Motion Tracking with Image Sequences

Wondering how to accomplish a certain animation task? Ask here.

Moderators: Fahim, Distinct Sun, Víctor Paredes, erey, Belgarath, slowtiger

Post Reply
User avatar
Dakacha
Posts: 5
Joined: Tue Apr 21, 2020 4:23 am
Location: Michigan
Contact:

Motion Tracking with Image Sequences

Post by Dakacha » Sun May 24, 2020 11:36 pm

Good evening,

I'm new to Moho and I'm finding new features almost every day (my version is Pro 13 as of typing this). After importing an image sequence from Blender, I clicked on the image sequence layer and discovered the Video Tracking tool. I successfully tracked the image sequence, only to discover that the "Animation > Track Layer To Video" option is greyed out and unselectable. I haven't found much literature online describing how Motion Tracking in Moho works; this video by the Smith Micro Graphics YouTube channel is the most in-depth tutorial I've seen on the subject. It seems like, although Moho lets me track an image sequence, it doesn't let me actually use the tracking data for anything.

Can you use motion tracking with image sequences? If not, why does Moho let me do motion tracking if I can't use the tracking data?

Thank you.
User avatar
Greenlaw
Posts: 4661
Joined: Mon Jun 19, 2006 5:45 pm
Location: Los Angeles
Contact:

Re: Motion Tracking with Image Sequences

Post by Greenlaw » Mon May 25, 2020 12:26 am

After tracking your footage, you need to select the layer you wish to follow the tracking data by using Animation>Track To Video. A window will pop up that lets you select the tracked layer. If you have multiple tracking points, the layer can use it for rotation and, I'm assuming, scale. It's been a while since I tried tracking in Moho but I think that's pretty much it.

Ok, I just tried it in Moho 13 and it does work, with video or image sequence. The workflow is not completely intuitive but once you step through the process, it's actually pretty simple.

Hope this helps.
D.R. Greenlaw
Artist/Partner - Little Green Dog | Little Green Dog Channel on Vimeo | Greenlaw's Demo Reel 2019 Edtion
Lead Digital Animator, Dreamworks Animation

Image
User avatar
Greenlaw
Posts: 4661
Joined: Mon Jun 19, 2006 5:45 pm
Location: Los Angeles
Contact:

Re: Motion Tracking with Image Sequences

Post by Greenlaw » Mon May 25, 2020 12:38 am

Just a thought: I haven't tried this but try linking a group layer to the tracked layer. This way you can easily offset whatever is inside the group to make corrections or additive animation.
D.R. Greenlaw
Artist/Partner - Little Green Dog | Little Green Dog Channel on Vimeo | Greenlaw's Demo Reel 2019 Edtion
Lead Digital Animator, Dreamworks Animation

Image
User avatar
Dakacha
Posts: 5
Joined: Tue Apr 21, 2020 4:23 am
Location: Michigan
Contact:

Re: Motion Tracking with Image Sequences

Post by Dakacha » Mon May 25, 2020 5:29 am

Greenlaw wrote:
Mon May 25, 2020 12:26 am
After tracking your footage, you need to select the layer you wish to follow the tracking data by using Animation>Track To Video. A window will pop up that lets you select the tracked layer. If you have multiple tracking points, the layer can use it for rotation and, I'm assuming, scale. It's been a while since I tried tracking in Moho but I think that's pretty much it.

Ok, I just tried it in Moho 13 and it does work, with video or image sequence. The workflow is not completely intuitive but once you step through the process, it's actually pretty simple.

Hope this helps.
I've tried systematically selecting every different layer on different frames but the option for "Animation > Track Layer To Video" simply is not available on any of them. I tried making a new file with a different image sequence to no avail. When I tried a movie clip (mp4) it did work, which tells me it's the file type, but it's defeating the purposes of using an image sequence if I must convert them to video files. The image sequences are PNG files with alpha transparency, if that makes any difference. If I had to use JPG files that would also defeat the advantages of using PNG (the advantage being the alpha channel transparency).
Greenlaw wrote:
Mon May 25, 2020 12:38 am
Just a thought: I haven't tried this but try linking a group layer to the tracked layer. This way you can easily offset whatever is inside the group to make corrections or additive animation.
You can link group layers to the tracked layers? If you mean going to "Animation > Track Layer To Video" with the group layer selected, I tried that too. This is driving me crazy.
User avatar
slowtiger
Posts: 5492
Joined: Thu Feb 16, 2006 6:53 pm
Location: Berlin, Germany
Contact:

Re: Motion Tracking with Image Sequences

Post by slowtiger » Mon May 25, 2020 9:32 am

You could always render the image sequence into a video from Moho and re-import, then tracking should work in any case.
AS 9.5 MacPro Quadcore 3GHz 16GB RAM OS 10.6.8 Quicktime 7.6.6
AS 11 MacPro 12core 3GHz 32GB RAM OS 10.11 Quicktime 10.7.3
User avatar
Greenlaw
Posts: 4661
Joined: Mon Jun 19, 2006 5:45 pm
Location: Los Angeles
Contact:

Re: Motion Tracking with Image Sequences

Post by Greenlaw » Tue May 26, 2020 8:04 pm

Dakacha wrote:
Mon May 25, 2020 5:29 am
I've tried systematically selecting every different layer on different frames but the option for "Animation > Track Layer To Video" simply is not available on any of them...

