Understand the ways you can optimize your URP project for XR devices.
This page describes the optimization techniques for universal render pipeline (URP) projects that target untethered extended reality (XR) devices. An untethered XR device is an XR device that aren’t connected to a desktop with a wire.
Most untethered XR devices use tile-based GPUs. The guidelines on this page help you use this hardware architecture more efficiently and avoid using rendering techniques that are less efficient on those devices. To learn more about how tiled-based GPUs work, refer to the additional resources section.
To optimize your XR project, consider the following:
The following sections describe these methods in more detail.
Vulkan API is more stable and provides better performance compared to OpenGL ES API in URP projects targeting XR platforms. Many new OpenXR features are only available on Vulkan.
Refer to Configure graphics APIs for information on how to change the graphics API to Vulkan.
Use the OpenXR Plugin in projects that target XR platforms.
Enable the following settings in your OpenXR project:
Tip: Consider whether URP Application SpaceWarp is appropriate for your project. Application SpaceWarp can improve frame rate significantly, but might cause visible artifacts for some content.
In Unity 6.0 and newer, new URP projects use the render graph system. Refer to Benefits of the render graph system to understand the benefits of render graph.
Consider the following when choosing between Forward and Deferred rendering for untethered XR devices.
You can change the Rendering Path in the Rendering section of the Universal Renderer Asset.
On Unity versions earlier than 6.7, Forward or Forward+ rendering is the more efficient render path.
Multi-sample Anti-aliasing (MSAA) is only supported with Forward and Forward+ rendering. If your project relies on MSAA, use Forward or Forward+ rendering. In Unity 6.0 and newer, Forward+ supports XR and removes the light-count limit of Forward. Use Forward+ if your project uses MSAA and many dynamic lights.
In URP, Deferred rendering generates several render targets for the G-buffer. On tile-based GPUs, accessing those render targets can require multiple graphics memory loads (Qualcomm documentation), which is slow.
In Unity 6.7 and newer, URP adds on-tile support to the Deferred rendering path. This keeps the G-buffer and lighting pass on-tile as a single render pass, which reduces memory bandwidth overhead.
Deferred rendering has no limit on the number of lights that affect an opaque GameObject, which benefits scenes with many dynamic lights.
Note: Deferred rendering doesn’t support MSAA. To use MSAA, choose the Forward or Forward+ rendering path.
Refer to Deferred and Deferred+ rendering paths in URP for more information.
On XR devices, Unity recommends that you use on-tile post-processing. Post-processing techniques without on-tile post-processing enabled are expensive on untethered XR devices because post-processing adds intermediate textures.
In Unity 6.3 and newer, you can use on-tile post-processing to enable certain URP post-processing effects on XR devices. Refer to On-tile post-processing to learn more about on-tile post-processing and how to enable it in your XR project.
In versions of Unity older than Unity 6.3, Unity recommends that you disable post-processing techniques because on-tile post-processing isn’t available.
Avoid using geometry shaders on platforms with tile-based GPUs. Some devices don’t support geometry shaders.
The generation of additional primitives and vertices breaks the tiled GPU flow because the division of primitives after the binning pass becomes invalid.
Tile-based GPUs can store more samples in the same tile. This makes Multi-sample Anti-aliasing (MSAA) efficient on mobile and untethered XR platforms. 2X MSAA value provides a good balance between visual quality and performance.
You can change the MSAA settings in the Quality section of the URP asset. For more information on MSAA, refer to Anti-aliasing in URP.
Note: MSAA is only supported with Forward and Forward+ rendering.
Note: MSAA breaks on-tile rendering. If you enable Tile-Only Mode or on-tile post-processing, disable MSAA.
Disable depth priming on XR platforms. XR devices have two views, which increases the performance impact from performing the depth pre-pass.
For untethered XR devices there are no benefits of performing the depth priming. You can obtain similar results using hardware optimization features, such as Low-Resolution-Z (LRZ) or Hidden Surface Removal (HSR).
For information on how to configure or disable depth priming, refer to the Depth Priming Mode property description.
Disable the Opaque Texture and Depth Texture properties to improve performance. Enabling those options causes extra texture copy operations, which requires extra GMEM loads.
Refer to Rendering for more information on these opaque and depth texture properties..
To identify if your current configuration is using intermediate textures, use the Render Graph Viewer window.
Screen Space Ambient Occlusion (SSAO) might have poor performance on mobile and untethered XR devices.
SSAO in URP requires the depth priming pass, two blur passes to reduce the noise, and an additional blit pass to clean the image. Such passes require several GMEM loads which have a high performance impact on tile-based GPUs.
Refer to SSAO for more information.
High Definition Rendering (HDR) has higher precision and improves graphics fidelity, but requires more bits per pixel to process. Disable HDR to reduce memory bandwidth and improve performance.
Most untethered XR devices don’t support HDR rendering.
To disable HDR:
Note: some features, such as HDR light estimation require HDR. Check the requirements for the features your project uses to ensure HDR isn’t required.
Unity recommends that you implement resolution scaling to reduce GPU workload and maintain a stable frame rate.
To learn more, refer to Resolution control in XR projects.
When you enable the Meta Quest build profile, Unity enables some automatic shader optimizations to reduce GPU frame time. You can also configure additional shader optimizations in your project. To learn more, refer to Configure shader optimizations for Meta Quest.
In Unity 6.6 and newer, the Adaptive Performance module supports OpenXR devices.
Enable the Adaptive Performance Basic provider in your OpenXR project to automatically adjust application quality based on device frame timing. Adaptive Performance helps maintain smoother performance and a more consistent user experience on XR devices.