Question

好的，我是XNA编程中的菜鸟，对我来说很光鲜。我已经在微软网站上关注如何让第一人称相机旋转并在XNA中移动3D世界的教程。但是当我沿着它的Y轴旋转相机时，它不会移动它旋转/面对的方向，而是移动它就像它面向它最初面对的方向一样。

这是我的代码：

static Vector3 avatarPosition = new Vector3(0, 0, 0);
static Vector3 cameraPosition = avatarPosition;
Vector3 cameraReference = new Vector3(10, 0, 0);
// Create a vector pointing the direction the camera is facing.
Matrix world = Matrix.CreateWorld(new Vector3(0, -1, 0), Vector3.Forward, Vector3.Up);
Matrix rotationMatrix = Matrix.CreateRotationY(MathHelper.ToRadians(0));
int Rot = 0;
Vector3 worldVector = new Vector3(5,-2, 0);
Matrix view, proj;
Vector3 cameraLookat;
Update()
{
    world = Matrix.CreateWorld(worldVector, Vector3.Forward, Vector3.Up);
    if (IsKeyDown(Keys.W))
        avatarPosition += new Vector3(0.2f, 0f, 0);
    if (IsKeyDown(Keys.S))
        avatarPosition += new Vector3(-0.2f, 0f, 0);
    if (IsKeyDown(Keys.A))
        avatarPosition += new Vector3(0f, 0f, -0.2f);
    if (IsKeyDown(Keys.D))
        avatarPosition += new Vector3(0f, 0f, 0.2f);

    if (IsKeyDown(Keys.Left))
        Rot += 1;
    if (IsKeyDown(Keys.Right))
        Rot += -1;

    rotationMatrix = Matrix.CreateRotationY(MathHelper.ToRadians(Rot));
    // Create a vector pointing the direction the camera is facing.
    Vector3 transformedReference = Vector3.Transform(cameraReference, rotationMatrix);
    // Calculate the position the camera is looking at.
    cameraLookat = transformedReference + cameraPosition;
    // Set up the view matrix and projection matrix.
    view = Matrix.CreateLookAt(cameraPosition, cameraLookat, new Vector3(0.0f, 1.0f, 0.0f));

    proj = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45), graphics.GraphicsDevice.Viewport.AspectRatio,
                                          0.1f, 1000);
    cameraPosition = avatarPosition;
 }

有人可以告诉我为什么相机不会像旋转那样移动吗？或者有人可以给我一个该死的代码来制作一个？感谢。

Answer 1

我看到您遇到的问题来自代码的这个区域：

if (IsKeyDown(Keys.W))
    avatarPosition += new Vector3(0.2f, 0f, 0);
if (IsKeyDown(Keys.S))
    avatarPosition += new Vector3(-0.2f, 0f, 0);
if (IsKeyDown(Keys.A))
    avatarPosition += new Vector3(0f, 0f, -0.2f);
if (IsKeyDown(Keys.D))
    avatarPosition += new Vector3(0f, 0f, 0.2f);

不是直接沿x轴或z轴平移avatarPosition，而应该使用你指向的方向，它似乎是你的transformedReference变量。

例如，要向前移动相机的方向：

if (IsKeyDown(Keys.W))
    avatarPosition += transformedReference;

但是，由于transformedReference变量似乎已经规范化，因此它可能无法将化身移动到您希望的距离。在这种情况下，简单地将它乘以一些常量MOVEMENT_SPEED，如下所示：

if (IsKeyDown(Keys.W))
    avatarPosition += transformedReference * MOVEMENT_SPEED;

朝相机方向移动相机

1 个答案: