ポリゴン上に点が含まれるかを判定

detectPointIsEnclosedByPolygon.cs

/// <summary>
/// ポリゴン上に点が含まれるかを判定
/// </summary>
bool detectPointIsEnclosedByPolygon (Vector3 p, Vector3 v0, Vector3 v1, Vector3 v2) {
	Vector3 n = Vector3.Normalize (Vector3.Cross (v1 - v0, v2 - v1));

	Vector3 n0 = Vector3.Normalize (Vector3.Cross (v1 - v0, p - v1));
	Vector3 n1 = Vector3.Normalize (Vector3.Cross (v2 - v1, p - v2));
	Vector3 n2 = Vector3.Normalize (Vector3.Cross (v0 - v2, p - v0));

	if ((1.0f - Vector3.Dot (n, n0)) > 0.001f) return false;
	if ((1.0f - Vector3.Dot (n, n1)) > 0.001f) return false;
	if ((1.0f - Vector3.Dot (n, n2)) > 0.001f) return false;

	return true;
}