...You can link group layers to the tracked layers? If you mean going to "Animation > Track Layer To Video" with the group layer selected, I tried that too. This is driving me crazy.
I took a quick look at my test scene and then tried to recreate it to see if I did anything you might be missing. One possiblity: I noticed the Track Layer to Video command didn't become active until I clicked the Set Last Frame button. Maybe that's it?

This was in Moho 12.5. I'll check 13 later today when I can take a break. If that doesn't work for you, let me know and I'll check that here again.

Re: Group. I checked that this morning too and, yes, I was able to attach a group layer to a tracked layer using the Track Layer To video command. BTW, this is how I found out about clicking the button before the command became active in the menu. I tried this in only in 12.5 this morning. Will verify if this also works in 13 later.

Another observation: Tracking is a little flakey when clicking the Play button. It seems to work more reliably when I step through the timeline frame-by-frame. This is with either frames or video. Surprisingly, this seems to work a little better with my video clip than the image sequence of the video, but this probably depends on the codec and image format used.

(This behavior seems familiar and it's probably why I never think of Moho for video tracking. It sort of works but there are better/easier ways to do this with many compositing programs. I like to use After Effects and the free Mocha AE tracker that comes with it. Fusion works pretty good too but when I'm working with 2D cartoon renders from Moho, I'm usually working in AE for compositing and fx.)
D.R. Greenlaw
Artist/Partner - Little Green Dog | Little Green Dog Channel on Vimeo | Greenlaw's Demo Reel 2019 Edtion
Lead Digital Animator, Dreamworks Animation

Image
User avatar
Dakacha
Posts: 5
Joined: Tue Apr 21, 2020 4:23 am
Location: Michigan
Contact:

Re: Motion Tracking with Image Sequences

Post by Dakacha » Tue May 26, 2020 8:31 pm

slowtiger wrote:
Mon May 25, 2020 9:32 am
You could always render the image sequence into a video from Moho and re-import, then tracking should work in any case.
I suppose what I could also do is import two versions of the tracked layer, one in a video format and one in an image sequence. Then I could get the tracking data from the video, apply it to the desired layer, and then hide the video version so only the image sequence version remains. A roundabout way of doing it, but I may not have a choice. Another reason I'm adverse to using video is for some reason it really bogs the performance of Moho down for me. For some reason image sequences have far less impact on performance for me.
Greenlaw wrote:
Tue May 26, 2020 8:04 pm
I took a quick look at my test scene and then tried to recreate it to see if I did anything you might be missing. One possiblity: I noticed the Track Layer to Video command didn't become active until I clicked the Set Last Frame button. Maybe that's it?

This was in Moho 12.5. I'll check 13 later today when I can take a break. If that doesn't work for you, let me know and I'll check that here again.

Re: Group. I checked that this morning too and, yes, I was able to attach a group layer to a tracked layer using the Track Layer To video command. BTW, this is how I found out about clicking the button before the command became active in the menu. I tried this in only in 12.5 this morning. Will verify if this also works in 13 later.

Another observation: Tracking is a little flakey when clicking the Play button. It seems to work more reliably when I step through the timeline frame-by-frame. This is with either frames or video. Surprisingly, this seems to work a little better with my video clip than the image sequence of the video, but this probably depends on the codec and image format used.

(This behavior seems familiar and it's probably why I never think of Moho for video tracking. It sort of works but there are better/easier ways to do this with many compositing programs. I like to use After Effects and the free Mocha AE tracker that comes with it. Fusion works pretty good too but when I'm working with 2D cartoon renders from Moho, I'm usually working in AE for compositing and fx.)
I agree it's flakey when using the play button. I have experience with Mocha and 3D point image tracking in compositing software (such as After Effects and HitFilm) and I agree it's easier and more reliable, but it would be nice to be able to do some motion tracking within Moho. Thank you for checking, I look forward to seeing what you find out when you test it in version 13!
User avatar
Greenlaw
Posts: 4661
Joined: Mon Jun 19, 2006 5:45 pm
Location: Los Angeles
Contact:

Re: Motion Tracking with Image Sequences

Post by Greenlaw » Wed May 27, 2020 1:03 am

Dakacha wrote:
Tue May 26, 2020 8:31 pm
Another reason I'm adverse to using video is for some reason it really bogs the performance of Moho down for me. For some reason image sequences have far less impact on performance for me.
This makes complete sense. When using a video, the entire clip needs to decompress and load in RAM. if the cip is lengthy, it can bog down an animation program that's already doing some heavy animation processing. This is why I prefer using image sequences...this way, the computer only loads a single frame at a time when rendering, which requires a lot less RAM and improves stability. The trade off might be interactivity depending on size of the files and how fast your network is. I like to use JPEG in Moho for reference image sequences like animatics because they stream well even on a modest network, and I use PNG in Moho for final quality when rendering.
I agree it's flakey when using the play button. I have experience with Mocha and 3D point image tracking in compositing software (such as After Effects and HitFilm) and I agree it's easier and more reliable, but it would be nice to be able to do some motion tracking within Moho. Thank you for checking, I look forward to seeing what you find out when you test it in version 13!
Sure, glad to help. I'll post again if I learn anything new.
D.R. Greenlaw
Artist/Partner - Little Green Dog | Little Green Dog Channel on Vimeo | Greenlaw's Demo Reel 2019 Edtion
Lead Digital Animator, Dreamworks Animation

Image
Post Reply