Mixing and object in scene render pass and delay frame

I’m doing a Polaroid-type effect where you can tap the screen and it freezes like it’s taking a photograph.
I’m building it with shader render passes and a delay frame patch.
I also have a face-tracker on, I’m trying to also add a sparkle on the side of the mouth when it freezes.
what’s the best way to solve that?


In order to add the sparkle in the frozen frame, ideally you’d have the camera feed and the sparkle on the same render pass layer, and freeze that.

If you don’t want the sparkle visible before the freeze, you can tie the same trigger you’re using for freezing the screen (let’s say Screen Tap by default) and use it to toggle the visibility of the sparkle just before you freeze the frame. You could untoggle it’s visibility after in a variety of ways (after a certain delay, after another Screen Tap, and so on…)

Hopefully I understood the question :stuck_out_tongue:

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Thanks for answering and yes you understood the question perfectly. what I’m not sure about is how to add the sparkle to the same render pass layer.

the image above shows my current set-up for the delay frame. I’m currently also passing the frozen texture through a colorLUT.

To add the sparkle on a render pass layer, I think you can simply add a “Scene Render Pass” in between your Mix and Shader Render Pass patches. Then take your sparkle object from the hierarchy and either add a tag for it that you copy in the Render Pass or you can directly drag it into the patch editor and connect that in the inputs of the newly added patch.

There’s sometimes some weird things to do like making the Scene Render Pass go through a Shader Render Pass to connect it to the rest of the chain but you should already indirectly be doing it since you already have a shader render pass in.

Hope this works, sorry for the approximative answers, I haven’t delved into render passes in a hot second ^^


I’ve been able to figure it out, placing the “scene render pass” between the mix and shader render pass patches almost works for me but the position of the sparkle is determined by the faceTracker so it won’t be frozen by the delay frame.
but after a lot of tweaking, I got it to work.

see the patch setup above.
Thank you again🫡


Awesome, congrats on getting it to work! :smiley:

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