Render Masks: Possible to hold the buffer of last render in RT?

[GidPDX]

Just wondering how we can get render masks to work with RT so that the previous render is held in frame while the mask portion updates. It seems to only be working the the standard Vray render, which isn't quite as useful as I'd had hoped.

What settings to I need to check to get it to work with RT?

[vladimir.nedev]

It's not possible at the moment. It's disabled because the edges get incorrectly blended with the previous image.

We might fix and re-enable it in the future, but I think it's disabled in V-Ray for Max/Maya as well at the moment.

The other problem is that the buffer needs to be reset if you move the camera or any other object.
Basically only material or light changes should keep the same buffer, as otherwise you get a solitaire like effect.

Greetings,
Vladimir Nedev

[GidPDX]

How bad are the edges? I think for some relighting and what not, I could tolerate some bad blended edges to be honest. I probably wouldn't use render masks for final rendering, but more for pre-comp look dev etc.

It makes sense that the buffer would need to update if there were an changes to to camera angle- wasn't expecting that.

I'd love to see what the bad edges look like...maybe a nightly build could have the buffer re-enabled? Is there a way on the user side through command line to enable it?

[vladimir.nedev]

I'd love to see what the bad edges look like...maybe a nightly build could have the buffer re-enabled? Is there a way on the user side through command line to enable it?

There isn't an option for this currently.
I can add one. I will log an issue about it and report back when it's in the nightly builds.

Greetings,
Vladimir Nedev

[GidPDX]

That would be great Vladimir. Even if the edges are a little rough and have some of the last render in them, I think for some of us this would still be a useful option to have.

[vladimir.nedev]

I've added the option in the 2017.04.27 nightly build.

Here is a short clip demonstrating it:

https://youtu.be/Ha3BwGShJ5o

The option in the UI:



Greetings,
Vladimir Nedev

[GidPDX]

Thanks Vladimir!

[Muhammed_Hamed]

Thanks Vladimir! Cannot wait to try it out!