Free Orbit Bug - Closer to a Fix?

[EricY_Design]

Fusion 360 Support Team,

Hi, I am new to these forums but have been using Fusion 360 as a replacement for T-Splines for some time now.

As a few others have posted before, the Free Orbit tool can have a bug where the camera follows an unintended path when cursor is left-dragged horizontally. I’m currently on Mac version 2.0.9930 and the problem remains unresolved since my trial on PC almost 3 years ago, I'm guessing due to it's elusive nature. Recently I did a little experimenting to try to understand the problem better and I think I've also spotted a pattern of its occurrence/disappearance, so I’m posting to share my findings. Hopefully these can help lead to a fix soon.

A screencast of the exact problem has been posted by @DreBz, please refer to:

https://forums.autodesk.com/t5/fusion-360-support/free-orbit-rotation-bug-with-bizarre-fix/m-p/94770...

More links at the bottom

What Seems to be Happening

Assuming current view’s camera is pointing towards the horizon, ground is horizontal in the view, an object is at the center of view, no camera pivot is set. Using spinning the object by left-dragging cursor to the right as an example:

1. As you begin to drag to the right, the view’s camera position gets translated fine - keeping same distance to the object; camera's heading is adjusted to point to the object fine too but there is also a clockwise twist (positive rotation along the lens-to-object axis) added for no reason, so the view begins to rotate counter-clockwise and the ground plane is no longer horizontal.
2. As the cursor is further dragged to the right, #1 repeats but right, in relation to this now rotated view, is no longer parallel to the ground plane, so the orbit is no longer planar!
3. #2 repeats as you keep dragging to the right and the camera’s path would actually run curving around a sphere even though the cursor has only moved to the right! If one is used to free orbit in other CAD apps it would be immediately obvious, like how you can “feel” a skid in a racing game.

This extra twist of the camera is the bug!

Vertical Free Orbit Not Affected

Interestingly if you're to left-drag the cursor to the top or bottom (tumble the object), the camera orbits just fine without any twisting weirdness. So maybe something in the shared code differentiating Free Orbit and Constrained Orbit is causing the problem, as Free Orbit has no need to make this distinction. (Clue?)

3DConnexion Also Affected

Also interesting is that orbiting on my 3DConnexion mouse can also show the same bug, occurring at exactly the same conditions as when using regular mouse. Could what @Anonymous and @XDGFX described be the same bug?

https://forums.autodesk.com/t5/fusion-360-support/3dconnexion-spacemouse-horizon-lock-constrain-orbit-missing/m-p/9697278/highlight/true#M97643

https://forums.autodesk.com/t5/fusion-360-support/3d-connexion-spacemouse-spin-also-rotates/m-p/9096200/highlight/true#M69349

Is it possible that some requests for a "horizon lock" feature on 3DConnexion is actually due to this very bug? 3DConnexion Control Panel already allows for of enabling/disabling/dominant axii...

Why The Bug Comes and Goes

Basically it is as if Free Orbit switches back and forth between buggy or normal state depending on what you do. This internal state appears to be per document, not application.  (Clue?)

A. Triggers

Free Orbit is BUGGY after doing one of these:

1. Clicking the Home View icon on upper left of the View Cube
2. Switching Workspace
3. After opening a document (Initially buggy after opening)
4. After pop-ups, e.g. Starting a simulation, viewing Generative Design outcomes

B. Workarounds

Free Orbit is NORMAL after doing one of these:

1. Use the Constrained Orbit tool to orbit for any amount (myself and others on this forum live with the problem this way)
2. Choose a face on the View Cube (e.g. Top/Bottom/Left/Right/Front/Rear)
3. Choosing a Named View from the browser

To Reproduce and Workaround the Bug

Summing Up A & B above, it's possible to repeatedly trigger and workaround the bug:

1. Set Default Orbit Type to Free Orbit in Preferences
2. Open a document and do NOT manipulate the view in any way
3. Select the Free Orbit tool and drag to the right or left - BAD
4. Click a face on the View Cube
5. Select the Free Orbit tool and drag to the right or left - GOOD
6. Click the Home View icon
7. Select the Free Orbit tool and drag to the right or left - BAD
8. Select the Constrained Orbit tool and drag around
9. Select the Free Orbit tool and drag to the right or left - GOOD

Really really hope these can help lead closer to a fix. Love Fusion 360 but now that I use Simulation I’m having to use the workarounds repeatedly and it becomes very tiresome.

