public void RayMissesP2P3Edge()
{
var p1 = pt.Point(0, 1, 0);
var p2 = pt.Point(-1, 0, 0);
var p3 = pt.Point(1, 0, 0);
var t = new shape.Triangle(p1, p2, p3);
var r = new Ray(pt.Point(0, -1, -2), pt.Vector(0, 0, 1));
var xs = t.Intersect(r);
Assert.Empty(xs);
}
public void IntersectingRayParallelToTriangle()
{
var p1 = pt.Point(0, 1, 0);
var p2 = pt.Point(-1, 0, 0);
var p3 = pt.Point(1, 0, 0);
var t = new shape.Triangle(p1, p2, p3);
var r = new Ray(pt.Point(0, -1, -2), pt.Vector(0, 1, 0));
var xs = t.Intersect(r);
Assert.Empty(xs);
}
public void IntersectionCanEncapsulateUV()
{
var p1 = pt.Point(0, 1, 0);
var p2 = pt.Point(-1, 0, 0);
var p3 = pt.Point(1, 0, 0);
var s = new shape.Triangle(p1, p2, p3);
var i = Intersection.WithUV(3.5, s, 0.2, 0.4);
Assert.Equal(0.2, i.U);
Assert.Equal(0.4, i.V);
}
public void RayStrikesTriangle()
{
var p1 = pt.Point(0, 1, 0);
var p2 = pt.Point(-1, 0, 0);
var p3 = pt.Point(1, 0, 0);
var t = new shape.Triangle(p1, p2, p3);
var r = new Ray(pt.Point(0, 0.5, -2), pt.Vector(0, 0, 1));
var xs = t.Intersect(r);
Assert.Single(xs);
Assert.Equal(2, xs[0].T);
}
public void FindingNormalOnTriangle()
{
var p1 = pt.Point(0, 1, 0);
var p2 = pt.Point(-1, 0, 0);
var p3 = pt.Point(1, 0, 0);
var t = new shape.Triangle(p1, p2, p3);
var n1 = t.TestNormalLocal(pt.Point(0, 0.5, 0));
var n2 = t.TestNormalLocal(pt.Point(-0.5, 0.75, 0));
var n3 = t.TestNormalLocal(pt.Point(0.5, 0.25, 0));
Assert.Equal(n1, t.Normal);
Assert.Equal(n2, t.Normal);
Assert.Equal(n3, t.Normal);
}
public void ConstructionTriangle()
{
var p1 = pt.Point(0, 1, 0);
var p2 = pt.Point(-1, 0, 0);
var p3 = pt.Point(1, 0, 0);
var t = new shape.Triangle(p1, p2, p3);
Assert.Equal(p1, t.P1);
Assert.Equal(p2, t.P2);
Assert.Equal(p3, t.P3);
Assert.Equal(pt.Vector(-1, -1, 0), t.Edge1);
Assert.Equal(pt.Vector(1, -1, 0), t.Edge2);
Assert.Equal(pt.Vector(0, 0, -1), t.Normal);
}