[Bug] Can't change vtkTextActor color

[chrishavlin]

Bug description

Can't seem to change the color of vtkTextActor.

Doing the following does not change the text color, it's always black (full codesandbox linked below):

const actor = vtkTextActor.newInstance();
actor.getProperty().setFontColor(255,255,255); // doctsring says 0-255 for RGB values

also tried actor.getProperty().setColor(), same behavior. Is there another way I should be setting the text color?

Steps to reproduce

here's a modification of the textActor example with RGB inputs:

https://codesandbox.io/p/devbox/vtkjs-vector-text-forked-3dkx24?workspaceId=ws_7cQK1iKXMw8NPVoWmC7hHm

Detailed Behavior

No response

Expected Behavior

Should be able to set the color of a vtkTextActor

Environment

• vtk.js version: 35.4.0
• Browsers: firefox
• OS: macos

[jourdain]

Docstring should say between 0-1, not 0-255.

Playing with your example, it is working

[chrishavlin]

oh hmm... should have mentioned I did try values in the range 0-1 too. Still not seeing any changes with my example, it's always black. Tried other browsers too (firefox, safari, chrome). I did just upgrade to the latest macos (26.3.1), any reason that might impact this? I can try on another os later...

[chrishavlin]

oh wait. It changes color if I change one of the other inputs after updating the color value

[chrishavlin]

so

const actor = vtkTextActor.newInstance();
actor.getProperty().setFontColor(1.,1.,1.);
actor.setInput("Hello World!");

works as expected, but setting font color after the input does not update the color:

const actor = vtkTextActor.newInstance();
actor.setInput("Hello World!");
actor.getProperty().setFontColor(1.,1.,1.);

Is that expected behavior?

[jourdain]

The mapper should detect that the property has changed. So this is a bug, but you can call .modified() on the actor as a work around. FYI @daker

[daker]

Sure i will make a fix

[daker]

@chrishavlin I've submitted a PR and updated the example, you'll get the fix once it's reviewed and merged.