Motion Tracking position helpers (locators)

My idea comes up as I miss so much a feature from the good old Boujou tracking software named Locators.

Actually, in Blender, when you try to reconstruct a scene geometry from the motion tracking module you can get Empties on every tracked point and even a point cloud with selected tracked points. Those are really good to figure out how to model or place the scene geometric elements, but, all of that info are coming from already tracked points only. And here comes the idea I suggest.

After you have a succesfull track would be lovelly to add a point in the image clip and get where it is in the 3D scene without the need to solve the whole scene again.

I know that I can actually add some tracking points manually where I need more info but there is two cons with this:

• Sometimes you can't get a good track on those exact points so you have to delete it.
• Sometimes you get a good tracked point where you want but for any reason after you add it and resolve gain the solving isn't as good as before so you need to delete or deactivate it to get a better solve and loosing that bit of positional info.

That's why this is a task to do when you already have a good Solve...

Boujou did it this way: After a good solving the user adds a locator by hand (two different frames of the sequence where needed). As Boujou already had the Solve done it calculates the relative position of the selected point based on (I asume) a reprojection method. That way you didn't need neither to track those points neither to solve again but you end up with a locator (empty) on the exact place you need it in the 3D scene.

Hope it makes sense and it's explained well enough.

Cheers! Ignasi aka Topeich.