[vtkusers] Problem with color and shading when rendering vtkimagedata

[shadab anwar]

Hey amigos,

VTK noob here!

I facing a few problems while rendering vtkimagedata. The code snippet as
follows,


int X =4, Y=4, Z=4;

imageData->SetDimensions(X,Y,Z);

imageData->SetSpacing(1,1,1);

imageData->AllocateScalars(VTK_INT,1);



for (int k = 0; k < Z ; k++)

{

for (int j = 0; j < Y ; j++)

{

for (int i = 0; i < X ; i++)

{

int* voxel =
static_cast<int*>(imageData->GetScalarPointer(i, j, k));

voxel[0] = 10;


}

}

}


for (int i=2;i!=-1;i--)

{

int* voxel = static_cast<int*>(imageData->GetScalarPointer(2,i,i));

voxel[0]=0;

}


mapper->SetBlendModeToComposite();

mapper->SetRequestedRenderModeToRayCast();

mapper->SetInputData(imageData);

compositeOpacity->AddPoint(10,1);

color->AddRGBPoint(10,1,0,0);

compositeOpacity->AddPoint(0,0);

color->AddRGBPoint(0,0,0, 0);

volumeProperty->SetAmbient(0.3);

volumeProperty->SetDiffuse(0.4);

volumeProperty->SetSpecular(0.8);

volumeProperty->SetInterpolationType(0);

volumeProperty->ShadeOn();

volumeProperty->SetColor(color);

volumeProperty->SetScalarOpacity(compositeOpacity);

renderer->SetBackground(0.5, 0.5, 0.5);

volume->SetMapper(mapper);

volume->SetProperty(volumeProperty);

renderer->AddViewProp(volume);

I am getting the below results,


[image: image for forum.jpg] [image: image for forum2.jpg]
[image: image for forum3.jpg]


It can be seen that everytime I rotate my image I don't get a proper
shading and color for the object. I have tried changing the lightining
properties and shading properties but no sucess.

I would be really thankful if anyone could help me.


Just for your information I am mechanical engineering with a bit of
programming knowledge, so if my question is irrattional please forgive
me.




Best,

Shadab