Tracking backwards fails after gap in track #86262

New Issue

Sebastian Koenig · 2021-03-04T08:46:51+01:00

Sebastian Koenig commented

2021-03-04 08:46:51 +01:00

System Information
Operating system: Linux-5.8.0-7642-generic-x86_64-with-glibc2.32 64 Bits
Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 460.39

Blender Version
Broken: version: 2.93.0 Alpha, branch: tracking_scopes, commit date: 2021-03-01 15:22, hash: 380a0b096a
Worked: (newest version of Blender that worked as expected)

Short description of error
I found this bug while testing the tracking_scopes branch, but the same error occurs in 2.91 as well.
So I tracked a marker forwards until the feature was blocked. (Let's call this section A). A few frames later, when the feature is visible again I continued to track forwards. (Section B)
Now I went back to the start of section B in order to track a few frames backwards to narrow the gap. However, the tracking fails, even though the feature is clearly visible and the search area is big enough.
However, when I do Clear Track Path Before, thereby deleting section A, it tracks backwards perfectly.
I tested this with the old Fabrik shot as well, and could reproduce it there.

Exact steps for others to reproduce the error
Open the attached file and load the Fabrik_Eingang.mov (@Sergey should have it). Also known as MVI_4005.mov from Track Match Blend 01. track_backwards.blend

Try to track backwards from frame 135. At least here that fails.
Now do Clear Track Path Before and try again. It should track just fine.

**System Information** Operating system: Linux-5.8.0-7642-generic-x86_64-with-glibc2.32 64 Bits Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 460.39 **Blender Version** Broken: version: 2.93.0 Alpha, branch: tracking_scopes, commit date: 2021-03-01 15:22, hash: `380a0b096a` Worked: (newest version of Blender that worked as expected) **Short description of error** I found this bug while testing the tracking_scopes branch, but the same error occurs in 2.91 as well. So I tracked a marker forwards until the feature was blocked. (Let's call this section A). A few frames later, when the feature is visible again I continued to track forwards. (Section B) Now I went back to the start of section B in order to track a few frames backwards to narrow the gap. However, the tracking fails, even though the feature is clearly visible and the search area is big enough. However, when I do Clear Track Path Before, thereby deleting section A, it tracks backwards perfectly. I tested this with the old Fabrik shot as well, and could reproduce it there. ![track_backwards.png](https://archive.blender.org/developer/F9865042/track_backwards.png) **Exact steps for others to reproduce the error** Open the attached file and load the Fabrik_Eingang.mov (@Sergey should have it). Also known as MVI_4005.mov from Track Match Blend 01. [track_backwards.blend](https://archive.blender.org/developer/F9865041/track_backwards.blend) Try to track backwards from frame 135. At least here that fails. Now do Clear Track Path Before and try again. It should track just fine.

Sebastian Koenig commented

2021-03-04 08:46:51 +01:00

Added subscribers: @Sergey, @sebastian_k

Falk David commented

2021-03-04 10:42:51 +01:00

Added subscriber: @filedescriptor

Falk David commented

2021-03-04 10:42:51 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Falk David commented

2021-03-04 10:42:51 +01:00

I can confirm this on the 2.92.0 release and the latest 2.93.0 Alpha, branch: master, commit date: 2021-03-04 06:43, hash: ef7efc3751.

I can confirm this on the 2.92.0 release and the latest 2.93.0 Alpha, branch: master, commit date: 2021-03-04 06:43, hash: `ef7efc3751`.

Sergey Sharybin self-assigned this 2021-03-08 09:56:06 +01:00

Sergey Sharybin commented

2021-03-08 09:56:06 +01:00

Wow, the Eldritch Bug! Love it!

From quick thought process and quick code investigation seems that its caused by tracking prediction always going forward.
Is surely not a recent regression, but is something super important to get fixed!

Wow, the Eldritch Bug! Love it! From quick thought process and quick code investigation seems that its caused by tracking prediction always going forward. Is surely not a recent regression, but is something super important to get fixed!

Falk David commented

2021-03-10 16:59:11 +01:00

Note: If this does get a fix, the commit should be added to #85958.

Steffen Dünner commented

2021-03-15 14:32:29 +01:00

Added subscriber: @SteffenD

blender-admin commented

2021-03-15 15:48:15 +01:00

This issue was referenced by blender/libmv@ad9546d231

This issue was referenced by blender/libmv@ad9546d2319b0db3e1ccc41c4f84899729d1ad1e

blender-admin commented

2021-03-15 15:48:15 +01:00

This issue was referenced by c82f65b096

This issue was referenced by c82f65b096b90d80ea50be40afa826e7368d87a2

Sergey Sharybin commented

2021-03-15 15:55:30 +01:00

Changed status from 'Confirmed' to: 'Resolved'

Sergey Sharybin closed this issue

2021-03-15 15:55:30 +01:00

Sergey Sharybin commented

2021-03-15 15:58:10 +01:00

@filedescriptor Hi. This is a really old bug (6 or 7 years) and it is not that trivial/safe. I do not really think we should rush it into a corrective release.

Falk David commented

2021-03-17 11:03:34 +01:00

Alright +1

Sign in to join this conversation.

No Label

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Tracking backwards fails after gap in track #86262