 @@ public:
 
     Tuple shadeHit(Computation comps, uint32_t depthCount = 4);
     Tuple colourAt(Ray r, uint32_t depthCount = 4);
-    bool isShadowed(Tuple point, uint32_t light = 0);
+    bool isShadowed(Tuple point, Tuple lightPosition);
 
     Colour reflectColour(Computation comps, uint32_t depthCount = 4);
     Colour refractedColour(Computation comps, uint32_t depthCount = 4);

+ 32 - 0
source/shapes/light.cpp

@@ -8,6 +8,7 @@
  */
 #include <stdio.h>
 #include <light.h>
+#include <world.h>
 
 void Light::dumpMe(FILE *fp)
 {
@@ -16,4 +17,35 @@ void Light::dumpMe(FILE *fp)
     fprintf(fp, "\"Position\": {\"x\": %f, \"y\": %f, \"z\":%f},\n",
             this->position.x, this->position.y, this->position.z);
     fprintf(fp, "\"Type\": \"PointLight\",\n");
+}
+
+double Light::intensityAt(World &w, Tuple point)
+{
+    switch(this->type)
+    {
+    case POINT_LIGHT:
+    default:
+        return (w.isShadowed(point, this->position))?0.0:1.0;
+
+    case AREA_LIGHT:
+        double total = 0.0;
+        uint32_t v, u;
+        for(v = 0; v < this->vSteps; v++)
+        {
+            for(u = 0; u < this->uSteps; u++)
+            {
+                if (!w.isShadowed(point, this->pointOnLight(u, v)))
+                {
+                    total = total + 1.0;
+                }
+            }
+        }
+        return total / this->samples;
+        break;
+    }
+}
+
+Tuple Light::pointOnLight(uint32_t u, uint32_t v)
+{
+    return this->corner + this->uVec * (u+0.5) + this->vVec * (v+0.5);
 }

+ 21 - 19
source/shapes/material.cpp

@@ -11,7 +11,8 @@
 #include <colour.h>
 #include <shape.h>
 
-Colour Material::lighting(Light light, Tuple point, Tuple eyeVector, Tuple normalVector, Shape *hitObject, bool inShadow)
+Colour Material::lighting(Light light, Tuple point, Tuple eyeVector, Tuple normalVector, Shape *hitObject,
+        double lightIntensity)
 {
     Colour pointColor = this->colour;
 
@@ -36,33 +37,34 @@ Colour Material::lighting(Light light, Tuple point, Tuple eyeVector, Tuple norma
 
     emissiveColour = pointColor * this->emissive;
 
-    if (!inShadow)
+    lightDotNormal = lightVector.dot(normalVector);
+
+    if (lightDotNormal < 0)
+    {
+        diffuseColour = Colour(0, 0, 0);
+        specularColour = Colour(0, 0, 0);
+    }
+    else
     {
-        lightDotNormal = lightVector.dot(normalVector);
+        diffuseColour = effectiveColour * this->diffuse * lightDotNormal;
+        reflectVector = -lightVector.reflect(normalVector);
+
+        reflectDotEye = reflectVector.dot(eyeVector);
 
-        if (lightDotNormal < 0)
+        if (reflectDotEye < 0)
         {
-            diffuseColour = Colour(0, 0, 0);
             specularColour = Colour(0, 0, 0);
         }
         else
         {
-            diffuseColour = effectiveColour * this->diffuse * lightDotNormal;
-            reflectVector = -lightVector.reflect(normalVector);
-
-            reflectDotEye = reflectVector.dot(eyeVector);
-
-            if (reflectDotEye < 0)
-            {
-                specularColour = Colour(0, 0, 0);
-            }
-            else
-            {
-                double factor = pow(reflectDotEye, this->shininess);
-                specularColour = light.intensity * this->specular * factor;
-            }
+            double factor = pow(reflectDotEye, this->shininess);
+            specularColour = light.intensity * this->specular * factor;
         }
     }
+
+    diffuseColour = diffuseColour * lightIntensity;
+    specularColour = specularColour * lightIntensity;
+
     finalColour = emissiveColour + ambientColour + diffuseColour + specularColour;
 
     return Colour(finalColour.x, finalColour.y, finalColour.z);

+ 4 - 4
source/world.cpp

@@ -102,10 +102,10 @@ Tuple World::shadeHit(Computation comps, uint32_t depthCount)
 
     for(lightIndex = 0; lightIndex < this->lightCount; lightIndex++)
     {
-        bool isThereAnObstacle = this->isShadowed(comps.overHitPoint, lightIndex);
+        double lightLevel = this->lightList[lightIndex]->intensityAt(*this, comps.overHitPoint);
 
         surface = surface + comps.material->lighting(*this->lightList[lightIndex], comps.overHitPoint, comps.eyeVector,
-                                                        comps.normalVector, comps.object, isThereAnObstacle);
+                                                        comps.normalVector, comps.object, lightLevel);
     }
     Tuple reflected = this->reflectColour(comps, depthCount);
     Tuple refracted = this->refractedColour(comps, depthCount);
@@ -137,9 +137,9 @@ Tuple World::colourAt(Ray r, uint32_t depthCount)
     }
 }
 
-bool World::isShadowed(Tuple point, uint32_t light)
+bool World::isShadowed(Tuple point, Tuple lightPosition)
 {
-    Tuple v = this->lightList[light]->position - point;
+    Tuple v = lightPosition - point;
     double distance = v.magnitude();
     Tuple direction = v.normalise();
 

+ 12 - 0
tests/CMakeLists.txt

@@ -90,6 +90,16 @@ target_include_directories(ch14_test PUBLIC ../source/include)
 target_sources(ch14_test PRIVATE ch14_test.cpp)
 target_link_libraries(ch14_test rayonnement)
 
+add_executable(arealight_test)
+target_include_directories(arealight_test PUBLIC ../source/include)
+target_sources(arealight_test PRIVATE arealight_test.cpp)
+target_link_libraries(arealight_test rayonnement)
+
+add_executable(triangle_rendertest)
+target_include_directories(triangle_rendertest PUBLIC ../source/include)
+target_sources(triangle_rendertest PRIVATE triangle_rendertest.cpp)
+target_link_libraries(triangle_rendertest rayonnement)
+
 add_executable(christmasball_render)
 target_include_directories(christmasball_render PUBLIC ../source/include)
 target_sources(christmasball_render PRIVATE christmasball_render.cpp)
@@ -107,7 +117,9 @@ add_test(NAME Chapter12_Test COMMAND $<TARGET_FILE:ch12_test>)
 add_test(NAME Chapter13_Test COMMAND $<TARGET_FILE:ch13_test>)
 add_test(NAME Chapter13_ConeBonus COMMAND $<TARGET_FILE:ch13_cone>)
 add_test(NAME Chapter14_Test COMMAND $<TARGET_FILE:ch14_test>)
+add_test(NAME AreaLight_Test COMMAND $<TARGET_FILE:arealight_test>)
 add_test(NAME Test_Rendering COMMAND $<TARGET_FILE:test_render>)
+add_test(NAME Triangle_RenderTest COMMAND $<TARGET_FILE:triangle_rendertest>)
 add_test(NAME ChristmasBall_Rendering COMMAND $<TARGET_FILE:christmasball_render>)
 add_test(NAME Hw3Render COMMAND $<TARGET_FILE:hw3render> ${CMAKE_CURRENT_SOURCE_DIR}/test.hw3scene)
 add_test(NAME Hw3RenderAllCmds COMMAND $<TARGET_FILE:hw3render> ${CMAKE_CURRENT_SOURCE_DIR}/test_keys.hw3scene)

