5.1 3D坐标轴(vtkCubeAxesActor)
5.1.1 对象接口说明
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SetXAxisLabelVisibility(vtkTypeBool) SetYAxisLabelVisibility(vtkTypeBool) SetZAxisLabelVisibility(vtkTypeBool) |
设置x、y、z轴刻度标签是否显示 |
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SetXAxisTickVisibility(vtkTypeBool) SetYAxisTickVisibility(vtkTypeBool) SetZAxisTickVisibility(vtkTypeBool) |
设置x、y、z轴刻度是否显示 |
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SetXAxisMinorTickVisibility(vtkTypeBool) SetYAxisMinorTickVisibility(vtkTypeBool) SetZAxisMinorTickVisibility(vtkTypeBool) |
设置x、y、z轴次刻度是否显示 |
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SetDrawXGridlines(vtkTypeBool) SetDrawYGridlines(vtkTypeBool) SetDrawZGridlines(vtkTypeBool) |
设置是否绘制x、y、z轴的网格线 |
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SetDrawXInnerGridlines(vtkTypeBool) SetDrawYInnerGridlines(vtkTypeBool) SetDrawZInnerGridlines(vtkTypeBool) |
设置是否绘制x、y、z轴的网格线的内部网格线 |
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SetDrawXGridpolys(vtkTypeBool) SetDrawYGridpolys(vtkTypeBool) SetDrawZGridpolys(vtkTypeBool) |
设置是否绘制x、y、z轴的网格线的内部网格面 |
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SetLabelScaling(bool，int，int，int) |
设置刻度标签的显示样式，假设坐标轴的值范围为0-200000，当参数1为false时，刻度标签按0-200000显示；参数1为true时，按0-200显示 |
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SetXAxisRange(double,double) SetYAxisRange(double,double) SetZAxisRange(double,double) |
设置x、y、z轴值的范围 |
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SetScreenSize (double screenSize) |
设置标题和标签文本的屏幕大小。默认值为10.0。 |
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SetLabelOffset (double offset) |
指定标签与轴之间的距离。默认值为20.0。 |
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SetTitleOffset(double) |
设置标题和刻度标签之间的距离。默认为20.0 |
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SetCamera(vtkCamera *) |
设置相机，以执行缩放。一般是将当前render的相机设置给坐标轴。 |
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SetFlyMode(int) |
指定一种模式来控制轴的绘制方式 enum FlyMode { VTK_FLY_OUTER_EDGES = 0,//外边缘 VTK_FLY_CLOSEST_TRIAD = 1,//最近位置 VTK_FLY_FURTHEST_TRIAD = 2,//最远位置 VTK_FLY_STATIC_TRIAD = 3,//静态最近位置，不随摄像头动而跳变位置。 VTK_FLY_STATIC_EDGES = 4 //静态所有外边缘位置，不随摄像头动而跳变位置。 }; |
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SetXTitle (const char *) SetYTitle (const char *) SetZTitle (const char *) |
设置x、y、z轴的标题 |
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SetTickLocation |
设置刻度线显示的位置 enum TickLocation { VTK_TICKS_INSIDE = 0,//内部 VTK_TICKS_OUTSIDE = 1,//外部 VTK_TICKS_BOTH = 2//两侧 }; |
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SetInertia (int) |
设置惯性因子，该惯性因子控制轴切换位置的频率（从一个轴跳到另一个轴），范围为1到VTK_INT_MAX。默认值是1 |
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SetCornerOffset (double) |
指定一个偏移量值，以便从轴连接的角“拉回”轴，以避免轴标签重叠。默认值是0 |
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SetXAxisVisibility(vtkTypeBool) SetYAxisVisibility(vtkTypeBool) SetZAxisVisibility(vtkTypeBool) |
设置x、y、z轴的显示状态。 |
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SetGridLineLocation |
指定网格线呈现的样式 enum GridVisibility { VTK_GRID_LINES_ALL = 0,//呈现所有网格线 VTK_GRID_LINES_CLOSEST = 1,//呈现最近的三个轴的网格线 VTK_GRID_LINES_FURTHEST = 2//呈现最远的三个轴的网格线 }; |
5.1.2 代码实现
1 void ESAxes::create()
2 {
