Roto node constantly gives me pass through

Hello, I’m new to Natron, I’ve been finding it a very good alternative to After Effects for most of my needs.

However, I’m having trouble, as recently, whenever I plop down a Roto or RotoPaint tool and connect it to whatever I need to rotoscope, a P appears in the corner of the node, saying

“This node is a pass-through and produces the same result as <Whatever node it’s connected to>”

I apologize if this is a silly question, but is there some way to fix this issue? Any suggestions would be appreciated.

The roto node is empty, if you place a rotoshape the indicator it will disappear.
On the left side no changes on output, on the right side the mask copied into the alpha channel.

Hi Levente_Vass,
it seems to me like it’s a smart optimization trick.
If nothing is drawn within the Roto node, then it’s like an empty node.
So it’s being disabled, to speed up the render :slight_smile:

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Ehh, roto mask input doesn’t working.

Oh, that’s a different problem.
On which OS are you running Natron, and what version ?
I’m on Windows 10 running Natron v2.3.14, and i don’t have this kind of issue.

I use the 2.3.14 under gentoo linux. Is this a platform specific problem? It’s a serious bug.

Specific bugs occur depending on which OS you are using.
And for Linux based OS, which distro.
You can open a ticket on github and describe the bug.
Or i can do it for you.

Okay I understand.

I think the problem is that I’m trying to rotoscope avi’s with an alpha channel, and it’s not letting me, any suggestions you have that can help?

Ok, I create a ticket.

Try remove alpha channel with Remove node or export the avi to sequence without alpha, use exr or tiff format. Don’t use avi mov and other vid format under compositing process, use image sequence. Sometimes I use mov shots, eg. smoke, fire, rain, but this is just an element, sometimes easier to use.

Alright, I removed the alpha channel, and it works fine now. Thank you very much.

It’s a shame you can’t roto transparent objects, but oh well. Maybe they can try to implement that later.

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