vtkPlane和vtkPlaneSource

最新推荐文章于 2025-05-25 07:29:36 发布

转载

最新推荐文章于 2025-05-25 07:29:36 发布 · 985 阅读

1 ·

CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/phoenixdsg/p/6241318.html

文章标签：

#c/c++

本文详细介绍了vtkPlane类的成员函数及其用途，包括点法式隐函数方程、投影计算等。接着讲解了vtkPlanes如何处理一组平面的隐函数和梯度，以及其在相机视锥体和平面定义中的应用。vtkAppendPolyData用于合并多个多边形数据集，而vtkGlyph3D则将几何符号复制到输入点上，并能根据矢量和标量数据调整。最后，文章阐述了vtkPlaneSource如何创建平面上的四边形阵列，并提供了调整平面位置和方向的方法。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1、vtkPlane

vtkPlane provides methods for various plane computations. These include projecting points onto a plane, evaluating the plane equation, and returning plane normal. vtkPlane is a concrete implementation of the abstract class vtkImplicitFunction.

成员函数：void EvaluateFunction（double x[3]）、void EvaluateFunction（double x,double y,double z)用于估算点x[3]是否位于平面上、平面前或平面后（法线方向为前），它是从抽象类vtkImplicitFunction继承而来，在基类中它是一个纯虚函数。
　　　　 void EvaluateGradient (double x[3], double g[3])用于估算点x[3]处函数倾斜度
void vtkPlane::SetNormal（double x[3]）、void vtkPlane::SetNormal（double x,double y,double z) Set/get平面法向量.平面是由“点”和“法向量”定义的。
void Set/GetOrigin（double x[3]）与SetNormal用法类似。
void vtkPlane::Push(double distance)该函数可以将平面沿着法线方向移动distance距离
在成员函数中还定义了点、矢量向某个平面投影的功能函数，如ProjectPoint、ProjectVector等。

隐函数的数学表达式为F(x,y,z)=w，平面的隐函数方程有点法式和一般式。在vtkPlane中采用的是点法式隐函数
点法式平面隐函数方程为：A(x-x0)+B(y-y0)+C(z-z0)=w, (A,B,C)为平面法向量，即vtkPlane中的Normal，(x0,y0,z0)为平面上一点，即vtkPlane中的Origin。
平面的一般式方程为：Ax+By+Cz=w

EvaluateFunction的源代码如下：　　

double vtkPlane::EvaluateFunction(double x[3])
{
  return ( this->Normal[0]*(x[0]-this->Origin[0]) +
           this->Normal[1]*(x[1]-this->Origin[1]) +
           this->Normal[2]*(x[2]-this->Origin[2]) );
}

Examples:

vtkPlane (Examples)

Tests:

vtkPlane (Tests)

vtkPlane.h源代码：

#include "vtkCommonDataModelModule.h" // For export macro
#include "vtkImplicitFunction.h"

class VTKCOMMONDATAMODEL_EXPORT vtkPlane : public vtkImplicitFunction
{
public:
  // Description
  // Construct plane passing through origin and normal to z-axis.
  static vtkPlane *New();

  vtkTypeMacro(vtkPlane,vtkImplicitFunction);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description
  // Evaluate plane equation for point x[3].
  double EvaluateFunction(double x[3]);
  double EvaluateFunction(double x, double y, double z)
    {
     
     return this->vtkImplicitFunction::EvaluateFunction(x, y, z); } ;

  // Description
  // Evaluate function gradient at point x[3].
  void EvaluateGradient(double x[3], double g[3]);

  // Description:
  // Set/get plane normal. Plane is defined by point and normal.
  vtkSetVector3Macro(Normal,double);
  vtkGetVectorMacro(Normal,double,3);

  // Description:
  // Set/get point through which plane passes. Plane is defined by point
  // and normal.
  vtkSetVector3Macro(Origin,double);
  vtkGetVectorMacro(Origin,double,3);

  // Description:
  // Translate the plane in the direction of the normal by the
  // distance specified.  Negative values move the plane in the
  // opposite direction.
  void Push(double distance);

  // Description
  // Project a point x onto plane defined by origin and normal. The
  // projected point is returned in xproj. NOTE : normal assumed to
  // have magnitude 1.
  static void ProjectPoint(double x[3], double origin[3], double normal[3],
                           double xproj[3]);
  void ProjectPoint(double x[3], double xproj[3]);

  // Description
  // Project a vector v onto plane defined by origin and normal. The
  // projected vector is returned in vproj.
  static void ProjectVector(double v[3], double origin[3], double normal[3],
                           double vproj[3]);
  void ProjectVector(double v[3], double vproj[3]);

  // Description
  // Project a point x onto plane defined by origin and normal. The
  // projected point is returned in xproj. NOTE : normal does NOT have to
  // have magnitude 1.
  static void GeneralizedProjectPoint(double x[3], double origin[3],
                                      double normal[3], double xproj[3]);
  void GeneralizedProjectPoint(double x[3], double xproj[3]);


  // Description:
  // Quick evaluation of plane equation n(x-origin)=0.
  static double Evaluate(double normal[3], double origin[3], double x[3]);

  // Description:
  // Return the distance of a point x to a plane defined by n(x-p0) = 0. The
  // normal n[3] must be magnitude=1.
  static double DistanceToPlane(double x[3], double n[3], double p0[3]);
  double DistanceToPlane(double x[3]);

  // Description:
  // Given a line defined by the two points p1,p2; and a plane defined by the
  // normal n and point p0, compute an intersection. The parametric
  // coordinate along the line is returned in t, and the coordinates of
  // intersection are returned in x. A zero is returned if the plane and line
  // do not intersect between (0<=t<=1). If the plane and line are parallel,
  // zero is returned and t is set to VTK_LARGE_DOUBLE.
  static int IntersectWithLine(double p1[3], double p2[3], double n[3],
                               double p0[3], double& t, double x[3]);
  int IntersectWithLine(double p1[3], double p2[3],