3 m_cubeAxesActor = vtkSmartPointer<vtkCubeAxesActor>::New();
4 m_cubeAxesActor->SetCamera(m_pRender->GetActiveCamera());
5 //
6 //轴的设置
7 //设置x、y、z轴的起始和终止值
8 m_cubeAxesActor->SetXAxisRange(0, 200000);
9 m_cubeAxesActor->SetYAxisRange(0, 200000);
10 m_cubeAxesActor->SetZAxisRange(0, 200000);
11 //设置坐标轴线的宽度
12 m_cubeAxesActor->GetXAxesLinesProperty()->SetLineWidth(0.5);
13 m_cubeAxesActor->GetYAxesLinesProperty()->SetLineWidth(0.5);
14 m_cubeAxesActor->GetZAxesLinesProperty()->SetLineWidth(0.5);
15 //设置标题和标签文本的屏幕大小。默认值为10.0。
16 m_cubeAxesActor->SetScreenSize(6);
17 //指定标签与轴之间的距离。默认值为20.0。
18 m_cubeAxesActor->SetLabelOffset(5);
19 //显示坐标轴
20 m_cubeAxesActor->SetVisibility(true);
21 //指定一种模式来控制轴的绘制方式
22 m_cubeAxesActor->SetFlyMode(0);
23 //设置惯性因子，该惯性因子控制轴切换位置的频率（从一个轴跳到另一个轴）
24 //m_cubeAxesActor->SetInertia(1);
25 //
26 //网格设置
27 //开启x、y、z轴的网格线绘制
28 m_cubeAxesActor->DrawXGridlinesOn();
29 m_cubeAxesActor->DrawYGridlinesOn();
30 m_cubeAxesActor->DrawZGridlinesOn();
31 //设置x、y、z轴的内部网格线不绘制
32 m_cubeAxesActor->SetDrawXInnerGridlines(false);
33 m_cubeAxesActor->SetDrawYInnerGridlines(false);
34 m_cubeAxesActor->SetDrawZInnerGridlines(false);
35 //设置x、y、z轴网格线的颜色
36 m_cubeAxesActor->GetXAxesGridlinesProperty()->SetColor(0.5, 0.5, 0.5);
37 m_cubeAxesActor->GetYAxesGridlinesProperty()->SetColor(0.5, 0.5, 0.5);
38 m_cubeAxesActor->GetZAxesGridlinesProperty()->SetColor(0.5, 0.5, 0.5);
39 //指定网格线呈现的样式
40 m_cubeAxesActor->SetGridLineLocation(2);
41 //
42 //刻度的设置
43 //不显示x、y、z轴的次刻度
44 m_cubeAxesActor->XAxisMinorTickVisibilityOff();
45 m_cubeAxesActor->YAxisMinorTickVisibilityOff();
46 m_cubeAxesActor->ZAxisMinorTickVisibilityOff();
47 //设置刻度标签的显示方式(参数1为false，刻度标签按0-200000显示；为true时，按0-200显示)
48 m_cubeAxesActor->SetLabelScaling(false, 0, 0, 0);
49 //设置刻度线显示的位置(内部、外部、两侧)
50 m_cubeAxesActor->SetTickLocation(1);
51 //
52 m_pRender->AddActor(m_cubeAxesActor);
53 m_pRender->ResetCamera();
54 m_pRender->ResetCameraClippingRange();
55 m_pRenderWnd->Render();
56 }
5.1.3 扩展
5.1.3.1 显示问题-刻度与网格线分离
如下图：
较好的显示效果应该为：1处有网格线，2和3处有刻度标注。
出现该问题的原因：
（1）首先，vtkCubeAxesActor对象的构造函数中是分别为x、y、z三个方向都创建了4个vtkAxisActor对象，代码如下：
1 vtkCubeAxesActor::vtkCubeAxesActor() : vtkActor()
2 {
3 。。。
4 for (int i = 0; i < NUMBER_OF_ALIGNED_AXIS; i++)
5 {
6 this->XAxes[i] = vtkAxisActor::New();
7 this->XAxes[i]->SetTickVisibility(1);
8 this->XAxes[i]->SetMinorTicksVisible(1);
9 this->XAxes[i]->SetLabelVisibility(1);
10 this->XAxes[i]->SetTitleVisibility(1);
11 this->XAxes[i]->SetAxisTypeToX();
12 。。。
13
14 this->YAxes[i] = vtkAxisActor::New();
15 this->YAxes[i]->SetTickVisibility(1);
16 this->YAxes[i]->SetMinorTicksVisible(1);
17 this->YAxes[i]->SetLabelVisibility(1);
18 this->YAxes[i]->SetTitleVisibility(1);
19 this->YAxes[i]->SetAxisTypeToY();
20 this->YAxes[i]->SetAxisPosition(i);
21 this->YAxes[i]->SetAxisLinesProperty(this->YAxesLinesProperty);
22 this->YAxes[i]->SetGridlinesProperty(this->YAxesGridlinesProperty);
23 this->YAxes[i]->SetInnerGridlinesProperty(this->YAxesInnerGridlinesProperty);
24 。。。
25
26 this->ZAxes[i] = vtkAxisActor::New();
27 this->ZAxes[i]->SetTickVisibility(1);
28 this->ZAxes[i]->SetMinorTicksVisible(1);
29 this->ZAxes[i]->SetLabelVisibility(1);
30 this->ZAxes[i]->SetTitleVisibility(1);
31 this->ZAxes[i]->SetAxisTypeToZ();
