Flame Forum
Welcome to Autodesk’s Flame Family (Flame, Flare, Flame Assist, Lustre) Forums. Share your knowledge, ask questions, and explore popular Flame topics.
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Motion vector with ROI

9 REPLIES 9
SOLVED
Reply
Message 1 of 10
juhatak
854 Views, 9 Replies

Motion vector with ROI

Hi,

 

I was trying to test Motion vector with ROI turned ON to speed up caching process, but after caching the full range, for some reason my Gmask is sliding like crazy. I have set my reference frame and have done as told in many Motion vector tutorials EXCEPT I have turned on my ROI and have set ROI area inside F8 view.

 

Is there some special trick to make it work with ROI?

 

 

Thanks,

Juha

 

In cases where you know that the tracking is to be performed in a very localized area of a scene, you can use the ROI contraint to minimize the area to analyse.

To analyse only an area of a scene:

  1. Double-click the Motion Vectors map to display its menu.
  2. Display in the Motion Vectors menu, display the Analysis tab.
  3. Enable ROI.
  4. Press F8 to display the Motion Vectors map in Object View.
  5. In Object View, resize the area to frame the area to track.
  6. Close Object View when complete.
9 REPLIES 9
Message 2 of 10
Grant.Kay
in reply to: juhatak

hi Juha,

 

From my understanding, when you use the ROI to limit an image, you are effectively cropping the source being analysed.  This means that the Motion Vector analysis will be different because it is not taking into account all movement in the image.   

 

Unfortunately there is no magic button to make it all work.  Sometimes it works well and other times the ROI will cause issues with Motion vectors and motion warp tracking.   You need to choose the option that gives you the best results.  It may not be the ROI in this case.

 

Please hit the Accept as Solution button if my post fully solves your issue or answers your question.

 

Regards

Grant

 


Grant Kay
Principal Learning Content Developer

---------------------------------------------------------------------------------
The Official Autodesk Flame Learning Channel
http://www.youtube.com/flamehowtos

The Official Autodesk Smoke Learning Channel
http://www.youtube.com/smokehowtos

Also available as podcasts on iTunes

Follow me on twitter @discreetuk for the latest training updates.
---------------------------------------------------------------------------------
Message 3 of 10
juhatak
in reply to: Grant.Kay

Hi Grant,

 

Would you mind sharing some workarounds to speedup motion vector caching?  Caching 3k isn’t that fast as you can imagine. 

 

Is there some clever ways to scale down ROI section of the footage and do the trick and then put back over original footage with fixed patch?

 

 

cheers!

Message 4 of 10
Grant.Kay
in reply to: juhatak

Hi Juhatak,

 

There aren't any "clever" ways to speed up the initial motion vector analysis and integration.   Even by cropping the frame with the region of interest, the results will be different because less movement in being analysed.   I completely understand the frustration but its the nature of the technology.

 

However, once you have done your analysis and integration, there are a few ways to keep the cache and even bake all the information into a UV map, which should make things really fast once the initial calculations are done.

 

I go through this in great detail in two videos on the Flame Learning Channel.

 

 

 

Please hit the Accept as Solution button if my post fully solves your issue or answers your question.

 

Regards

Grant

 

 

 

 


Grant Kay
Principal Learning Content Developer

---------------------------------------------------------------------------------
The Official Autodesk Flame Learning Channel
http://www.youtube.com/flamehowtos

The Official Autodesk Smoke Learning Channel
http://www.youtube.com/smokehowtos

Also available as podcasts on iTunes

Follow me on twitter @discreetuk for the latest training updates.
---------------------------------------------------------------------------------
Message 5 of 10
juhatak
in reply to: Grant.Kay

Hi Grant,

 

I was wondering since there is ROI option, there must be some kind of ‘not too difficult’ way of making use of it. Now after your comment it seems to be kind of useless. What about if I need only portion of motion vector data like talents face not going right to another extreme opposite in composition? In that case I wouldn’t need full frame motion vector, right?

 

Also it seems Foundry Nuke have added GPU support for generating motion vector data to get way faster response. Do you have any plan to do something similar?

 

Anyway, I’m really liking the way Flare is easing my tedious beauty work with motion vector combined to A2Beuty matchbox by the way. It is totally awesome. 

 

 

Best,

Juha

Message 6 of 10
Grant.Kay
in reply to: juhatak

Hi Juha,

 

Unfortunately Motion Vector technology is not bullet proof and there are so many instances that can make it succeed as well as fail.    The ROI may in some cases create the right result and in other cases, similar to your experience, will not work.   Without working with your media and investigating the issue, I cannot give a more concise answer.

 

However one thing that did work for me which may help you, is I had a case where other motion vectors were not necessary for my track and they also landed up causing my motion vectors to slide the track.   So before doing the analysis, I did a rough roto of my object and comped that over black.  When i did the analysis, it created the movement of just the area I wanted.  I don't think there was a performance improvement but I did see an improvement in the accuracy of the track.  Just a suggestion.

 

I cant comment on plans for future releases of Flame but I certainly encourage you to log this as a feature request on the Flame Feedback Portal so that the dev team read about your request.   Go to https://feedback.autodesk.com/welcome/ and submit your information.

 

We're happy to hear that Flame is helping with the work you do and we'll continue to work to make it even better.

 

Please hit the Accept as Solution button if my post fully solves your issue or answers your question.

 

Regards

Grant

 

 

 


Grant Kay
Principal Learning Content Developer

---------------------------------------------------------------------------------
The Official Autodesk Flame Learning Channel
http://www.youtube.com/flamehowtos

The Official Autodesk Smoke Learning Channel
http://www.youtube.com/smokehowtos

Also available as podcasts on iTunes

Follow me on twitter @discreetuk for the latest training updates.
---------------------------------------------------------------------------------
Message 7 of 10
juhatak
in reply to: Grant.Kay

Well, at leas for my own purpose I have found good speedup workflow.

 

1. Create Action and read in original to BG and media 1.

2. Add Resize node between original and media1.

3. Adjust cropping area to fit where have to perform beauty work.

4. Adjust media1 axis location to mach BG using difference blending mode.

5. Generate Motion vector using cropped media1. (instead of generating original size (in my case 3200x1800) motion vector sequence, cropped area should be way faster)

6. Do your beauty work and that's it.

 

At least this method should works just fine as long as talent isn't moving too much inside screen. Or even if talent would move across full frame width, you could crop height if possible to crop down resolution.

 

 

Best,

Juha

Message 8 of 10
joelosis
in reply to: juhatak

Message 9 of 10
juhatak
in reply to: joelosis

Thanks Joel as always. ROI indeed needs some sort of update for next release.

Message 10 of 10
sztom998
in reply to: joelosis

Thanks, It's working. Maybe it's the current expedient method.

I am waiting for the Flame to give a new method. If it will just to analysis a gmask area I want instead of the entire picture. It's useful for a 4K, 6K, 8K media.

Can't find what you're looking for? Ask the community or share your knowledge.

Post to forums  

Technology Administrators


Autodesk Design & Make Report