自己根据C++ D3D的源码改写一个相机类(第一人称)。

1 using System;  2 using System.Collections.Generic;  3 using System.Linq;  4 using System.Text;  5 using Microsoft.DirectX;  6 using Microsoft.DirectX.PrivateImplementationDetails;  7 using Microsoft.DirectX.Direct3D;  8   9 namespace AppScene 10 { 11     public enum CameraType { LANDOBJECT, AIRCRAFT }; 12     public class Camera 13     { 14         CameraType mCameraType; 15         Vector3 mPosition; //相机位置 16         Vector3 mLook;//LookVector   17         Vector3 mUp;// UpVector   18         Vector3 mRight;// RightVector   19         Vector3 ViewFrustum;// 平面截投体   20  21         protected Viewport mViewPort;//视口大小 22         protected Matrix m_ProjectionMatrix; //上一次渲染采用的投影变换矩阵 Projection matrix used in last render. 23         protected Matrix m_ViewMatrix; //上一次渲染采用的观察矩阵 View matrix used in last render. 24         protected Matrix m_WorldMatrix = Matrix.Identity;//世界变换矩阵 25         public Camera() 26         { 27             mCameraType = CameraType.AIRCRAFT; 28             mPosition = new Vector3(0.0f, 0.0f, -50.0f);//注意默认位置，现在对了。 29             mRight = new Vector3(0.0f, 1.0f, 0.0f); 30             mUp = new Vector3(0.0f, 1.0f, 0.0f); 31             mLook = new Vector3(0.0f, 0.0f, 10.0f); 32         } 33         public Camera(Vector3 cameraPosition, Vector3 cameraTarget, Vector3 upVector) 34         { 35             mCameraType = CameraType.AIRCRAFT; 36             mPosition = new Vector3(0.0f, 0.0f, -100.0f); 37             mRight = new Vector3(1.0f, 0.0f, 0.0f); 38             mUp = new Vector3(0.0f, 1.0f, 0.0f); 39             mLook = new Vector3(0.0f, 0.0f, 0.0f); 40         } 41         public void setCameraType(CameraType cameraType) 42         { 43             mCameraType = cameraType; 44         } 45         //前后移动 46         public void walk(float units) 47         { 48             // move only on xz plane for land object 49             if (mCameraType == CameraType.LANDOBJECT) 50                 mPosition += new Vector3(mLook.X, 0.0f, mLook.Z) * units; 51  52             if (mCameraType == CameraType.AIRCRAFT) 53                 mPosition += mLook * units; 54         } 55         //左右移动，扫射 56         public void strafe(float units) 57         { 58             // move only on xz plane for land object 59             if (mCameraType == CameraType.LANDOBJECT) 60                 mPosition += new Vector3(mRight.X, 0.0f, mRight.Z) * units; 61  62             if (mCameraType == CameraType.AIRCRAFT) 63                 mPosition += mRight * units; 64         } 65         //上下移动 66         public void fly(float units) 67         { 68             // move only on y-axis for land object 69             if (mCameraType == CameraType.LANDOBJECT) 70                 mPosition.Y += units; 71  72             if (mCameraType == CameraType.AIRCRAFT) 73                 mPosition += mUp * units; 74         } 75  76         // 倾斜角  77         public void Pitch(float angle) 78         { 79             Matrix T = Matrix.Identity; 80             //D3DXMatrixRotationAxis(&T, &_right, angle); 81             T.RotateAxis(mRight, angle); 82             // rotate _up and _look around _right vector 83             mUp.TransformCoordinate(T); 84             mLook.TransformCoordinate(T); 85             //D3DXVec3TransformCoord(&_up, &_up, &T); 86             //D3DXVec3TransformCoord(&_look, &_look, &T); 87         } 88         //俯仰角 89         public void Roll(float angle) 90         { 91             // only roll for aircraft type 92             if (mCameraType == CameraType.AIRCRAFT) 93             { 94                 Matrix T = Matrix.Identity; 95                 T.RotateAxis(mLook, angle); 96  97                 // rotate _up and _right around _look vector 98                 mRight.TransformCoordinate(T); 99                 mUp.TransformCoordinate(T);100             }101         }102         // 航偏角103         public void Yaw(float angle)104         {105             Matrix T = Matrix.Identity;106 107             // rotate around world y (0, 1, 0) always for land object108             if (mCameraType == CameraType.LANDOBJECT)109                 T.RotateY(angle);110             // rotate around own up vector for aircraft111             if (mCameraType == CameraType.AIRCRAFT)112                 T.RotateAxis(mUp, angle);113 114             // rotate _right and _look around _up or y-axis115             mRight.TransformCoordinate(T);116             mLook.TransformCoordinate(T);117         }118         public void SetPosition(Vector3 position)// 设置相机世界坐标  119         {120             mPosition = position;121         }122         //更新相机状态123         public Matrix UpdateCamera()124         {125             Matrix mViewMatrix = Matrix.Identity;126             // Keep camera's axes orthogonal to eachother127             //D3DXVec3Normalize(&_look, &_look);128             mLook.Normalize();129             //D3DXVec3Cross(&, &_look, &_right);130             // _up = Vector3.Cross(_look, _right);131             //D3DXVec3Normalize(&_up, &_up);132             mUp.Normalize();133             //D3DXVec3Cross(&_right, &_up, &_look);134             mRight = Vector3.Cross(mUp, mLook);135             //D3DXVec3Normalize(&_right, &_right);136             mRight.Normalize();137             // Build the view matrix:138             //float x = -D3DXVec3Dot(&_right, &_pos);139             //float y = -D3DXVec3Dot(&_up, &_pos);140             //float z = -D3DXVec3Dot(&_look, &_pos);141             float x = -Vector3.Dot(mRight, mPosition);142             float y = -Vector3.Dot(mUp, mPosition);143             float z = -Vector3.Dot(mLook, mPosition);144 145             mViewMatrix.M11 = mRight.X; mViewMatrix.M12 = mUp.X; mViewMatrix.M13 = mLook.X; mViewMatrix.M14 = 0.0f;146             mViewMatrix.M21 = mRight.Y; mViewMatrix.M22 = mUp.Y; mViewMatrix.M23 = mLook.Y; mViewMatrix.M24 = 0.0f;147             mViewMatrix.M31 = mRight.Z; mViewMatrix.M32 = mUp.Z; mViewMatrix.M33 = mLook.Z; mViewMatrix.M34 = 0.0f;148             mViewMatrix.M41 = x; mViewMatrix.M42 = y; mViewMatrix.M43 = z; mViewMatrix.M44 = 1.0f;149             return mViewMatrix;150         }151 152         public void Update(Microsoft.DirectX.Direct3D.Device m_Device3d)153         {154             Matrix V = UpdateCamera();155             m_Device3d.SetTransform(TransformType.View, V);156         }157         //视口大小158         public Viewport Viewport159         {160             get161             {162                 return mViewPort;163             }164         }165         //观察变换矩阵166         public Matrix ViewMatrix167         {168             get169             {170                 return m_ViewMatrix;171             }172         }173         //投影变换矩阵174         public Matrix ProjectionMatrix175         {176             get177             {178                 return m_ProjectionMatrix;179             }180         }181         //世界变换矩阵182         public Matrix WorldMatrix183         {184             get185             {186                 return m_WorldMatrix;187             }188         }189         /// 
190         /// UnProject和Project之前需要调用该方法191         /// 
192         /// 193         public void ComputeMatrix(Device m_Device3d)194         {195             m_WorldMatrix = m_Device3d.GetTransform(TransformType.World);196             m_ProjectionMatrix = m_Device3d.GetTransform(TransformType.Projection);197             m_ViewMatrix = m_Device3d.GetTransform(TransformType.View);198             mViewPort = m_Device3d.Viewport;199         }200         /// 
201         /// Projects a point from world to screen coordinates.202         /// 计算指定世界坐标的屏幕坐标203         /// 
204         /// Point in world space205         /// 
      
