public void CanFailToIntersectWhenRayParallelToPlane()
{
// Arrange
var plane = new Plane() { Point = new Vector(0, 0, 0), Norm = new Vector(0, 1, 0) };
var ray = new Ray() { Start = new Vector(0, 1, 0), Direction = new Vector(1, 0, 0) };
// Act
var isect = plane.Intersect(ray);
// Assert
Assert.IsNull(isect);
}
public void CanFailToInsersectWithRayFacingAwayFromSphere()
{
// Arrange
var sphere = new Sphere() { Center = new Vector(0, 0, 0), Radius = 1 };
var ray = new Ray() { Start = new Vector(0, 0, -2), Direction = new Vector(0, 0, -1) };
// Act
var isect = sphere.Intersect(ray);
// Assert
Assert.IsNull(isect);
}
public void CanFailToInsersectParallelLine()
{
// Arrange
var line = new Line() { Point = new Vector(0, 1, 0), Direction = new Vector(1, 0, 0) };
var ray = new Ray() { Start = new Vector(0, 0, 0), Direction = new Vector(1, 0, 0) };
// Act
var isect = line.Intersect(ray);
// Assert
Assert.IsNull(isect);
}
public void CanInsersectPlane()
{
// Arrange
var plane = new Plane() { Point = new Vector(0, 0, 0), Norm = new Vector(0, 1, 0) };
var ray = new Ray() { Start = new Vector(0, 1, 0), Direction = new Vector(0, -1, 0) };
// Act
var isect = plane.Intersect(ray);
// Assert
Assert.NotNull(isect);
Assert.AreEqual(1, isect.Distance);
Assert.AreEqual(plane, isect.Element);
}
public void CanIntersectEdgeOfSphere()
{
// Arrange
var sphere = new Sphere() { Center = new Vector(0, 0, 0), Radius = 1 };
var ray = new Ray() { Start = new Vector(1, 0, -2), Direction = new Vector(0, 0, 1) };
// Act
var isect = sphere.Intersect(ray);
// Assert
Assert.NotNull(isect);
Assert.AreEqual(2, isect.Distance);
Assert.AreEqual(sphere, isect.Element);
}
public void CanInsersectLine()
{
// Arrange
var line = new Line() { Point = new Vector(0, 1, 0), Direction = new Vector(1, 0, 0) };
var ray = new Ray() { Start = new Vector(0, 0, 0), Direction = new Vector(1, 1, 0) };
// Act
var isect = line.Intersect(ray);
// Assert
Assert.NotNull(isect);
Assert.AreEqual(Math.Sqrt(2), isect.Distance);
Assert.AreEqual(line, isect.Element);
}
/// <summary>
/// Trace a ray through the scene
/// </summary>
/// <param name="ray">The ray to test</param>
/// <param name="scene">The scene description</param>
/// <param name="depth">The current depth of recursion</param>
/// <returns>The color of the pixel</returns>
private Color TraceRay(Ray ray, Scene scene, int depth)
{
var intersection = scene.ClosestIntersection(ray);
if (intersection == null)
{
return Color.Background;
}
return this.Shade(intersection, scene, depth);
}
public void CanInsersectPolygon_Square_NearTopRight()
{
// Arrange
var points = new List<Vector>() { new Vector(0, 0, 0), new Vector(1, 0, 0), new Vector(1, 1, 0), new Vector(0, 1, 0) };
var poly = new Polygon(points, new Vector(0, 0, 1));
var ray = new Ray() { Start = new Vector(0.9, 0.9, 0.5), Direction = new Vector(0, 0, -1) };
// Act
var isect = poly.Intersect(ray);
// Assert
Assert.NotNull(isect);
Assert.AreEqual(0.5, isect.Distance);
Assert.AreEqual(poly, isect.Element);
}
public void CanFindPointOfIntersection()
{
// Arrange
var points = new List<Vector>() { new Vector(0, 0, 0), new Vector(1, 0, 0), new Vector(1, 1, 0), new Vector(0, 1, 0) };
var poly = new Polygon(points, new Vector(0, 0, 1));
var ray = new Ray() { Start = new Vector(0.5, 0.5, 0.5), Direction = new Vector(0, 0, -1) };
// Act
var isect = poly.GetPointOfIntersectionWithPlane(ray);
// Assert
Assert.NotNull(isect);
Assert.AreEqual(0.5, isect.X);
Assert.AreEqual(0.5, isect.Y);
}
public void CanFailToIntersectPlaneWithParallelRay()
{
// Arrange
var points = new List<Vector>() { new Vector(0, 0, 0), new Vector(1, 0, 0), new Vector(1, 1, 0), new Vector(0, 1, 0) };
var poly = new Polygon(points, new Vector(0, 0, 1));
var ray = new Ray() { Start = new Vector(1, 0, 0.5), Direction = new Vector(1, 0, 0) };
// Act
var isect = poly.GetPointOfIntersectionWithPlane(ray);
// Assert
Assert.IsNull(isect);
}
public void CanFailToInsersectTheBackFaceOfAPolygon()
{
// Arrange
var points = new List<Vector>() { new Vector(0, 0, 0), new Vector(1, 0, 0), new Vector(1, 1, 0), new Vector(0, 1, 0) };
var poly = new Polygon(points, new Vector(0, 0, 1));
var ray = new Ray() { Start = new Vector(0.5, 0.5, -0.5), Direction = new Vector(0, 0, 1) };
// Act
var isect = poly.Intersect(ray);
// Assert
Assert.IsNull(isect);
}
public void CanFailToInsersectPolygon_Square_NegativeMiss()
{
// Arrange
var points = new List<Vector>() { new Vector(0, 0, 0), new Vector(1, 0, 0), new Vector(1, 1, 0), new Vector(0, 1, 0) };
var poly = new Polygon(points, new Vector(0, 0, 1));
var ray = new Ray() { Start = new Vector(-0.5, 0.5, 0.5), Direction = new Vector(0, 0, -1) };
// Act
var isect = poly.Intersect(ray);
// Assert
Assert.IsNull(isect);
}