<font size="2"><font face="verdana,sans-serif">I have found a solution, following a suggestion here: <a href="http://vtk.1045678.n5.nabble.com/Updating-color-transfer-function-for-GPU-volume-td3312776.html">http://vtk.1045678.n5.nabble.com/Updating-color-transfer-function-for-GPU-volume-td3312776.html</a></font></font><div>
<font size="2"><font face="verdana,sans-serif">I modified the code to following:</font></font></div><div><font size="2"><font face="verdana,sans-serif"><div><br></div><div>void MainWindow::on_TF_chosen(QAction *action)</div>
<div>{</div><div> if (volume) //volume is loaded and set up</div><div> {</div><div> volume->SetProperty( tf[action->data().toInt()] );</div><div> volume->GetProperty()->GetRGBTransferFunction()->Modified();</div>
<div> volume->GetProperty()->GetScalarOpacity()->Modified();</div><div> vis->GetRenderWindow()->Render();</div><div> }</div><div>}</div><div><br></div><div>That is, I just added calls to modified() to color and opacity transfer functions.</div>
</font></font><br><div class="gmail_quote">2011/2/7 Dženan Zukić <span dir="ltr"><<a href="mailto:dzenanz@gmail.com">dzenanz@gmail.com</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<font size="2"><font face="verdana,sans-serif">Hi all,</font></font><div><font size="2"><font face="verdana,sans-serif"><br></font></font></div><div><font size="2"><font face="verdana,sans-serif">I have the following menu handler:</font></font></div>
<div><font size="2"><div style="font-family:verdana, sans-serif"><br></div><div><font face="'courier new', monospace">void MainWindow::on_TF_chosen(QAction *action)</font></div><div><font face="'courier new', monospace">{</font></div>
<div><font face="'courier new', monospace"> if (volume) //volume is loaded and set up</font></div><div><font face="'courier new', monospace"> {</font></div>
<div><font face="'courier new', monospace"> volume->SetProperty( tf[action->data().toInt()] );</font></div><div><font face="'courier new', monospace"> vis->GetRenderWindow()->Render();</font></div>
<div><font face="'courier new', monospace"> }</font></div><div><font face="'courier new', monospace">}</font></div><div style="font-family:verdana, sans-serif">
<br></div><div><font face="'courier new', monospace">tf</font><span style="font-family:verdana, sans-serif"> is an array of </span><font face="'courier new', monospace">vtkVolumeProperty*</font><font face="verdana, sans-serif">s, containing combinations of color and opacity transfer functions. However, when transfer function is changed with this procedure, the result is not what I expect: transfer functions are either not changed, or they are changed to something I didn't specify.</font></div>
<div><font face="verdana, sans-serif"><br></font></div><div><font face="verdana, sans-serif">Is there some call missing here, something like "UpdateTransferFunctions"?</font></div>
<div><font face="verdana, sans-serif"><br></font></div><div><font face="verdana, sans-serif">This is the code from form constructor:</font></div><div><font face="verdana, sans-serif"><br>
</font></div><div><div><div><font face="'courier new', monospace">//manually create transfer functions</font></div><div><font face="'courier new', monospace">tf[0] = vtkVolumeProperty::New();</font></div>
<div><font face="'courier new', monospace">vtkPiecewiseFunction *opacityFun0 = vtkPiecewiseFunction::New();</font></div><div><font face="'courier new', monospace">tf[0]->SetScalarOpacity( opacityFun0 );</font></div>
<div><font face="'courier new', monospace">opacityFun0->AddPoint(0, 0);</font></div><div><font face="'courier new', monospace">opacityFun0->AddPoint(255, 0 );</font></div>
<div><font face="'courier new', monospace">tf[0]->ShadeOn();</font></div><div><font face="'courier new', monospace">tf[0]->SetScalarOpacityUnitDistance(0.8919);</font></div>
<div><font face="'courier new', monospace"><br></font></div><div><font face="'courier new', monospace">tf[1] = vtkVolumeProperty::New();</font></div><div><font face="'courier new', monospace">vtkColorTransferFunction *colorFun1 = vtkColorTransferFunction::New();</font></div>
<div><font face="'courier new', monospace">vtkPiecewiseFunction *opacityFun1 = vtkPiecewiseFunction::New();</font></div><div><font face="'courier new', monospace">tf[1]->SetColor( colorFun1 );</font></div>
<div><font face="'courier new', monospace">tf[1]->SetScalarOpacity( opacityFun1 );</font></div><div><font face="'courier new', monospace">tf[1]->SetInterpolationTypeToLinear();</font></div>
<div><font face="'courier new', monospace">colorFun1->AddRGBPoint( 0, .55, .75, .85 );</font></div><div><font face="'courier new', monospace">colorFun1->AddRGBPoint( 80, .88, .60, .29 );</font></div>
<div><font face="'courier new', monospace">opacityFun1->AddPoint(0, 0);</font></div><div><font face="'courier new', monospace">opacityFun1->AddPoint(80, .5 );</font></div>
<div><font face="'courier new', monospace">tf[1]->ShadeOn();</font></div><div><font face="'courier new', monospace">tf[1]->SetScalarOpacityUnitDistance(0.8919);</font></div>
<div><font face="'courier new', monospace"><br></font></div><div><font face="'courier new', monospace">tf[2] = vtkVolumeProperty::New();</font></div><div><font face="'courier new', monospace">vtkColorTransferFunction *colorFun2 = vtkColorTransferFunction::New();</font></div>
<div><font face="'courier new', monospace">vtkPiecewiseFunction *opacityFun2 = vtkPiecewiseFunction::New();</font></div><div><font face="'courier new', monospace">tf[2]->SetColor( colorFun2 );</font></div>
<div><font face="'courier new', monospace">tf[2]->SetScalarOpacity( opacityFun2 );</font></div><div><font face="'courier new', monospace">tf[2]->SetInterpolationTypeToLinear();</font></div>
<div><font face="'courier new', monospace">colorFun2->AddRGBPoint( 0, .55, .9, .5 );</font></div><div><font face="'courier new', monospace">colorFun2->AddRGBPoint( 160, .88, .1, .1 );</font></div>
<div><font face="'courier new', monospace">opacityFun2->AddPoint(0, 0);</font></div><div><font face="'courier new', monospace">opacityFun2->AddPoint(160, .6 );</font></div>
<div><font face="'courier new', monospace">tf[2]->ShadeOn();</font></div><div><font face="'courier new', monospace">tf[2]->SetScalarOpacityUnitDistance(0.8919);</font></div>
</div><div style="font-family:verdana, sans-serif"><br></div><div style="font-family:verdana, sans-serif">Thanks,</div><div style="font-family:verdana, sans-serif">Dženan</div></div></font></div>
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