       Point in screen space
      206         public Vector3 Project(Vector3 point)207         {208             point.Project(mViewPort, m_ProjectionMatrix, m_ViewMatrix, m_WorldMatrix);209             return point;210         }211 212         internal Vector3 UnProject(Vector3 v1)213         {214             v1.Unproject(mViewPort, m_ProjectionMatrix, m_ViewMatrix, m_WorldMatrix);215             return v1;216         }217     }218 }

增加一个围绕某条射线旋转的方法：

1  // 2         public void RotateRay(float angle, Vector3 vOrigin, Vector3 vAxis) 3         { 4             // 计算新的焦点 5             Vector3 vView = mLook - vOrigin; 6             Matrix temp = Matrix.RotationAxis(vAxis, angle); 7             vView.TransformCoordinate(temp); 8             //vView.RotateAxis(angle, vAxis); 9             mLook = vOrigin + vView;10 11             // 计算新的视点12             vView = mPosition - vOrigin;13            // Matrix temp2 = Matrix.RotationAxis(vAxis, angle);14             vView.TransformCoordinate(temp);15             //vView.RotateAxis(angle, vAxis);16             mPosition = vOrigin + vView;17 18             mUp.TransformCoordinate(temp);19           //  m_strafe.RotateAxis(angle, vAxis);20         }