Question

我正在尝试编码两个合适的键来以适当的速度更新船舶旅行的前/后方向位置，我想出的是：在Cmodel：

//Update method
        public void Update(Vector3 position, Vector3 orientation)  
        {

            //TO DO - Create an updated version of this.local matrix


            this.local *= Matrix.CreateFromYawPitchRoll(orientation.Y, orientation.X, orientation.Z);

            this.local *= Matrix.CreateTranslation(position.X, position.Y, position.Z);
        }

比在Game1：

 protected override void Update(GameTime gameTime)
    {
        // Allows the game to exit
        if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
            this.Exit();

        // TODO: Add your update logic here
        //Update the camera
        camera.Update();

       KeyboardState keyState = Keyboard.GetState();

        // The time since Update was called last.
        float elapsed = (float)gameTime.ElapsedGameTime.TotalSeconds;

        float RotationAngle = 0;
        RotationAngle += elapsed;
        float circle = MathHelper.Pi * 2;
        RotationAngle = RotationAngle % circle;

        Vector3 orientation = new Vector3(0, 0, 0);
        Vector3 position = new Vector3(0, 0, 0);


        if (keyState.IsKeyDown(Keys.W))
            orientation.X = RotationAngle;

        if (keyState.IsKeyDown(Keys.S))
            orientation.X = -RotationAngle;

        if (keyState.IsKeyDown(Keys.A))
            orientation.Y = RotationAngle;

        if (keyState.IsKeyDown(Keys.D))
            orientation.Y = -RotationAngle;

        if (keyState.IsKeyDown(Keys.Z))
            orientation.Z = RotationAngle;

        if (keyState.IsKeyDown(Keys.X))
            orientation.Z = -RotationAngle;


        //TO DO - Code two suitable keys to update position in the forward/backward direction of Ship travel at a suitable velocity


        if (keyState.IsKeyDown(Keys.F))
            position.Z = 1f;
        if (keyState.IsKeyDown(Keys.B))
            position.Z = 1f;


        //Update the first model i.e. the Ship
        scene[0].Update(position, orientation);

        base.Update(gameTime);
    }

事情就是当我向左或向右旋转船头时，这些按钮仍然像背部一样工作，朝向我（相机）。 Iadd让它向后移动并向船的“鼻子”方向前进，船的方向？

ANSWER !!!! 我必须做的就是让它与不同的矩阵相乘：旋转首先比翻译和结束本地！谢谢大家的答案。这真是坐在我头上的大时间！

this.local = Matrix.CreateFromYawPitchRoll(orientation.Y, orientation.X, orientation.Z) * Matrix.CreateTranslation(position.X, position.Y, position.Z) * this.local;

Answer 1

记住你在学校的数学课！你的“船”在某一点，你有速度/距离和角度你想要移动它。这里有一些pseude代码可以提供帮助：

float a = math.rad(angle);
float newX = currentX + math.sin(a) * distanceToMove;
float newZ = currentZ - math.cos(a) * distanceToMove;

这是一个基本的矢量计算，我现在对轴不确定，但如果你用X，Y和Z修补一下，你应该搞清楚！对不起，如果上面的公式是错误的，那是很久以前因为我实际上做了这样的数学;）

Answer 2

我可能不对，因为我在AS3中做过这个。

当你旋转船时，你需要重新计算它的运动。

为了简化，如果只有X和Y，那么按键会移动10个单位（无论你的单位是多少（例如像素））。将船舶旋转到某个角度时，需要重新计算其在X和Y轴上的移动。

他的移动功能如下：

Ship.X += Math.Cos(currentAngle) * Ship.DefaultMoveUnits;
Ship.Y += Math.Sin(currentAngle) * Ship.DefaultMoveUnits;

XYZ的原则相同。

Answer 3

为了向前移动，您需要获得船的方向。这不是问题，因为您已经在代码中设置了方向：Matrix.CreateFromYawPitchRoll(orientation.Y, orientation.X, orientation.Z);
使用此RotationMatrix，您可以提取船首指向的方向所需的值：

//this method uses 'orientation' as the current orientation of the ship
public Vector3 GetForward()
{
    Matrix rotation = Matrix.CreateFromYawPitchRoll(orientation.Y, orientation.X, orientation.Z);
    //i don't know the matrix structure of XNA, but it should be possible
    //to access each field seperately
    //M13 is here: row 1, column 3
    //M23 is here: row 2, column 3 and so on
    return new Vector3(rotation.M13, rotation.M23, rotation.M33);
}

//now that you got the appropriate vector
//you just can move into the direction of this vector like
Vector3 position = new Vector3(0, 0, 0);
if(keyState.IsKeyDown(Keys.F))
{
    position += ship.GetForward();
}

position *= elapsed;

//update the position of the ship here

您可以使用相同的方法获取向右和向上的向量，只需使用旋转矩阵的其他列：

public Vector3 GetRight()
{
    Matrix rotation = Matrix.CreateFromYawPitchRoll(orientation.Y, orientation.X, orientation.Z);
    return new Vector3(rotation.M11, rotation.M21, rotation.M31);
}

public Vector3 GetUp()
{
    Matrix rotation = Matrix.CreateFromYawPitchRoll(orientation.Y, orientation.X, orientation.Z);
    return new Vector3(rotation.M12, rotation.M22, rotation.M32);
}

您可以通过否定相应的向量来获取所有其他方向（向后，向左，向下）。因此，为了获得向后的方向，请使用-GetForward()。

Answer 4

为了使其成功，我所要做的就是改变矩阵乘法：

this.local = Matrix.CreateFromYawPitchRoll（orientation.Y，orientation.X，orientation.Z）* Matrix.CreateTranslation（position.X，position.Y，position.Z）* this.local;

在C＃中向船舶的方向前后移动船舶

4 个答案: