vtk 自定义交互之 通过鼠标控制camera同时使用键盘控制actor
vtk 自定义交互之 通过鼠标控制camera同时使用键盘精确定量控制actor
场景需求：
vtk中可以使用 vtkInteractorStyleTrackballActor 交互器类来通过鼠标对单个actor的position进行调整，可以用于图像配准微调。另外，使用 vtkInteractorStyleTrackballCamera 类来通过鼠标对相机进行操作，调整观察整个vtk空间的角度。结合两者，可以实现调整观察角度和调整actor来进行某些操作，如动画，微调等。 但两者均通过鼠标来操作，不能同时操作。
虽然可以通过回调函数切换交互器来进行操作，但频繁操作不具有可行性，并且鼠标拖拽不能精确量化控制。
本文实现通过键盘控制actor，同时 通过鼠标控制相机，实现类似于fps游戏的效果。
说明
特点：精确量化控制，同时操作相机和actor
注意事项：
-
键盘交互时会拾取焦点，确保焦点在想要移动的actor上。
-
当actor的pickable状态设置为false时，可屏蔽本操作。
-
如发现本代码有bug，烦请指出以改正。
实现效果
默认通过键盘 “w” “a” “s” “d” “e” “f” 控制actor旋转， 按 左ctrl 键在旋转和平移间切换，然后 “w” “a” “s” “d” “e” “f” 控制actor的平移。
展示见如下视频：
vtk类似fps游戏控制相机和actor演示
代码
本代码基于vtk8.2测试通过,
#include 为导入vtk静态库的代码, 可通过别的方式加载。
ppzInteractorStyleTrackballActor.h
//ppzInteractorStyleTrackballActor.h
#ifndef PPZ_INTERACTORSTYLETRACKBALLACTOR_H
#define PPZ_INTERACTORSTYLETRACKBALLACTOR_H
#include ppzInteractorStyleTrackballActor.cpp
//ppzInteractorStyleTrackballActor.cpp
#include "ppzInteractorStyleTrackballActor.h"
#include "vtkCamera.h"
#include "vtkCellPicker.h"
#include "vtkCallbackCommand.h"
#include "vtkMath.h"
#include "vtkMatrix4x4.h"
#include "vtkObjectFactory.h"
#include "vtkProp3D.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkRenderer.h"
#include "vtkTransform.h"
vtkStandardNewMacro(InteractorStyleTrackballActor);
//----------------------------------------------------------------------------
InteractorStyleTrackballActor::InteractorStyleTrackballActor()
: m_isDoTranslation(false)
{
this->MotionFactor = 10.0;
this->InteractionProp = nullptr;
this->InteractionPicker = vtkCellPicker::New();
this->InteractionPicker->SetTolerance(0.001);
}
//----------------------------------------------------------------------------
InteractorStyleTrackballActor::~InteractorStyleTrackballActor()
{
this->InteractionPicker->Delete();
}
void InteractorStyleTrackballActor::Rotate(const double x, const double y,const double z)
{
if (this->CurrentRenderer == nullptr || this->InteractionProp == nullptr)
{
return;
}
vtkRenderWindowInteractor* rwi = this->Interactor;
vtkCamera* cam = this->CurrentRenderer->GetActiveCamera();
// First get the origin of the assembly
double* obj_center = this->InteractionProp->GetCenter();
// GetLength gets the length of the diagonal of the bounding box
double boundRadius = this->InteractionProp->GetLength() * 0.5;
// Get the view up and view right vectors
double view_up[3], view_look[3], view_right[3];
cam->OrthogonalizeViewUp();
cam->ComputeViewPlaneNormal();
cam->GetViewUp(view_up);
vtkMath::Normalize(view_up);
cam->GetViewPlaneNormal(view_look);
vtkMath::Cross(view_up, view_look, view_right);
vtkMath::Normalize(view_right);
// Get the furtherest point from object position+origin
double outsidept[3];
outsidept[0] = obj_center[0] + view_right[0] * boundRadius;
outsidept[1] = obj_center[1] + view_right[1] * boundRadius;
outsidept[2] = obj_center[2] + view_right[2] * boundRadius;
// Convert them to display coord
double disp_obj_center[3];
this->ComputeWorldToDisplay(obj_center[0], obj_center[1], obj_center[2],