32 。。。
33 。。。
34 。。。
35 }
NUMBER_OF_ALIGNED_AXIS = 4。
而针对指定网格线呈现的样式为VTK_GRID_LINES_FURTHEST时，x、y、z方向的都各只有一个vtkAxisActor会画网格线且不呈现刻度标注，代码如下：
1 void vtkCubeAxesActor::UpdateGridLineVisibility(int idx)
2 {
3 if( this->GridLineLocation != VTK_GRID_LINES_ALL &&
4 (this->DrawXGridlines || this->DrawYGridlines || this->DrawZGridlines) )
5 {
6 for(int i=0; i < NUMBER_OF_ALIGNED_AXIS; ++i)
7 {
8 this->XAxes[i]->SetDrawGridlines(0);
9 this->YAxes[i]->SetDrawGridlines(0);
10 this->ZAxes[i]->SetDrawGridlines(0);
11 this->XAxes[i]->SetDrawGridlinesOnly(0);
12 this->YAxes[i]->SetDrawGridlinesOnly(0);
13 this->ZAxes[i]->SetDrawGridlinesOnly(0);
14 }
15 int xId = vtkCubeAxesActorTriads[idx][0];
16 int yId = vtkCubeAxesActorTriads[idx][1];
17 int zId = vtkCubeAxesActorTriads[idx][2];
18 this->XAxes[xId]->SetDrawGridlines(this->DrawXGridlines);
19 this->YAxes[yId]->SetDrawGridlines(this->DrawYGridlines);
20 this->ZAxes[zId]->SetDrawGridlines(this->DrawZGridlines);
21 // Update axis render list
22 int id = 0;
23 if(this->NumberOfAxesX == 1)
24 {
25 id = this->RenderAxesX[this->NumberOfAxesX] = vtkCubeAxesActorTriads[idx][0];
26 this->XAxes[id]->SetDrawGridlinesOnly((this->RenderAxesX[0] != id) ? 1 : 0);
27 this->NumberOfAxesX += (this->RenderAxesX[0] != id) ? 1 : 0;
28 }
29 if(this->NumberOfAxesY == 1)
30 {
31 id = this->RenderAxesY[this->NumberOfAxesY] = vtkCubeAxesActorTriads[idx][1];
32 this->YAxes[id]->SetDrawGridlinesOnly((this->RenderAxesY[0] != id) ? 1 : 0);
33 this->NumberOfAxesY += (this->RenderAxesY[0] != id) ? 1 : 0;
34 }
35 if(this->NumberOfAxesZ == 1)
36 {
37 id = this->RenderAxesZ[this->NumberOfAxesZ] = vtkCubeAxesActorTriads[idx][2];
38 this->ZAxes[id]->SetDrawGridlinesOnly((this->RenderAxesZ[0] != id) ? 1 : 0);
39 this->NumberOfAxesZ += (this->RenderAxesZ[0] != id) ? 1 : 0;
40 }
41 }
42 }
网格线是由图中箭头所指的vtkAxisActor对象绘制出来的，我们可以从vtkAxisActor绘制网格线的代码中看到：
1 void vtkAxisActor::BuildAxisGridLines(
2 double p1[3], double p2[3], double localCoordSys[3][3])
3 {
4 。。。
5 // - Insert Gridlines points along the axis using the DeltaMajor vector
6 double nbIterationAsDouble = (axisLength - axisShift) / vtkMath::Norm(deltaVector);
7 int nbIteration = vtkMath::Floor(nbIterationAsDouble + 2 * FLT_EPSILON) + 1;
8 nbIteration = (nbIteration < VTK_MAX_TICKS) ? nbIteration : VTK_MAX_TICKS;
9 for (int nbTicks = 0; nbTicks < nbIteration; nbTicks++)
10 {
11 // Closest U
12 this->GridlinePts->InsertNextPoint(gridPointClosest);
13 this->GridlinePts->InsertNextPoint(gridPointU);
14 // Farest U
15 this->GridlinePts->InsertNextPoint(gridPointFarest);
16 this->GridlinePts->InsertNextPoint(gridPointU);
17 // Closest V
18 this->GridlinePts->InsertNextPoint(gridPointClosest);
19 this->GridlinePts->InsertNextPoint(gridPointV);
20 // Farest V
21 this->GridlinePts->InsertNextPoint(gridPointFarest);
22 this->GridlinePts->InsertNextPoint(gridPointV);
23 // PolyPoints
24 this->GridpolyPts->InsertNextPoint(gridPointClosest);
25 this->GridpolyPts->InsertNextPoint(gridPointU);
26 this->GridpolyPts->InsertNextPoint(gridPointFarest);
27 this->GridpolyPts->InsertNextPoint(gridPointV);
28 。。。
29 }
30 。。。
31 }
5.1.3.2 显示问题-次刻度的网格没有绘制
次刻度的网格之所以没有绘制，是因为在vtkAxisActor绘制网格的接口中没有实现绘制次刻度网格。若想绘制次刻度网格线，必须自己修改源码实现绘制次网格线的代码，修改源码显示次网格线的效果如下：