+ 99 - 0
tests/arealight_test.cpp

@@ -0,0 +1,99 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Render test for reflection in chapter 13.
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <world.h>
+#include <light.h>
+#include <sphere.h>
+#include <plane.h>
+#include <cube.h>
+#include <cylinder.h>
+#include <material.h>
+#include <colour.h>
+#include <canvas.h>
+#include <camera.h>
+#include <group.h>
+#include <cone.h>
+
+#include <pattern.h>
+#include <strippattern.h>
+#include <gradientpattern.h>
+#include <checkerspattern.h>
+#include <ringpattern.h>
+
+#include <transformation.h>
+
+int main()
+{
+    World w = World();
+
+    /* Add lights */
+#if 0
+    Light light1 = Light(AREA_LIGHT, Point(-1, 2, 4),
+            Vector(2, 0, 0), 8,
+            Vector(0, 2, 0), 8,
+            //jitter,
+            Colour(1.5, 1.5, 1.5));
+#else
+    Light light1 = Light(POINT_LIGHT, Point(-1, 2, 4), Colour(1.5,1.5,1.5));
+#endif
+    w.addLight(&light1);
+
+
+    /* ----------------------------- */
+
+    /* Cube that pretend to be the light */
+    Cube c = Cube();
+    c.material.colour = Colour(1.5, 1.5, 1.5);
+    c.material.ambient = 1;
+    c.material.diffuse = 0;
+    c.material.specular = 0;
+    c.dropShadow = false;
+    c.setTransform(translation(0, 3, 4) * scaling(1, 1, 0.01));
+    w.addObject(&c);
+
+    Plane p = Plane();
+    p.material.colour = Colour(1, 1, 1);
+    p.material.ambient = 0.025;
+    p.material.diffuse = 0.67;
+    p.material.specular = 0;
+    w.addObject(&p);
+
+    Sphere s1 = Sphere();
+    s1.setTransform(translation(0.5, 0.5,0) * scaling(0.5, 0.5, 0.5));
+    s1.material.colour = Colour(1, 0, 0);
+    s1.material.ambient = 0.1;
+    s1.material.specular = 0;
+    s1.material.diffuse = 0.6;
+    s1.material.reflective = 0.3;
+    w.addObject(&s1);
+
+    Sphere s2 = Sphere();
+    s2.setTransform(translation(-0.25, 0.33,0) * scaling(0.33, 0.33, 0.33));
+    s2.material.colour = Colour(0.5, 0.5, 1);
+    s2.material.ambient = 0.1;
+    s2.material.specular = 0;
+    s2.material.diffuse = 0.6;
+    s2.material.reflective = 0.3;
+    w.addObject(&s2);
+
+    /* ----------------------------- */
+
+    /* Set the camera */
+    //Camera camera = Camera(400, 160, 0.7854);
+    Camera camera = Camera(800, 320, 0.7854);
+    camera.setTransform(viewTransform(Point(-3, 1, 2.5),
+                                      Point(0, 0.5, 0),
+                                      Vector(0, 1, 0)));
+
+    /* Now render it */
+    Canvas image = camera.render(w, 5);
+
+    image.SaveAsPNG("arealight_test.png");
+
+    return 0;
+}

+ 125 - 0
tests/light_test.cpp

@@ -11,6 +11,8 @@
 #include <colour.h>
 #include <tuple.h>
 #include <gtest/gtest.h>
+#include <world.h>
+#include <worldbuilder.h>
 
 TEST(LightTest, A_point_lighthas_a_position_and_intensity)
 {
@@ -21,4 +23,127 @@ TEST(LightTest, A_point_lighthas_a_position_and_intensity)
 
