基本上我想要做的是使用一个非常基本的光线投射系统对 2D 高度图进行着色，该系统基本上只是检查光线是否在应该对其进行着色之前被拦截。但是它不能正常工作，我已经为此苦苦挣扎了几个小时，所以我认为把它交给你们不会有什么坏处，因为我认为这可能是非常明显的事情，我不会看到它或如此复杂，我永远不会绕着它走。
我有一张这样的地图：
光线投射给了我这个（请记住，它只是调试颜色；红色是光线拦截，但在预期位置（如此阴影）之前，蓝色将是正确位置的光线拦截（如此突出或原样），并且黄色表示该点在 while 循环切断之前根本没有光线相互作用）。
结果应该是背面的斜坡和大山后面的区域（阴影）为红色，面向太阳的斜坡（高光）为蓝色。不应该有任何黄色。所以这张图片表明要么所有的光线都击中了错误的位置，要么光线在到达目标之前总是在其他地方相交，这是不可能的。
在这一点上，我高度怀疑问题出在我的三角上。
这是 Ray 类：
class Ray
{
public Vector2 Position;
public Vector2 Direction; // Think in XZ coordinates for these (they are on a perpendicular plane to the heightmap)
// Angle is angle from horizon (I think), and height is height above zero (arbitrary)
public float Angle, Height;
private TerrainUnit[,] Terrainmap;
private float U, V;
public Ray(ref TerrainUnit[,] Terrainmap, float height, float angle)
{
this.Terrainmap = Terrainmap;
this.Angle = angle;
this.Height = this.V = height;
// Create new straight vector
this.Direction = new Vector2(0, 1);
// Rotate it to the values determined by the angle
this.Direction = Vector2.Transform(Direction, Matrix.CreateRotationX(Angle));
//this.Direction = new Vector2((float)Math.Sin(angle), -(float)Math.Cos(angle));
// Find the horizontal distance of the origin-destination triangle
this.U = V / (float)Math.Tan(Angle);
// Bleh just initialize the vector to something
this.Position = new Vector2(U, V);
}
public void CastTo(int x, int y)
{
// Get the height of the target terrain unit
float H = (float)Terrainmap[x, y].Height;
// Find where the ray would have to be to intersect that terrain unit based on its angle and height
Position = new Vector2(x - U, H + V);
float Z = 1000 * (float)Terrainmap[0, y].Height;
// As long as the ray is not below the terrain and not past the destination point
while (Position.Y > Z && Position.X <= x)
{
// If the ray has passed into terrain bounds update Z every step
if (Position.X > 0) Z = 1000 * (float)Terrainmap[(int)Position.X, y].Height;
Position.X += Direction.X;
Position.Y += Direction.Y;
}
Terrainmap[x, y].TypeColor = Color.Yellow;
if ((int)Position.X == x) Terrainmap[x, y].TypeColor = Color.Blue;
else Terrainmap[x, y].TypeColor = Color.Red;
}
}
同样作为一种形式，投射每条光线的函数以及我如何称呼它：
if (lighting) CastSunRays(1f, MathHelper.PiOver4);
private void CastSunRays(float height, float angle)
{
Ray ray = new Ray(ref Terrainmap, height, angle);
for (int x = 0; x < Width; x++)
for (int y = 0; y < Height; y++)
ray.CastTo(x, y);
}
