Picture in picture using fusion mask

Hello,

I'm trying to make a clip that has picture in picture in a way where I apply a fusion mask on the top video clip so that it has blurry borders. In fusion page I'm applying ellipse mask on the target video and now I have encountered two totally different issues and one of them is a showstopper:

1) First issue is that when I select "mediaIn" node and press "ellipse" mask more often than not nothing happens. Meaning ellpise node is created and tied nicely to the mediaIn mask entry point but the mask does not do anything. On the other hand sometimes it does exactly what I expect it to do: I can shape the ellipse and blur out the border for a very nice effect and it plays perfectly on timeline playback.

2) Second issue is that after I have gotten the fusion mask working as I wanted to and I go to Delivery page and try to render my whole project then so far always 100% render job will not start and gets stuck at the step where it tries to calculate time needed until end of rendering. I have tried this on two totally different computers (macbook pro and a PC) and it gets stuck exactly on the same place.

During step 2 DaVinci Resolve gets so stuck that I have to force quit the program. Sometimes after force quiting DaVinci my project loses links to source material and I have to manually relink files.

I am using DaVinci Resolve 16.2. I have tried this on a 2019 macbook pro and on an older windows 10 PC. In both cases Davinci behaves the same. Am I doing something wrong?

My first thought is insufficient GPU for the task at hand.

What model card?

Do fusion clips require mandatory dedicated GPU? I was not aware of this. I'm using 2019 13" macbook pro with integrated intel gpu.
After some more testing I figured out that basically I cant use any kind of custom Fusion clip or Composite clip in my projects. They will play fine within the timeline playback but the project will not render in the delivery page.
After I removed all my custom fusion shenanigans and used default out of the box fusion titles and such then my project suddenly was able to render properly.

This does not seem like intended though. Like I said I also tried it on my gaming PC with an older but rather powerful dedicated video card and DaVinci Resolve behaved the same way: I could not use any of my own fusion clips.

Could anyone here who has a similar macbook pro like mine please try some simple custom fusion masking and then try to render? Will it work?

PS! If it was not obvious I am using the free version of DaVinci Resolve.

Thanks in advance.

What card was in the gaming PC?

Alright, I found a solution or workaround for my problem.

For anyone else running into the same issue how I got it fixed on my computer (2019 13" macbook pro). Honestly I'm not 100% sure which of the specific configuration options fixed the actual problem for me but what I changed are the following:
1) In DaVinci Resolve preferences -> In User tab I made sure that "Stop playback when a dropped frame is detected" and "Stop renders when a frame or clip cannot be processed" are UNCHECKED.
2) In "Playback" menu check "Use optimized media if available"
3) In "Playback -> Render Cache" check "User"
4) In "Playback -> Fusion Memory Cache" check "On"
5) Make sure in "Edit" page that all your Fusion Clips have been rendered (the blue line instead red line)
6) Optionally also create optimzed media for your project in "Edit" page
7) In "Delivery" page use "Custom" profile and in there in Advanced Settings make sure that "Use optimized media" and "Use render cached images" are CHECKED

I'm making an educated guess that the render cache related options are the ones that did it or me but now I can render successfully my projects that utilize any kind of fusion clips without problems.

I think I love you. This solved the problem for me. Thank you!

Thank you for this!