disp_obj_center);
this->ComputeWorldToDisplay(outsidept[0], outsidept[1], outsidept[2],
outsidept);
double radius = sqrt(vtkMath::Distance2BetweenPoints(disp_obj_center,
outsidept));
double nxf = (rwi->GetEventPosition()[0] - disp_obj_center[0]) / radius;
double nyf = (rwi->GetEventPosition()[1] - disp_obj_center[1]) / radius;
double oxf = (rwi->GetLastEventPosition()[0] - disp_obj_center[0]) / radius;
double oyf = (rwi->GetLastEventPosition()[1] - disp_obj_center[1]) / radius;
/* if (((nxf * nxf + nyf * nyf) <= 1.0) &&
((oxf * oxf + oyf * oyf) <= 1.0))*/
{
double scale[3];
scale[0] = scale[1] = scale[2] = 1.0;
double** rotate = new double* [3];
rotate[0] = new double[4];
rotate[1] = new double[4];
rotate[2] = new double[4];
rotate[0][0] = x;
rotate[0][1] = view_up[0];
rotate[0][2] = view_up[1];
rotate[0][3] = view_up[2];
rotate[1][0] = y;
rotate[1][1] = view_right[0];
rotate[1][2] = view_right[1];
rotate[1][3] = view_right[2];
rotate[2][0] = z;
rotate[2][1] = view_look[0];
rotate[2][2] = view_look[1];
rotate[2][3] = view_look[2];
this->Prop3DTransform(this->InteractionProp,
obj_center,
3,
rotate,
scale);
delete[] rotate[0];
delete[] rotate[1];
delete[] rotate[2];
delete[] rotate;
if (this->AutoAdjustCameraClippingRange)
{
this->CurrentRenderer->ResetCameraClippingRange();
}
rwi->Render();
}
}
void InteractorStyleTrackballActor::Pan(const double x, const double y, const double z)
{
if (this->CurrentRenderer == nullptr || this->InteractionProp == nullptr)
{
return;
}
vtkRenderWindowInteractor* rwi = this->Interactor;
// Use initial center as the origin from which to pan
double* obj_center = this->InteractionProp->GetCenter();
double disp_obj_center[3], new_pick_point[4];
double old_pick_point[4], motion_vector[3];
this->ComputeWorldToDisplay(obj_center[0], obj_center[1], obj_center[2],
disp_obj_center);
this->ComputeDisplayToWorld(
disp_obj_center[0]+x,
disp_obj_center[1]+y,
disp_obj_center[2]+z,
new_pick_point);
this->ComputeDisplayToWorld(
disp_obj_center[0],
disp_obj_center[1],
disp_obj_center[2],
old_pick_point);
//转为屏幕display物理坐标系的平移
motion_vector[0] = new_pick_point[0] - old_pick_point[0];
motion_vector[1] = new_pick_point[1] - old_pick_point[1];
motion_vector[2] = new_pick_point[2] - old_pick_point[2];
if (this->InteractionProp->GetUserMatrix() != nullptr)
{
vtkTransform* t = vtkTransform::New();
t->PostMultiply();
t->SetMatrix(this->InteractionProp->GetUserMatrix());
t->Translate(motion_vector[0], motion_vector[1], motion_vector[2]);
this->InteractionProp->GetUserMatrix()->DeepCopy(t->GetMatrix());
t->Delete();
}
else
{
this->InteractionProp->AddPosition(motion_vector[0],
motion_vector[1],
motion_vector[2]);
}
if (this->AutoAdjustCameraClippingRange)
{
this->CurrentRenderer->ResetCameraClippingRange();
}
rwi->Render();
}
void InteractorStyleTrackballActor::OnChar()
{
if (m_isDoTranslation)//平移
{
switch (this->Interactor->GetKeyCode())
{
case 'w'://上
Pan(0, 1, 0);
break;
case 'a'://左
Pan(-1, 0, 0);
break;
case 's'://下
Pan(0, -1, 0);
break;
case 'd'://右
Pan(1, 0, 0);
break;
case 'q'://前
Pan(0, 0, 0.01);
