Character Models Don't Render In ViewportFrames

Reproduction Steps

Not 100% sure the cause, seems intermittent in-game. I’ll have a ViewportFrame with 4 character models in it, and only 2 or less out of the 4 will render.

Here’s a file that features one of the character models in the viewportframe that doesn’t render. On my PC the bug will persist even when re-opening the file, or moving the viewportframe to a different place file.

BrokenViewportFrame.rbxl (244.3 KB)

Expected Behavior

I expect objects within a ViewportFrame’s focus to render normally.

Actual Behavior

Parts within the character model just don’t render. This seems to transcend places and UIs, I’ve included a roblox file that features a character model within ScreenGui.MVP.WorldModel which doesn’t render even after reopening the file.

You can tell it’s in view because you can duplicate one of it’s parts and move it outside of the character model to make it appear.


No, all of the parts within the viewportframe have perfect properties, there’s no way to detect from a code perspective that it’s not rendering.

Issue Area: Engine
Issue Type: Display
Impact: High
Frequency: Constantly
Date First Experienced: 2022-11-10 00:11:00 (-05:00)
Date Last Experienced: 2022-11-19 00:11:00 (-05:00)


As far as I am aware this seems to be some kind of new change to ViewportFrames having probably unintended side effects. It isn’t just character models that I can tell, stuff seemingly only re-renders when the camera’s CFrame changes. I’m also experiencing issues with stuff simply not rendering.


I could say I had noticed the issue days ago (until someone unearthed it as a bug, I considered it a technical mitigation). Whenever the camera is fixed into a certain CFrame, no object seems to reflect the workspace objects properly.

I have a model with a couple parts hinged or connected ropes, and I move some particular ones in order to comply with the project’s functionality. Every part moving was assigned a tag, and I have a code snippet that finds the parts with the same tags. Constraints work only inside the workspace, yet I update every part’s CFrame in accordance with its matching part on the viewport frame. Hence no need for constraints on UIs. It seems I need to set the CameraSubject to a part constantly acting; otherwise, the parts don’t render as how it does in the workspace.

You’re supposed to use a WorldModel instance inside the viewport frame if you want objects in viewports to behave like they do in workspace. That’s unrelated to the bug I posted about.

Forgot to mention that I’m already using a WorldModel to process the rendering. I don’t know what causes that to happen, but it doesn’t matter if I use it under WorldModel or outside it.

Ah I see what you mean, I misunderstood.

In other words, having the camera get updated frequently makes those parts render? I’ll have to try that on my end, could be a workaround for my issue. My parts don’t move but they don’t render at all even when perfectly still.

EDIT: Moving, editing, or changing the camera does nothing for my issue, things still refuse to render.

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Thanks for the report! We’ll follow up when we have an update for you.

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This bug is related to nested ViewportFrame. We’ll fix it in a future release.
For now, you can get rid of this issue by removing the nested ViewportFrame (the one under Gun/RET/Scope).

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