When to use Insert or Remove?

I’ve been trying to establish best practices for different situations and have been getting a little confused on when it’s best to use Insert with Clean plate vs Remove with Clean plate. Both involve tracking a background and masking the object to be removed. In my situation I’m trying to remove/replace wrinkles on a sheet in the background of a moving shot. Any insight or opinion by Mary or others would be greatly appreciated. : ) Thanks

It is a good question.

Think of Mocha Pro’s Insert Module like a standard composite. It has basic compositing, track offsets and the mesh warper. If you wanted to use multiple painted patches in the insert module, you would need to edit.dissolve between them prior in the chain before importing into Insert.

Mocha Pro’s Remove Module is a bit different in that it can analyze the background track and try to find the clean frames in a shot. For example when there is camera movement and there is distance between the FG and BG, often portions of the clean frames exist in the shot. Remove Module can use these frames and then apply “illumination” to try and match the color, lighting shifts, etc.

The Remove Module also has the clean plate import function that allows the user to generate clean plates to be created externally. A key concept here is that the Remove Module can interpolate between the external clean plates and the internal (ones found in clip time) OR use Clean Plates exclusively which will only look at the external frames. We find this pretty unique for difficult removes.

For the shot you describe it is tough to say. It sounds like you need to paint at least one clean frame. If you require Mesh Warping, you use the Insert Module. If the patch has a lot of lighting shifts, using Remove w/illumination might be more effective.

Hope this helps. We are looking to improve the workflow for these types of removes in a future version!

1 Like

Thank you for answering this Ross. Very helpful.

I’d like to add the further distinction that if there’s simple, nice planar data behind the object, it’s a good candidate for remove. However, highly animated, organic, shifting, and multiplanar backgrounds are not good candidates for removes.

If anything moves over the top of the object you have to patch over, the insert is the best candidate. So if you have a person in the FG and focus blur is softening their edges, this is a time to use the insert instead of the remove because you’ll have to rebuild the BG and rebuild the edges of the FG object to feather over the top.

Hope that helps further!

Cheers,
Mary

One quick follow up question. Seems like the best times to use Insert are Screen replacement, sign replacement and occasionally “cheating” with a clean plate on a blemish removal or something similarly simple. Otherwise the Remove module seems like the right option. Do you find this to be true? Are there any other common uses for the Insert with Cleanplate that you find using often? Thank you.

I use the insert for matte paintings, patching, logo replacements, anytime something is moving over the area I need to replace, beauty work, body reshaping, anything I need to auto calculate motion blur for, and other things like that.

This is fantastic clarification and definitely helpful. Thank you Mary.

Wow, thank you for writing up this list. I was actually just watching a Remove Webinar from March 2015 (these are great learning tools) and there is a scene with a girl in a mirror and you are removing the camera guy’s hand. I don’t expect you to remember doing this, but the scene had many of the characteristics you mention in your comment above for when Remove is not a good candidate. Multi planar, shifting, blurry background. Could you have used a Clean Plate Insert for this shot?

The answer there is there’s a difference between being an ideal candidate and getting away with it. None of these are hard, fast rules, it all depends on the shot.

However, blurry BGs the remove tool doesn’t care about. Blurry FGs it does. For the mirror shot, the parralax shift in the mirror isn’t enough to throw Mocha off. I just make sure to track it separate from the mirror frame. Essentially the reflection is a plane, so it works.

Do you see what I mean?

Yes I do. These are extremely helpful answers. I appreciate you taking the time to respond. Like I said earlier, I’m just trying to establish general ideas of when to use which tool and I feel like you’ve given me those with your responses. : )

Of course. Honestly, I need to sit down and make a tutorial on what to use when but it would be really long. I probably need to redo an old tutorial I made on “how mocha thinks.”