     ASSERT_EQ(light.position, position);
     ASSERT_EQ(light.intensity, intensity);
+}
+
+TEST(LightTest, Point_lights_evaluate_the_lights_intensity_at_a_given_point)
+{
+    World w = DefaultWorld();
+    Light *light = w.getLight(0);
+
+    Tuple testList[] = {
+            Point(0, 1.0001, 0),
+            Point(-1.0001, 0, 0),
+            Point(0, 0, -1.0001),
+            Point(0, 0, 1.0001),
+            Point(1.0001, 0, 0),
+            Point(0, -1.0001, 0),
+            Point(0, 0, 0),
+    };
+
+    double testResult[] = {
+            1.0,
+            1.0,
+            1.0,
+            0.0,
+            0.0,
+            0.0,
+            0.0,
+    };
+
+    int testCount = sizeof(testList)/sizeof((testList)[0]);
+    int i;
+
+    for(i = 0; i < testCount; i++)
+    {
+        ASSERT_TRUE(double_equal(light->intensityAt(w, testList[i]), testResult[i]));
+    }
+}
+
+TEST(LightTest, Creating_an_area_light)
+{
+    Tuple corner = Point(0, 0, 0);
+    Tuple v1 = Vector(2, 0, 0);
+    Tuple v2 = Vector(0, 0, 1);
+
+    Light light = Light(AREA_LIGHT, corner, v1, 4, v2, 2, Colour(1, 1, 1));
+
+    /* Position is used to store the corner in area lights */
+    ASSERT_EQ(light.corner, corner);
+    ASSERT_EQ(light.uVec, Vector(0.5, 0, 0));
+    ASSERT_EQ(light.uSteps, 4);
+    ASSERT_EQ(light.vVec, Vector(0, 0, 0.5));
+    ASSERT_EQ(light.vSteps, 2);
+    ASSERT_EQ(light.samples, 8);
+    ASSERT_EQ(light.position, Point(1, 0, 0.5));
+}
+
+TEST(LightTest, Finding_a_single_point_on_an_area_light)
+{
+    Tuple corner = Point(0, 0, 0);
+    Tuple v1 = Vector(2, 0, 0);
+    Tuple v2 = Vector(0, 0, 1);
+
+    Light light = Light(AREA_LIGHT, corner, v1, 4, v2, 2, Colour(1, 1, 1));
+
+    uint32_t testList[][2] = {
+            {0, 0},
+            {1, 0},
+            {0, 1},
+            {2, 0},
+            {3, 1},
+    };
+
+    Point testResults[] {
+        Point(0.25, 0, 0.25),
+        Point(0.75, 0, 0.25),
+        Point(0.25, 0, 0.75),
+        Point(1.25, 0, 0.25),
+        Point(1.75, 0, 0.75),
+    };
+
+    int testCount = sizeof(testList)/sizeof((testList)[0]);
+    int i;
+
+    for(i = 0; i < testCount; i++)
+    {
+        Tuple tp = light.pointOnLight(testList[i][0], testList[i][1]);
+        ASSERT_EQ(tp, testResults[i]);
+    }
+
+}
+
+TEST(LightTest, The_area_light_intensity_function)
+{
+    World w = DefaultWorld();
+    Tuple corner = Point(-0.5, -0.5, -5);
+    Tuple v1 = Vector(1, 0, 0);
+    Tuple v2 = Vector(0, 1, 0);
+
+    Light light = Light(AREA_LIGHT, corner, v1, 2, v2, 2, Colour(1, 1, 1));
+
+    Point testList[] = {
+            Point(0, 0, 2),
+            Point(1, -1, 2),
+            Point(1.5, 0, 2),
+            Point(1.25, 1.25, 3),
+            Point(0, 0, -2),
+    };
+
+    double testResults[] {
+        0.0,
+        0.25,
+        0.5,
+        0.75,
+        1,
+    };
+
+    int testCount = sizeof(testList)/sizeof((testList)[0]);
+    int i;
+
+    for(i = 0; i < testCount; i++)
+    {
+        double intensity = light.intensityAt(w, testList[i]);
+        ASSERT_TRUE(double_equal(intensity, testResults[i]));
+    }
+
 }

+ 43 - 2
tests/material_test.cpp

@@ -11,6 +11,8 @@
 #include <colour.h>
 #include <testshape.h>
 #include <gtest/gtest.h>
+#include <world.h>
+#include <worldbuilder.h>
 
 TEST(MaterialTest, The_default_material)
 {
@@ -101,9 +103,9 @@ TEST(MaterialTest, Lighting_with_the_surface_in_shadow)
     Vector eyev = Vector(0, 0, -1);
     Vector normalv = Vector(0, 0, -1);
     Light light = Light(POINT_LIGHT, Point(0, 0, -10), Colour(1, 1, 1));
-    bool inShadow = true;
+    double lightLevel = 0.0;
 
-    Colour result = m.lighting(light, position, eyev, normalv, &t, inShadow);
+    Colour result = m.lighting(light, position, eyev, normalv, &t, lightLevel);
 
