vtkimageSlice has a setOpacity value of 1

[ondaa]

Bug description

Hi, I'm using the 2D label map painting function.

I ran it by applying 1 to the setOpacity function of ImageSlice, and I tried to paint wideget, but I couldn't find any traces of painting. And when I applied 0.999 as the opacity value, I saw it.

Is this an issue? Example looked at the following.

https://kitware.github.io/vtk-js/examples/PaintWidget.html

Steps to reproduce

...
layerColorFun.addRGBPoint(1, 128 / 256, 174 / 256, 128 / 256);
layerPiecewiseFun.addPoint(0, 0);
layerPiecewiseFun.addPoint(1, 1.0);

layerActor.getProperty().setRGBTransferFunction(0, layerColorFun);  
layerActor.getProperty().setPiecewiseFunction(0, layerPiecewiseFun);
layerActor.getProperty().setOpacity(1); // <-- this setting

...

Detailed Behavior

No response

Expected Behavior

setOpacity(1.0) or setOpacity(1) show painting.

Environment

• vtk.js version: 32.7.0
• Browsers: Chrome
• OS: Windows

[finetjul]

I tried to modify the PaintWidget example from
labelMap.actor.getProperty().setOpacity(0.5);
to
labelMap.actor.getProperty().setOpacity(1);
and the labelmap still renders fine.

Can you please provide a non working example ?

[ondaa]

Thank you for the reaction.

The code is no different from the example. Look at this video.

If the opacity value is 1, the label map color is not visible, but if it is less than 1 visible.
(update is setOpacity method)

Viewer.Spread.-.Chrome.2024-11-18.10-12-03.mp4

[finetjul]

can you reproduce the issue within the example ?