Blackmagic Forum

Howdy Troops,

I need assistance with a task. I need to track some points on a rotational object. I have added a video to help show what I am trying to achieve. Please take a look and provide your advice, or questions.

I know there is timing involved for the flashes, this is my tweaking to get the flash objects aligned. I am struggling with the tracking, and at that point to insert the flash media, especially with this being a circular/rotational path, and the tubes will be going behind the sphere. The other item that I'm struggling with is getting the flash media aligned based on the rotational/orbital perspective. Most positions will be okay as a 2d perspective, however, as the tube faces a more direct in-line with the camera, the flash would have more width/girth than length/height. For this I guess I need to find a different flash shot.

Here is a link to view the video describing what I need help with.

https://www.dropbox.com/scl/fi/g7tbik5s ... keqcm&dl=0

Thank you.

AIRMAN DILLARD

If everything is fixed and the sphere rotates around its orbit in place, than perhaps it would be easier to build a sphere of the same size in 3D using one of the primitives in the Shape3D tool. Sphere obviously. and add tubes, which could be build using cylinder with low diameter and longer in lenght. You place them and match the virtual camera to your existing camera. Than you will have easy time putting the flashes on the end of tubes and animating flashes or whatever else you need. Its hard to say more without seeing the actual clip you are working with, but that might be easier than trying to track everything with obstacles, but than again, maybe its not, hard to say without seeing it.





You could than add locator 3D node to each of the points where you want lights to be. Locator 3D can convert 3D space coordinates to 2D so you can, use it to apply 2D effect like a flash or glowing light or something to position in 2d which is driven by 3D locator data. its pretty easy to use. For lens flare etc

This is the basic idea of how it works.


Fusion 6 - Locator


So I would try to re-create rough sphere with sticks coming out of it, use locator 3D to get what you would try to track but in reverse. And than you can use that data as if you tracked those points to apply your effect and hide the sphere and all that from view. Which you only need to get position data.

Thank you Kruno, good suggestion. I didn't add this, my fault, I was trying to keep the video short. Unfortunately, I cannot create this, the .gif file is a screen record of a company logo. It was created as a CAD model, the rotation was added to the sphere of the model and screen recorded. I will try your suggestions. Thank you

SNAFU RADIO 1943kHz wrote: Unfortunately, I cannot create this, the .gif file is a screen record of a company logo. It was created as a CAD model, the rotation was added to the sphere of the model and screen recorded. I will try your suggestions. Thank you

By the way another thing you could do if the object is always rotating around the same place is animate the trajectory manually from point A to B using motion path and than you can use depth map, or simple gradient to merge based on that so you can have something dissapear as its going around the sphere. It might be easier to build if you are not doing 3D.

Here is the basic idea and tutorial.

Can you Deep Compositing in Fusion and Resolve_

Thank you, I will try that as well.