public static Matrix44f CreateYBillboardMatrix(Matrix44f matrix)
{
double theta = -Math.Atan2(matrix.V2.X, matrix.V2.Z);
float ct = (float)Math.Cos(theta);
float st = (float)Math.Sin(theta);
float x = 0;
float y = 1;
float z = 0;
Matrix44f ret = new Matrix44f();
ret.V0 = new Vector4f(1, 0, 0, 0);
ret.V1 = new Vector4f(0, 1, 0, 0);
ret.V2 = new Vector4f(0, 0, 1, 0);
ret.V3 = new Vector4f(0, 0, 0, 1);
ret.V0.X = x * x + ct * (1 - x * x) + st * 0;
ret.V1.X = x * y + ct * (0 - x * y) + st * -z;
ret.V2.X = x * z + ct * (0 - x * z) + st * y;
ret.V0.Y = y * x + ct * (0 - y * x) + st * z;
ret.V1.Y = y * y + ct * (1 - y * y) + st * 0;
ret.V2.Y = y * z + ct * (0 - y * z) + st * -x;
ret.V0.Z = z * x + ct * (0 - z * x) + st * -y;
ret.V1.Z = z * y + ct * (0 - z * y) + st * x;
ret.V2.Z = z * z + ct * (1 - z * z) + st * 0;
return ret;
}
public static Matrix44f CreateYBillboardMatrix(Matrix44f matrix)
{
double theta = -Math.Atan2(matrix.V2.X, matrix.V2.Z);
float ct = (float)Math.Cos(theta);
float st = (float)Math.Sin(theta);
float x = 0;
float y = 1;
float z = 0;
Matrix44f ret = new Matrix44f();
ret.V0 = new Vector4f(1, 0, 0, 0);
ret.V1 = new Vector4f(0, 1, 0, 0);
ret.V2 = new Vector4f(0, 0, 1, 0);
ret.V3 = new Vector4f(0, 0, 0, 1);
ret.V0.X = x * x + ct * (1 - x * x) + st * 0;
ret.V1.X = x * y + ct * (0 - x * y) + st * -z;
ret.V2.X = x * z + ct * (0 - x * z) + st * y;
ret.V0.Y = y * x + ct * (0 - y * x) + st * z;
ret.V1.Y = y * y + ct * (1 - y * y) + st * 0;
ret.V2.Y = y * z + ct * (0 - y * z) + st * -x;
ret.V0.Z = z * x + ct * (0 - z * x) + st * -y;
ret.V1.Z = z * y + ct * (0 - z * y) + st * x;
ret.V2.Z = z * z + ct * (1 - z * z) + st * 0;
return(ret);
}
public Matrix44f Transpose()
{
Matrix44f ret = new Matrix44f();
ret.V0 = new Vector4f(V0.X, V1.X, V2.X, V3.X);
ret.V1 = new Vector4f(V0.Y, V1.Y, V2.Y, V3.Y);
ret.V2 = new Vector4f(V0.Z, V1.Z, V2.Z, V3.Z);
ret.V3 = new Vector4f(V0.W, V1.W, V2.W, V3.W);
return ret;
}
public Matrix44f Transpose()
{
Matrix44f ret = new Matrix44f();
ret.V0 = new Vector4f(V0.X, V1.X, V2.X, V3.X);
ret.V1 = new Vector4f(V0.Y, V1.Y, V2.Y, V3.Y);
ret.V2 = new Vector4f(V0.Z, V1.Z, V2.Z, V3.Z);
ret.V3 = new Vector4f(V0.W, V1.W, V2.W, V3.W);
return(ret);
}
public static Matrix44f CreateBillboardMatrix(Vector3f pos, Vector3f camPos, Vector3f camUp)
{
Vector3f look = camPos - pos;
look = look.Normalize();
Vector3f right = camUp.CrossProduct(look);
Vector3f up = look.CrossProduct(right);
Matrix44f ret = new Matrix44f();
ret.V0 = right;
ret.V1 = up;
ret.V2 = look;
ret.V3 = new Vector4f(pos, 1);
return ret;
}
public static Matrix44f CreateBillboardMatrix(Vector3f pos, Vector3f camPos, Vector3f camUp)
{
Vector3f look = camPos - pos;
look = look.Normalize();
Vector3f right = camUp.CrossProduct(look);
Vector3f up = look.CrossProduct(right);
Matrix44f ret = new Matrix44f();
ret.V0 = right;
ret.V1 = up;
ret.V2 = look;
ret.V3 = new Vector4f(pos, 1);
return(ret);
}