Unity XR Single Pass Instanced rendering and UI

user_17417673 0
Viewed 302

I was wondering if anyone has recommendations regarding the use of the Unity Canvas-based UI system (UGUI) along with the Single Pass Instanced rendering mode for XR applications (?)

My concerns are whether the UI elements will render as Single Pass Instanced or if they are actually just rendered twice - potentially causing performance issues.

As far as I can see on the default UI shader (Unity 2019.4.21 built in shaders for the built in render pipeline), it doesn't appear to support GPU Instancing (correct me if I am wrong). I can of course create my own shader with support for GPU Instancing in accordance with the guidelines here but I don't know if the UI rendering system will actually respect that (?) thinking that there might be a reason why is not implemented in the default UI shader...

And if the UI rendering does indeed not support GPU Instancing, does it then have some other optimized way of rendering that makes up for the lack of GPU Instancing?

I am sorry for these slightly fuzzy questions. I am just trying to figure out which path to take with my project - whether to go the UI (UGUI) way or not.

Best regards, Jakob

mrtk unity3d augmented-reality rendering user-interface
1 Answers

I try to migrate a big VR project on Unity2021 and Single Pass Instanced.

I have no issue with UGUI. I had some issue with some of ours shaders and third parties shaders and in that case, the issue was the rendering was visible only on one eye or it was different some way between the two eyes.

It did not check the draw call specificaly on UGUI but for me if it's the same on both eye it's rendered once.

I have both screenspace and wordspace GUI.

Alex

user_29649610
Related