Thank you,

Eric

2.0.9930

Active Plan: Fusion 360, Subscription

macOS 10.16.0 (Actually I'm running 11.2.3)

https://forums.autodesk.com/t5/fusion-360-support/free-orbit-rotation-bug-with-bizarre-fix/m-p/9477005/highlight/true#M86671

https://forums.autodesk.com/t5/fusion-360-design-validate/orbit-bug/m-p/6601648/highlight/true#M75605

https://forums.autodesk.com/t5/fusion-360-support/orbit-bug/m-p/7935887/highlight/true#M24414

Posted as 3DConnexion problem but possibly the same issue

https://forums.autodesk.com/t5/fusion-360-support/3d-connexion-spacemouse-spin-also-rotates/m-p/9096200/highlight/true#M69349

https://forums.autodesk.com/t5/fusion-360-support/3dconnexion-spacemouse-horizon-lock-constrain-orbit-missing/m-p/9697278/highlight/true#M97643

[Anonymous]

That is interesting. They definitely have camera transform bug issues. The problem is constant with SpaceMouse though, and was so infuriating I returned my beloved SpaceMouse for a refund, so can no longer test this. They are probably using a Camera.Transform.PointAt() function without  an UP vector, or equally likely rotating the camera about 'SELF' space rather than 'WORLD' space after translating around the object. The fix is probably one line of code, and I just cannot understand the stunning level of apathy to fix this infuriating issue. I bludgeoned both companies into acknowledging the issue and generating a bug number both ends, and introduced the quality assurance managers of both companies via email months ago, but STILL no fix... I need to post a Sponge Bob 'Nobody Cares...' meme...

[EricY_Design]

It’s a pretty major feature and bug oversight for sure, considering it’s just basic navigation. What a bummer you had to return your SpaceMouse, just as I found a solution to locking rotation of a sketch plane. I’ll post it up on the other thread.

Well...thanks for all your efforts, it looks like now the developers are going to give it another look. Fingers crossed...

[DreBz]

Hi @EricY_Design ,

Thanks for bringing this bug back up to the surface in such a thorough manner !
It's good to know others are also having this same issue.
It has been driving me crazy for so long now... I really don't understand how such a serious usability/user experience bug has lived on for so long.

I hope someone from Fusion 360 reads your post...

Dre

[Phil.E]

Logged as a bug. Ref. FUS-80242*

@DreBz  Thanks for the video showing the issue.

*Disclaimer: logging the issue, providing a ticket number, or response to this post does not guarantee the issue will be solved. Until the issue is triaged, reproduced, ranked, and assigned to the team that works on UI issues, there is no way to know what is happening or what the fix might entail. So at this time there is no way to predict a future state of this issue.

[EricY_Design]

Thanks for logging this bug PhilE, really hoping it can get a high priority.

I just tried on Surface Pro touchscreen, it is affected too. So it looks to be common to all of Free Orbit - mouse, circle widget crosshairs, 3DConnexion, and touchscreen.

[EricY_Design]

Finally, I think I found a way to workaround the horizontal Free Orbit bug for good - by overriding the default Home view:

1. Pick a face on the View Cube, choose a Named View, or do a little bit of Contrained Orbit with a regular mouse. This gets horizontal Free Orbit working normally.
2. Adjust the view to desired, right-click on the House icon->Set Current View As Home, and choose between Fixed Distance or Fit to View
3. Save the document.

Now as long as you never do a Reset Home, Free Orbit will be normal for this document from now on.

Seems like the bug is tied to a “bad” view object in the code, set as Home by default on any new document, that either contains or triggers a wrong camera transform function. Hitting the House icon, switching workspaces, or answering pop-ups restores to Home view by design so would bring back the problem time after time. By starting off with a “good” view from View Cube or Named Views then assigning it as Home, Free Orbit will stay normal.

This not getting fixed in years is disappointing to say the least. I have now seen it on another Autodesk product too, so it may be part of a bigger shared library (Neutron?) outside of Fusion…which makes it all the more unacceptable frankly - view navigation is so fundamental to any 3D software!

Well, I hope this helps,

Eric

[Roost-Concepts]

Thanks for posting a solution, @EricY_Design. This issue is also happening to me. It’s one of the main reasons I’m still getting quotes for other CAD/CAM packages. The movement of the model is so unpredictable. @Phil.E Is there any update of a fix ETA? Thanks!

[Phil.E]

Not yet.

[mrares]

It's been another 2 years and the 3dConnexion mouse is unusable on macOS because of this...

[Phil.E]

Have you tried using Lock Horizon in the 3Dconnexion settings? It is intended to address this issue.

[mrares · Accepted solution]

Hello Phil,

I owe you deep gratitude because you've pointed me at what looks like a fix. The lock horizon function isn't really good (because it limits roll) but thanks to you I've finally figured out where the settings for this are and experimented with it, the winning setting (for me) is to change the Motionmodel to Target Camera. I've also enabled "Use Selected Item" though I don't think it has a huge effect