Projectors with Motion Vectors

Hey hive mind! First time caller, long time listener and Flame user.

I have a question that one of you might be able to help me with. I am experimenting with projecting images into waves for a music video using motion vectors. I want to know if there is a way to use a single over-sized still say 9k, to project onto the motion vector pass in a HD source, that doesn’t crop/tear the image based on the one reference point. The only way I can think of making it work is using multiple actions with varying set reference tracking points in the motion vector clip and masking it all in. Wondering, hoping there may be an easier way…

Any suggestions welcome!

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Hey Eugene,
First of all, the video looks staggering! Maybe I couldn’t understand what you’re trying to achieve, but you should be able to add reference points. You are using motion warp tracker in action right?

Thanks Sinan, just a quick test but has merit. Pretty difficult to describe but yeah MV in Action. For this test I am projecting a galaxy into the wave (MV Source) like someone is surfing in it.

Adding multiple reference points snaps the stills projection back to it’s original position each new point, so it’s not continuous. I can’t get the MV’s to use the oversized image, it only uses the crop of the default action resolution so as the water rises up it shows the original image at the bottom of frame, when there is much more in the still. I use MV’s all the time for fabrics etc but usually it is with an alpha. When trying to use the entire frame it tears the edges. Adding reference points doesn’t work.

Am I explaining this more clearly or making it worse :upside_down_face:

I understand a bit better, I think. I guess your problem is created by the extent of the MV pass which is generated by your original video. Maybe you could try to render the MV pass out of your action with overscan and then try to extend the edges downstream and use that as an MV pass?

Over Scan Settings

Use the over scan settings to render Action outputs in a larger canvas, without changing the active resolution (allowing you to easily fix a number of edge rendering issues, including AO, GMask Smoothing, Blooming, etc.).


I have tested that workflow previously but will give it another go. May have to find source footage that is larger than I require then crop in to mask the tearing. I did consider pixel spreading the edges out, creating an overscan as you suggest the cropping in the final framing.

Thanks for your suggestions! I’ll post my results if they prove out.

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Wow this looks so cool!


super cool test!

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What if you pan across the still before it’s projected, so outside the action? Use a 2d transform set to HD res and do the pan there (or another action node).

Thanks Chiroptera, good suggestion but that will create a motion contrary to the wave movement, the still will slide and not appear locked to the wave MV. Cheers!

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Ah…yeah, you’re right!

Could you reverse the clip, track the galaxy onto the reversed waves, then reverse the render and use that as a patch for the lower part of the frame where the tearing is occurring?


I think this is worth a shot, some creative problem solving there! Nice thinking @leowoo!

A great option for patch work Leo. Cheers!

What if you attached a big plate through a diffuse layer to a smaller surface which was attached to mv?