Canvas UI masks not working on iPad Air 2

Target Platforms Mobile
1

I’ve got a fairly simple setup to mask an image in UI:

  • Canvas

  • Mask (Canvas Renderer, Image (.png), Mask)

  • Image (Canvas Renderer, Image (.png))

In an empty project, with nothing else in a scene, this works properly on all devices, including our lowest-spec iPad Air 2. However, in our production project, this same setup does not work on iPad Air 2 – the image is completely visible, as if the mask was not even there. On all other devices the masking does work as expected.

Is there a reason why this particular setup wouldn’t work on-device in our project? The scene it’s in does contain a number of other UI canvases, but changing the sort order of this particular canvas to be before or after all other canvases doesn’t change the outcome.

Is there perhaps a hardware limitation we’re running into in-game, with many more objects in the scene and many more canvases being rendered? A depth/stencil buffer being an upper limit on the number of canvases or masked objects? A rendering order problem? This is the only device on which we’re having this problem (all of them support Metal).

UI Mask does not work on iPAD 4th generation and iOS simulator
2

Submit a bug report using Unity Bug Reporter, especially you already have a reproducible project.

3

Yeah, submitting a report presently. I noticed that a similar question has been posted before , with no resolution, but I’ll link it here in case I do receive an answer/solution.

4

Most of the time I use RectMask2D instead of Mask because it’s more efficient. Have you tried it instead?

1 Like
5

I’ve heard back from Unity and apparently this is a known issue. @_Daniel I’ll try your suggestion and reply back if I figure something out.

6

Oh, hm. I should specify that I’m using this image mask + image inside of a UI canvas. I’m having trouble getting a Sprite Mask + Sprite to work in the canvas – notably, just adding a Sprite Mask with right click → 2D Object → Sprite Mask creates the object, but it has a regular transform instead of a RectTransform when created. I don’t know if sprite masks will work in this context…