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Eri Levin
simple key issue
on Sep 18, 2016 at 11:21:29 pm

Hello, I am new to Fusion. Any ideas why this is happening? I've keyed a shot and merged with a background. But I am having a problem with boundaries and canvas in general. how do you properly make a shot transparent right now it only keys to the boundaries of the shot. Please see attached:





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Simon Ubsdell
Re: simple key issue
on Sep 20, 2016 at 12:19:22 pm

It's hard to tell from your description but it looks as though you are using a crop tool prior to your keyer.

Try putting it after the keyer instead and that should solve the problem, if I have understood it correctly.

Simon Ubsdell
tokyo productions
hawaiki


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Eri Levin
Re: simple key issue
on Sep 20, 2016 at 12:34:44 pm

Sorry. This may make more sense. I am not using a crop tool. But after the key I am using a transform to rotate, scale and position. This makes the background feel like it's cropped. I am certain it is probably something really simple but I can't find anything about it. I've been an adobe After Effects user for many moons and now trying to wrap my head around Fusion. Thanks Simon!



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Simon Ubsdell
Re: simple key issue
on Sep 20, 2016 at 1:42:25 pm

This is a peculiarity in the way the Ultra Keyer works - you'll notice that you don't have the same issue with Primatte.

Here's a workaround.

Instead of piping your Ultra Keyer output directly into the merge, use it to mask your foreground (green screen) image.

To do that add a Channel Booleans tool to your foreground image and then pipe the Ultra Keyer output into the foreground input of the Channel Booleans. Set the mode to Multiply and then set all the channels to take Alpha FG.

If you then take the output of the Channel Booleans and pipe that into your Merge, you will avoid the cropping issue.

There may be another way around it but that one works. You can use the Merge Size control to adjust the size of your foreground and can dispense with the Transform node. If you do keep the transform node, make sure that you use it to affect both the input to the Keyer and the input to the Channel Booleans for obvious reasons.

Hope that helps.

Simon Ubsdell
tokyo productions
hawaiki


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Simon Ubsdell
Re: simple key issue
on Sep 20, 2016 at 3:23:24 pm

Just in case that didn't make sense here's a screengrab that shows the Flow and the Channel Booleans channel assignments:



Simon Ubsdell
tokyo productions
hawaiki


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Eri Levin
Re: simple key issue
on Sep 21, 2016 at 7:36:29 pm

Hi Simon,

Thank you so much for your help. That worked. I used ultra keyer because it appears to give me cleaner results. Maybe I am using Primatte incorrectly.

Now I have ran into another problem. I have another shot that I was trying to also merge over that background without any luck. What is the proper way to merge several keyed shots into a background. If I use another merge, all kinds of strange things start to happen. Maybe I am misunderstanding nodes. Also how do you turn on a safe frame or viewer boundary. I am supposed to be in a 1080p project, but I am little confused how this boundaries are reflected in the monitors. Thank you so much.



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Simon Ubsdell
Re: simple key issue
on Sep 21, 2016 at 7:47:06 pm
Last Edited By Simon Ubsdell on Sep 21, 2016 at 7:47:49 pm

[Eri Levin] " I used ultra keyer because it appears to give me cleaner results. Maybe I am using Primatte incorrectly."

In principle, you should be able to get much better results with Primatte, but it's not terribly intuitive, I will admit.

[Eri Levin] " I have another shot that I was trying to also merge over that background without any luck. What is the proper way to merge several keyed shots into a background. If I use another merge, all kinds of strange things start to happen. "

What strange things are you seeing? I can't tell what's wrong from the screengrab of your Flow, which seems to have your second keyed image unconnected to the Merge ...

[Eri Levin] "Also how do you turn on a safe frame or viewer boundary. I am supposed to be in a 1080p project, but I am little confused how this boundaries are reflected in the monitors. Thank you so much."

In Fusion there's really no such thing as a project of a specific frame size. It depends on many things but mostly on what you are using as your "base layer", if that makes sense. I notice that your background is not actually 16:9, so the first thing I would recommend is that you composite (Merge) that over a Background node that is set to 1920x1080. At least then you will be compositing over a true 1080 background.

If you can post your Fusion composition (no need to add the media but it would help), I could advise more specifically.

Simon Ubsdell
tokyo productions
hawaiki


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Simon Ubsdell
Re: simple key issue
on Sep 21, 2016 at 8:03:39 pm

[Eri Levin] "Also how do you turn on a safe frame or viewer boundary."

Sorry, forgot to answer that. In any Viewer window, hit Command+G (on the Mac), or right-click and select Guides/Show Guides from the menu.

Simon Ubsdell
tokyo productions
hawaiki


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Eri Levin
Re: simple key issue
on Sep 22, 2016 at 1:29:00 pm

Hi Simon,

I can't thank you enough. Command + G did it. Also creating a background at 1920 x 1080 is a perfect solution to keep things at correct size. Thank you. Sorry for the vague "strange things" comment upon merging other green screen shots. I am attaching two screen shots of what I mean. Because all shots are flipped 90 degrees I am using a transform to flip and position correctly.

As you can see on the screen grabs there the shot on the previous merge scale down. To me if the transform is piped before the merge why is that having an impact? Thank you so much.




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Simon Ubsdell
Re: simple key issue
on Sep 22, 2016 at 1:45:08 pm
Last Edited By Simon Ubsdell on Sep 22, 2016 at 3:51:36 pm

[Eri Levin] "As you can see on the screen grabs there the shot on the previous merge scale down. To me if the transform is piped before the merge why is that having an impact?"

I'm not sure I understand what you've done there, sorry.

You don't really need to be using the Transform tool to do what you're doing - all those operations (flip, rotate, scale position, etc.) are available within the Merge tool. You might find it easier to work that way for now to avoid confusion.

If you'd like to email me [simon(at)tokyo-uk(dot)com] your Fusion composition or post it here, I could try and get to grips with what you're done and give you an explanation. From the screengrab of the flow itself I can't see what parameters you have set for either the Transform or the Merge ...

Edit: I would note that because you haven't composited your background image over a 1080 Background tool, it could be very large - I can't judge from what you've shown there. That would account for the size discrepancy you are seeing.

Simon Ubsdell
tokyo productions
hawaiki


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Simon Ubsdell
Re: simple key issue
on Sep 23, 2016 at 10:15:57 am

To clarify what I'm talking about here are three different examples, using a 1920x1080 foreground green screen clip (the blonde girl) and a background source image that is much larger, namely 4336x2896.

In this first example, the foreground is merged directly over the background, with the result that it looks very small.



In this next version I have composited the background over a Background node that is set to 1920x1080 - now the foreground looks the right scale, but we are only seeing a small portion of the background.



Finally, I have adjusted the Merge Size (of the node where the background image is composited over the 1080 Background node) so that it fits within that new frame size and we see (almost) all of the background image within our final composite.



Each of these strategies has its use but hopefully you can see from this the value of "formatting" your background image so that it matches your foreground in terms of the frame size.

Simon Ubsdell
tokyo productions
hawaiki


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