     ASSERT_EQ(result, Colour(0.1, 0.1, 0.1));
 }
@@ -164,4 +166,43 @@ TEST(MaterialTest, Equality_tests)
 
     m.colour = Colour(32, 32, 32);
     ASSERT_NE(m, m2);
+}
+
+TEST(MaterialTest, lighting_uses_light_intensity_to_attenuate_colour)
+{
+    World w = DefaultWorld();
+    Light *light = w.getLight(0);
+    Shape *shape = w.getObject(0);
+
+    light->position = Point(0, 0, -10);
+    light->intensity = Colour(1, 1, 1);
+
+    shape->material.ambient = 0.1;
+    shape->material.diffuse = 0.9;
+    shape->material.specular = 0;
+    shape->material.colour = Colour(1, 1, 1);
+    Tuple pt = Point(0, 0, -1);
+    Tuple eyev = Vector(0, 0, -1);
+    Tuple normalv = Vector(0, 0, -1);
+
+    double testList[] = {
+            1.0,
+            0.5,
+            0.0,
+    };
+
+    Colour testResult[] = {
+            Colour(1, 1, 1),
+            Colour(0.55, 0.55, 0.55),
+            Colour(0.1, 0.1, 0.1),
+    };
+
+    int testCount = sizeof(testList)/sizeof((testList)[0]);
+    int i;
+
+    for(i = 0; i < testCount; i++)
+    {
+        ASSERT_EQ(shape->material.lighting(*light, pt, eyev, normalv, shape, testList[i]), testResult[i]);
+    }
+
 }

+ 116 - 0
tests/triangle_rendertest.cpp

@@ -0,0 +1,116 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Render test for reflection in chapter 13.
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <world.h>
+#include <light.h>
+#include <plane.h>
+#include <colour.h>
+#include <canvas.h>
+#include <camera.h>
+#include <triangle.h>
+#include <group.h>
+#include <time.h>
+
+#include <transformation.h>
+
+double frand(double max)
+{
+    return max * (rand() / ((double) RAND_MAX));
+}
+
+int main()
+{
+    World w = World();
+
+    /* Add lights */
+    Light light1 = Light(POINT_LIGHT, Point(10000, 10000, -10000), Colour(0.25, 0.25, 0.25));
+    w.addLight(&light1);
+    Light light2 = Light(POINT_LIGHT, Point(-10000, 10000, -10000), Colour(0.25, 0.25, 0.25));
+    w.addLight(&light2);
+    Light light3 = Light(POINT_LIGHT, Point(10000, -10000, -10000), Colour(0.25, 0.25, 0.25));
+    w.addLight(&light3);
+    Light light4 = Light(POINT_LIGHT, Point(-10000, -10000, -10000), Colour(0.25, 0.25, 0.25));
+    w.addLight(&light4);
+
+    /* ----------------------------- */
+
+    /* White background */
+    Plane p = Plane();
+    p.setTransform(translation(0, 0, 100) *  rotationX(1.5708));
+    p.material.colour = Colour(1, 1, 1);
+    p.material.ambient = 1;
+    p.material.diffuse = 0;
+    p.material.specular = 0;
+    w.addObject(&p);
+
+    /* ----------------------------- */
+
+    Group g = Group();
+
+    srand(10); /* Force the seed to a known value */
+
+    int i;
+    Point p1, p2, p3;
+    /* Let's add a bunche of "random" triangles */
+    for (i = 0; i < 10; i++)
+    {
+        p1.x = 7-frand(14);
+        p1.y = 7-frand(14);
+        p1.z = 7-frand(14);
+        p2.x = 7-frand(14);
+        p2.y = 7-frand(14);
+        p2.z = 7-frand(14);
+        p3.x = 7-frand(14);
+        p3.y = 7-frand(14);
+        p3.z = 7-frand(14);
+
+        Triangle *tri = new Triangle(p1, p2, p3);
+        tri->material.colour.x = frand(1); // red
+        tri->material.colour.y = frand(1); // green
+        tri->material.colour.z = frand(1); // blue
+
+        //tri->material.refractiveIndex = frand(2);
+        //tri->material.transparency = frand(1);
+        //tri->material.shininess = frand(300);
+        //tri->material.specular = frand(1);
+        //tri->material.ambient = frand(1);
+        tri->material.reflective = frand(1);
+        //tri->material.diffuse = frand(1);
+
+
+        g.addObject(tri);
+    }
+
+    g.setTransform(rotationX(3.14));
+
+    w.addObject(&g);
+
+    /* ----------------------------- */
+
+    FILE *fpOut = fopen("triangles_world.json", "wt");
+    if (fpOut)
+    {
+        w.dumpMe(fpOut);
+        fclose(fpOut);
+    }
+
+    /* ----------------------------- */
+
+    /* Set the camera */
+    Camera camera = Camera(500, 500, M_PI/1.5);
+    camera.setTransform(viewTransform(Point(0, 0, -9),
+                                      Point(0, 0, 0),
+                                      Vector(0, 1, 0)));
+
+    /* Now render it */
+    Canvas image = camera.render(w, 5);
+
+    image.SaveAsPNG("triangle_rendertest.png");
+
+    return 0;
+}

