<![CDATA[Need help on Quaternion.lookAt (NaN output)]]>https://doc.qt.io/qt-6/qml-qtquick3d-quaternion.html#lookAt-method

For the following arguments:

Quaternion.lookAt(
  Qt.vector3d(0.47212299704551697, -0.05714830011129379, -0.03842129930853844), 
  Qt.vector3d(0.0174984410405159, -0.1452823281288147, -0.038421452045440674), 
  Qt.vector3d(-0.9816991090774536, -0.19043900072574615, 0), 
  Qt.vector3d(0, 1, 0)
)

The output is a NaN quaternion? What's the issue here?

My understanding is lookAt calculates the rotation of the forwardDirection vector of an obj at sourcePosition to the other obj at targetPosition, so that forward after rotation aligns to target - source, and tries to keep upDirection close to the positive Y axis. Is this correct?

]]>https://forum.qt.io/topic/164140/need-help-on-quaternion.lookat-nan-outputRSS for NodeMon, 20 Apr 2026 01:00:41 GMTThu, 22 Jan 2026 02:12:40 GMT60<![CDATA[Reply to Need help on Quaternion.lookAt (NaN output) on Fri, 13 Feb 2026 01:43:43 GMT]]>Almost forgot to paste the qtbug: https://qt-project.atlassian.net/browse/QTBUG-143886
Seems they put it to Critical P1.

]]>https://forum.qt.io/post/836205https://forum.qt.io/post/836205Fri, 13 Feb 2026 01:43:43 GMT<![CDATA[Reply to Need help on Quaternion.lookAt (NaN output) on Wed, 04 Feb 2026 06:52:18 GMT]]>@KH-219Design Thanks for the reply, I do believe it's an account problem. I will send email and see what we can do about it.

]]>https://forum.qt.io/post/835998https://forum.qt.io/post/835998Wed, 04 Feb 2026 06:52:18 GMT<![CDATA[Reply to Need help on Quaternion.lookAt (NaN output) on Tue, 03 Feb 2026 16:20:30 GMT]]>There was a forum thread not too long ago about "unable to create bug report".

https://forum.qt.io/topic/163873/unable-to-comment-create-bug-reports-on-jira

The main take-away seems to be:

(I would guess that is still the standing advice?)

]]>https://forum.qt.io/post/835985https://forum.qt.io/post/835985Tue, 03 Feb 2026 16:20:30 GMT<![CDATA[Reply to Need help on Quaternion.lookAt (NaN output) on Tue, 03 Feb 2026 01:18:18 GMT]]>@SGaist Just had a look to the post.
Login is fine, Qt email and Atlassian email matches, I can see the issues on bug tracker.
However the "Create" button still won't work.
Plus I can't access the account profile page, it says:

This page has restricted content
This page has restrictions that limit who can view it. Try going back home or asking a workspace admin for viewing permission.
]]>https://forum.qt.io/post/835966https://forum.qt.io/post/835966Tue, 03 Feb 2026 01:18:18 GMT<![CDATA[Reply to Need help on Quaternion.lookAt (NaN output) on Mon, 02 Feb 2026 12:20:08 GMT]]>@FishBoneEK Hi,

Did you already check this pinned post ?

It might help you sort out your bug tracker issue.

]]>https://forum.qt.io/post/835950https://forum.qt.io/post/835950Mon, 02 Feb 2026 12:20:08 GMT<![CDATA[Reply to Need help on Quaternion.lookAt (NaN output) on Sun, 01 Feb 2026 06:49:04 GMT]]>@Jonas-Karlsson Thanks for the reply!
However I cannot file a bug report on the Bug Tracker (the "Create" button won't respond).
It would be nice if you would report it instead of me.

P.S. The bug in the bug tracker, pretty ironic?

Thanks!

]]>https://forum.qt.io/post/835912https://forum.qt.io/post/835912Sun, 01 Feb 2026 06:49:04 GMT<![CDATA[Reply to Need help on Quaternion.lookAt (NaN output) on Tue, 27 Jan 2026 14:49:28 GMT]]>After a quick glance at the Qt source code it seems like this is a bug so please feel free to report it.

]]>https://forum.qt.io/post/835765https://forum.qt.io/post/835765Tue, 27 Jan 2026 14:49:28 GMT