Text Marker spacing is disproportionately large for small text

[rr-tom-noble]

Version:
humble binary (ros-humble-rviz2 11.2.16-1jammy.20250114.194245 via apt)

Issue:

See attached screenshots. The first shows a Text Marker of scale 1. The one after shows the same marker with a single space character added, which also seems to display reasonably:

The following images show the text with a scale of 0.01. The space character (which is still just a single space, no changes made to the text content) ends up comically large compared to the rest of the text:

Desired Solution:

Spaces in text should also scale down with the text size. My feeling is that it may be using fixed size spacing (e.g. size 1 spacing regardless of scale). This desired solution is also the default behaviour in ROS1, so there may have been a fix already that just needs porting to ROS2

[rr-tom-noble]

Ah I think I might've found the issue. Looks like scale.x is now used to control spacing?

rviz/rviz_default_plugins/src/rviz_default_plugins/displays/marker/markers/text_view_facing_marker.cpp

Lines 88 to 90 in dd6e968

	if (new_message->scale.x != 0.0) {
	text_->setSpaceWidth(new_message->scale.x);
	}

Edit: Confirmed to work by setting scale.x to scale.z

[rr-tom-noble]

Leaving this open as I'm unsure if there's a wiki page similar to https://wiki.ros.org/rviz/DisplayTypes/Marker (which is ROS1, but is the only result I get). Is there an equivalent, and does it need updating to reflect this field? Happy to raise a PR if so, otherwise happy to close.

[audrow]

If anyone can do this, please port into the ROS 2 Rviz docs.