+ 30 - 4
tests/world_test.cpp

@@ -120,7 +120,7 @@ TEST(WorldTest, There_is_no_shadow_when_nothing_is_collinear_with_point_and_ligh
     World w = DefaultWorld();
     Tuple p = Point(0, 10, 0);
 
-    ASSERT_FALSE(w.isShadowed(p));
+    ASSERT_FALSE(w.isShadowed(p, w.getLight(0)->position));
 }
 
 TEST(WorldTest, The_shadow_when_an_object_is_between_the_point_and_the_light)
@@ -128,7 +128,7 @@ TEST(WorldTest, The_shadow_when_an_object_is_between_the_point_and_the_light)
     World w = DefaultWorld();
     Tuple p = Point(10, -10, 10);
 
-    ASSERT_TRUE(w.isShadowed(p));
+    ASSERT_TRUE(w.isShadowed(p, w.getLight(0)->position));
 }
 
 TEST(WorldTest, There_is_no_shadow_whne_an_object_is_behing_the_light)
@@ -136,7 +136,7 @@ TEST(WorldTest, There_is_no_shadow_whne_an_object_is_behing_the_light)
     World w = DefaultWorld();
     Tuple p = Point(-20, 20, -20);
 
-    ASSERT_FALSE(w.isShadowed(p));
+    ASSERT_FALSE(w.isShadowed(p, w.getLight(0)->position));
 }
 
 TEST(WorldTest, There_is_no_shadow_when_an_object_is_behing_the_point)
@@ -144,7 +144,7 @@ TEST(WorldTest, There_is_no_shadow_when_an_object_is_behing_the_point)
     World w = DefaultWorld();
     Tuple p = Point(-2, 2, -2);
 
-    ASSERT_FALSE(w.isShadowed(p));
+    ASSERT_FALSE(w.isShadowed(p, w.getLight(0)->position));
 }
 
 TEST(WorldTest, Shade_hit_is_given_an_intersection_in_shadow)
@@ -426,4 +426,30 @@ TEST(WorldTest, Shade_hit_with_a_reflective_transparent_material)
     ASSERT_EQ(c, Colour(0.93391, 0.69643, 0.69243));
 
     set_equal_precision(FLT_EPSILON);
+}
+
+TEST(WorldTest, Is_shadow_test_for_occlusion_between_two_points)
+{
+    World w = DefaultWorld();
+    Tuple lightPosition = Point(-10, -10, -10);
+
+    Point testList[]  = {
+            Point(-10, -10, 10),
+            Point(10, 10, 10),
+            Point(-20, -20, 20),
+            Point(-5, -5, 5),
+    };
+    bool testResult[] = {
+            false,
+            true,
+            false,
+            false,
+    };
+    int testCount = sizeof(testList)/sizeof((testList)[0]);
+    int i;
+
+    for(i = 0; i < testCount; i++)
+    {
+        ASSERT_EQ(w.isShadowed(lightPosition, testList[i]), testResult[i]);
+    }
 }