[vtkusers] Re: Fw: point rendering

[Jan Fransens]

Hi,

using only the ambient light results in a completely white, unshaded point 
cloud (I did not specify per_point colors). I also tried adding some lights, 
but the shading results seemed quite strange...

Jan

----- Original Message ----- 
From: "Goodwin Lawlor" <goodwin.lawlor at ucd.ie>
To: <vtkusers at public.kitware.com>
Sent: Wednesday, April 05, 2006 3:52 PM
Subject: [vtkusers] Re: Fw: point rendering


> Jan Fransens wrote:
>> Hi,
>>  I am trying to render a point cloud of 3d coordinates with associated 
>> normals. However, during rendering, points with a normal facing away are 
>> rendered completely black. Points with front facing normals are rendered 
>> fine.
>>  pActor1->GetProperty()->SetPointSize(2.0);
>> pActor1->GetProperty()->SetColor(1.0,1.0,1.0);
>> pActor1->GetProperty()->SetRepresentationToPoints();   // |_rendering 
>> behaviour doesn't change
>> pActor1->SetBackfaceProperty(pActor1->GetProperty());// |
>>
>> pRenWin->GetRenderer()->TwoSidedLightingOn(); // same result
>> pRenWin->GetRenderer()->AddActor(pActor1);
>> pRenWin->GetRenderer()->ResetCamera();
>> pRenWin->show();
>>  Does anyone know what causes this problem (I'm using Vtk 4.2)
>>  Many thanks,
>>  Jan
>
> Hi Jan,
>
> Your points are being shaded with the backfacing points getting no 
> light... try:
>
> pActor1->GetProperty()->SetDiffuse(0);
> pActor1->GetProperty()->SetAmbient(1);
>
> You wont need the BackfaceProperty to be set.
>
> hth
>
> Goodwin
>
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