public void A_ray_misses_a_CSG_object()
{
var csg = new CsgShape(CsgOperation.Union, new Sphere(), new Cube());
var ray = new Ray(new Point(0, 2, -5), new Vector(0, 0, 1));
var intersections = csg.LocalIntersect(ray);
intersections.Should().BeEmpty();
}
public void A_ray_hits_a_CSG_object()
{
var left = new Sphere();
var right = new Sphere(transform: Matrix4x4.CreateTranslation(0, 0, 0.5));
var csg = new CsgShape(CsgOperation.Union, left, right);
var ray = new Ray(new Point(0, 0, -5), new Vector(0, 0, 1));
var intersections = csg.LocalIntersect(ray);
intersections.Should().HaveCount(2);
intersections.Ts.Should().ContainInOrder(4, 6.5);
intersections.Shapes.Should().ContainInOrder(left, right);
}
public void A_CSG_shape_is_composed_of_an_operation_and_two_operand_shapes()
{
var sphere = new Sphere();
var cube = new Cube();
var csg = new CsgShape(CsgOperation.Union, sphere, cube);
csg.Operation.Should().Be(CsgOperation.Union);
csg.Left.Should().Be(sphere);
csg.Right.Should().Be(cube);
sphere.Parent.Should().Be(csg);
cube.Parent.Should().Be(csg);
}
public void A_CSG_difference_preserves_all_intersections_not_exclusively_inside_the_object_on_the_right(
bool isLeftHit,
bool isWithinLeft,
bool isWithinRight,
bool expectedResult)
{
CsgShape.IsIntersectionAllowed(
CsgOperation.Difference,
isLeftHit,
isWithinLeft,
isWithinRight)
.Should()
.Be(expectedResult);
}
public void A_CSG_intersect_preserves_all_intersections_where_both_shapes_overlap(
bool isLeftHit,
bool isWithinLeft,
bool isWithinRight,
bool expectedResult)
{
CsgShape.IsIntersectionAllowed(
CsgOperation.Intersection,
isLeftHit,
isWithinLeft,
isWithinRight)
.Should()
.Be(expectedResult);
}
public void A_CSG_union_preserves_all_intersections_on_the_exterior_of_both_shapes(
bool isLeftHit,
bool isWithinLeft,
bool isWithinRight,
bool expectedResult)
{
CsgShape.IsIntersectionAllowed(
CsgOperation.Union,
isLeftHit,
isWithinLeft,
isWithinRight)
.Should()
.Be(expectedResult);
}
Given_a_set_of_intersections_produce_a_subset_of_only_those_intersections_that_conform_to_the_operation_of_the_current_CSG_object(
CsgOperation operation,
int intersectionIndex1,
int intersectionIndex2)
{
var left = new Sphere();
var right = new Cube();
var csg = new CsgShape(operation, left, right);
var intersections = new IntersectionList((1, left), (2, right), (3, left), (4, right));
var filtered = csg.FilterIntersections(intersections);
filtered.Should()
.HaveCount(2)
.And.ContainInOrder(intersections[intersectionIndex1], intersections[intersectionIndex2]);
}
protected override Canvas Render(CameraRenderOptions options)
{
// Shapes
var floorCeiling = new Cube(
"FloorCeiling",
Matrix4x4.CreateTranslation(0, 1, 0).Scale(20, 7, 20),
new Material(
pattern: new CheckerPattern(
Colors.Black,
Colors.DarkGray,
Matrix4x4.CreateScaling(0.07, 0.07, 0.07)),
ambient: 0.25,
diffuse: 0.7,
specular: 0.9,
shininess: 300,
reflective: 0.1));
var walls = new Cube(
"Walls",
Matrix4x4.CreateScaling(10, 10, 10),
new Material(
pattern: new CheckerPattern(
new Color(0.4863, 0.3765, 0.2941),
new Color(0.3725, 0.2902, 0.2275),
Matrix4x4.CreateScaling(0.05, 20, 0.05)),
ambient: 0.1,
diffuse: 0.7,
specular: 0.9,
shininess: 300,
reflective: 0.1));
var csgUnion = new CsgShape(
"Union",
CsgOperation.Union,
new Cube(
"YellowCube",
Matrix4x4.CreateTranslation(0, 1.5, 0),
new Material(Colors.Yellow, diffuse: 0.7, specular: 0.3)),
new Sphere(
"RedSphere",
Matrix4x4.CreateTranslation(0.6, 2, -0.6),
new Material(Colors.Red, diffuse: 0.7, specular: 0.9)),
transform: Matrix4x4.CreateRotationY(-Math.PI / 3).Translate(-4, 0, -2));
var csgIntersection = new CsgShape(
"Intersection",
CsgOperation.Intersection,
new Cube(
"YellowCube",
Matrix4x4.CreateTranslation(0, 1.5, 0),
new Material(Colors.Yellow, diffuse: 0.7, specular: 0.3)),
new Sphere(
"RedSphere",
Matrix4x4.CreateTranslation(0.6, 2, -0.6),
new Material(Colors.Red, diffuse: 0.7, specular: 0.9)),
transform: Matrix4x4.CreateRotationY(-Math.PI / 2).Translate(0, 0, -2));
var csgDifference = new CsgShape(
"Difference",
CsgOperation.Difference,
new Cube(
"YellowCube",
Matrix4x4.CreateTranslation(0, 1.5, 0),
new Material(Colors.Yellow, diffuse: 0.7, specular: 0.3)),
new Sphere(
"RedSphere",
Matrix4x4.CreateTranslation(0.6, 2, -0.6),
new Material(Colors.Red, diffuse: 0.7, specular: 0)),
transform: Matrix4x4.CreateRotationY(-Math.PI / 6).Translate(3, 0, 2));
// Lights, camera, action.
var light = new PointLight(new Point(8, 8, -5), Colors.White);
var world = new World(light, floorCeiling, walls, csgUnion, csgIntersection, csgDifference);
var cameraTransform = Matrix4x4.CreateLookAt(new Point(8, 6, -8), new Point(0, 3, 0), Vector.UnitY);
var camera = new Camera(CanvasWidth, CanvasHeight, fieldOfView: 0.785, cameraTransform);
Canvas canvas = camera.Render(world, options);
return(canvas);
}
