[Bug] ResliceCursorWidgetExample is obscured by axis colors

[martinerler]

Bug description

The ResliceCursorWidget is obscured by its axis colors.

Steps to reproduce

• View the example ResliceCursorWidget at the website
• Or start the example ResliceCursorWidget locally at Version v34.11.2

Detailed Behavior

The image content is not visible, unless you change the axis rotation in one of the three views.
Last Known Working Version is 34.8.0.
I noticed that the problem came up between v34.8.0 and v34.8.1.

v34.8.0...v34.8.1

Expected Behavior

The image content should be visible and not covered or distracted by other colors.

Environment

• vtk.js version: 34.8.1
• Browsers: Chrome Version 140.0.7339.128 and Firefox 143.0
• OS: Win 11

Last Known Working Version: 34.8.0

[finetjul]

The issue is indeed with the glyph mapper shift + scale parameters

[daker]

maybe it does impact the PolyDataNormals examples also ? https://kitware.github.io/vtk-js/examples/PolyDataNormals/index.html

[martinerler]

maybe it does impact the PolyDataNormals examples also ? https://kitware.github.io/vtk-js/examples/PolyDataNormals/index.html

I'm not familiar with the PolyDataNormals example in detail, but it does not seem to be obscured by other colors.

[martinerler]

Thank you for analysing the problem and assigning the issue :)

[1009058470]

The issue is indeed with the glyph mapper shift + scale parameters

what is this and where i can found

[finetjul]

The issue is indeed with the glyph mapper shift + scale parameters

what is this and where i can found

The issue comes from this commit:
cc07c84

I unfortunately do not have spare time to look at this. @sankhesh ?

[sankhesh]

I'm planning to look into this issue in the coming few weeks. I'll post an update when I have a solution.

[1009058470]

I'm planning to look into this issue in the coming few weeks. I'll post an update when I have a solution.

i want to have a try but i do not know hwo vtkjs work?is there any doc for how vtkjs work?

[martinerler]

I found a way to deside, if the shift and scale in Glyph3DMapper should be used. This heuristic checks if it's a widget and omit shift and scale for that.

const numPoints = pts.getNumberOfPoints();
const isLikelyWidget = numPoints < 100; // Most widget reps have very few points (lines, spheres, etc.)
const shouldApplyShiftScale = useShiftAndScale && !isLikelyWidget;

Is that kind of heuristic good?
Or should we fix the problem in an other way?