vtkPropPicker pickup function

Pick up an object, the object picked up where the actor is, so if you want a different object is picked up separately, an object will create an actor.

Sample Code Function

1 to pick up an object, to retain the original property, this object is picked disposed red

Pick-up the next object, the object is picked up reinstate a color original, performs step 1 for the pickup object

Code

#include "vtkAutoInit.h"
VTK_MODULE_INIT(vtkRenderingOpenGL2);
VTK_MODULE_INIT(vtkInteractionStyle);

#include <vtkSmartPointer.h>
#include <vtkMath.h>
#include <vtkActor.h>
#include <vtkProperty.h>
#include <vtkSphereSource.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkObjectFactory.h>
#include <vtkSphereSource.h>
#include <vtkPolyDataMapper.h>
#include <vtkPropPicker.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

// Handle mouse events
// 拾取每次拾取到的是一个actor
class PropPickerInteractorStyle : public vtkInteractorStyleTrackballCamera
{
public:
	static PropPickerInteractorStyle* New();
	vtkTypeMacro(PropPickerInteractorStyle, vtkInteractorStyleTrackballCamera);
	// 构造函数初始化
	PropPickerInteractorStyle()
	{
		LastPickedActor = NULL;
		LastPickedProperty = vtkProperty::New();
	}
	virtual ~PropPickerInteractorStyle()
	{
		LastPickedProperty->Delete();
	}
	// 鼠标按下的时候拾取
	virtual void OnLeftButtonDown()
	{
		// 获取鼠标按下的平面坐标
		int* clickPos = this->GetInteractor()->GetEventPosition();

		// Pick from this location.
		vtkSmartPointer<vtkPropPicker>  picker = vtkSmartPointer<vtkPropPicker>::New();
		picker->Pick(clickPos[0], clickPos[1], 0, this->GetDefaultRenderer());

		double* pos = picker->GetPickPosition();
		// If we picked something before, reset its property
		if (this->LastPickedActor)
		{
			this->LastPickedActor->GetProperty()->DeepCopy(this->LastPickedProperty);// 获取上次的属性
		}
		this->LastPickedActor = picker->GetActor(); // 拾取到的新actor
		if (this->LastPickedActor)
		{
			// Save the property of the picked actor so that we can restore it next time
			this->LastPickedProperty->DeepCopy(this->LastPickedActor->GetProperty());// 记住这次拾取对象的属性，存到成员变量中
			// Highlight the picked actor by changing its properties
			this->LastPickedActor->GetProperty()->SetColor(1.0, 0.0, 0.0); // 拾取到的对象，设置成红色
			this->LastPickedActor->GetProperty()->SetDiffuse(1.0);
			this->LastPickedActor->GetProperty()->SetSpecular(0.0);
		}

		// Forward events
		vtkInteractorStyleTrackballCamera::OnLeftButtonDown();
	}

private:
	vtkActor    *LastPickedActor;
	vtkProperty *LastPickedProperty;
};

vtkStandardNewMacro(PropPickerInteractorStyle);

int main(int argc, char *argv[])
{
	int numberOfSpheres = 10;
	if (argc > 1)
	{
		numberOfSpheres = atoi(argv[1]);
	}
	// A renderer and render window
	vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
	vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
	renderWindow->Render();
	// 设置窗口标题
	renderWindow->SetWindowName("PropPicker");
	renderWindow->AddRenderer(renderer);

	// An interactor
	vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New();
	renderWindowInteractor->SetRenderWindow(renderWindow);

	// Set the custom type to use for interaction.
	vtkSmartPointer<PropPickerInteractorStyle> style = vtkSmartPointer<PropPickerInteractorStyle>::New();
	style->SetDefaultRenderer(renderer);

	renderWindowInteractor->SetInteractorStyle(style);
	// 由于拾取以actor为单位，所以，要把一个对象存到一个actor中
	for (int i = 0; i < numberOfSpheres; ++i)
	{
		// 创建球对象数据
		vtkSmartPointer<vtkSphereSource> source = vtkSmartPointer<vtkSphereSource>::New();
		//生成随机坐标：x[-5,5] y[-5,5] z[-5,5]
		double x, y, z, radius;
		x = vtkMath::Random(-5, 5);
		y = vtkMath::Random(-5, 5);
		z = vtkMath::Random(-5, 5);
		// 生成随机半径
		radius = vtkMath::Random(.5, 1.0);
		source->SetRadius(radius);
		source->SetCenter(x, y, z);
		source->SetPhiResolution(11);
		source->SetThetaResolution(21);

		// 创建一个对象需要的 mapper
		vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
		mapper->SetInputConnection(source->GetOutputPort());
		// 创建一个对象需要的 actor
		vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
		actor->SetMapper(mapper);

		// 获取随机颜色
		double r, g, b;
		r = vtkMath::Random(.4, 1.0);
		g = vtkMath::Random(.4, 1.0);
		b = vtkMath::Random(.4, 1.0);
		actor->GetProperty()->SetDiffuseColor(r, g, b);
		actor->GetProperty()->SetDiffuse(.8);
		actor->GetProperty()->SetSpecular(.5);
		actor->GetProperty()->SetSpecularColor(1.0, 1.0, 1.0);
		actor->GetProperty()->SetSpecularPower(30.0);
	    // 将对象添加到renderer
		renderer->AddActor(actor);
	}

	renderer->SetBackground(1.0, 1.0, 1.0);// 白色背景

	// Render and interact
	renderWindow->Render();
	renderWindowInteractor->Initialize();
	renderWindowInteractor->Start();

	return EXIT_SUCCESS;
}

FIG exemplary dynamic effects