break;
case 'e'://后
Pan(0, 0, -0.01);
break;
}
}
else//旋转
{
switch (this->Interactor->GetKeyCode())
{
case 'w'://上
Rotate(0, -3, 0);
break;
case 'a'://左
Rotate(-3, 0, 0);
break;
case 's'://下
Rotate(0, 3, 0);
break;
case 'd'://右
Rotate(3, 0, 0);
break;
case 'q'://前
Rotate(0, 0, 3);
break;
case 'e'://后
Rotate(0, 0, -3);
break;
}
}
}
void InteractorStyleTrackballActor::OnKeyPress()
{
auto keyChar = this->Interactor->GetKeySym();
const char* Control_L = "Control_L";
auto isEqual = strcmp(keyChar, Control_L);
if (isEqual == 0)
{
m_isDoTranslation = !m_isDoTranslation;
if (m_isDoTranslation)
{
std::cout << "translation" << std::endl;
}
else
{
std::cout << "rotation" << std::endl;
}
}
}
//----------------------------------------------------------------------------
void InteractorStyleTrackballActor::PrintSelf(ostream& os, vtkIndent indent)
{
this->Superclass::PrintSelf(os, indent);
}
void InteractorStyleTrackballActor::OnLeftButtonDown()
{
int x = this->Interactor->GetEventPosition()[0];
int y = this->Interactor->GetEventPosition()[1];
this->FindPokedRenderer(x, y);
this->FindPickedActor(x, y);
vtkInteractorStyleTrackballCamera::OnLeftButtonDown();
}
//----------------------------------------------------------------------------
void InteractorStyleTrackballActor::FindPickedActor(int x, int y)
{
this->InteractionPicker->Pick(x, y, 0.0, this->CurrentRenderer);
vtkProp* prop = this->InteractionPicker->GetViewProp();
if (prop != nullptr)
{
this->InteractionProp = vtkProp3D::SafeDownCast(prop);
}
else
{
this->InteractionProp = nullptr;
}
}
//----------------------------------------------------------------------------
void InteractorStyleTrackballActor::Prop3DTransform(vtkProp3D* prop3D,
double* boxCenter,
int numRotation,
double** rotate,
double* scale)
{
vtkMatrix4x4* oldMatrix = vtkMatrix4x4::New();
prop3D->GetMatrix(oldMatrix);
double orig[3];
prop3D->GetOrigin(orig);
vtkTransform* newTransform = vtkTransform::New();
newTransform->PostMultiply();
if (prop3D->GetUserMatrix() != nullptr)
{
newTransform->SetMatrix(prop3D->GetUserMatrix());
}
else
{
newTransform->SetMatrix(oldMatrix);
}
newTransform->Translate(-(boxCenter[0]), -(boxCenter[1]), -(boxCenter[2]));
for (int i = 0; i < numRotation; i++)
{
newTransform->RotateWXYZ(rotate[i][0], rotate[i][1],
rotate[i][2], rotate[i][3]);
}
if ((scale[0] * scale[1] * scale[2]) != 0.0)
{
newTransform->Scale(scale[0], scale[1], scale[2]);
}
newTransform->Translate(boxCenter[0], boxCenter[1], boxCenter[2]);
// now try to get the composite of translate, rotate, and scale
newTransform->Translate(-(orig[0]), -(orig[1]), -(orig[2]));
newTransform->PreMultiply();
newTransform->Translate(orig[0], orig[1], orig[2]);
if (prop3D->GetUserMatrix() != nullptr)
{
newTransform->GetMatrix(prop3D->GetUserMatrix());
}
else
{
prop3D->SetPosition(newTransform->GetPosition());
prop3D->SetScale(newTransform->GetScale());
prop3D->SetOrientation(newTransform->GetOrientation());
}
oldMatrix->Delete();
newTransform->Delete();
}
测试代码
testQuantitativeMovement.cpp
//testQuantitativeMovement.cpp
#include