# Frequently Asked Questions

If you haven't found the answer to your question in the list, feel free to contact us via [Discord](https://discord.com/invite/Nep56Efu7A) or any other communication channel.

**Q: Can I use it with HTrace** [**SSGI**](https://assetstore.unity.com/packages/tools/level-design/htrace-screen-space-global-illumination-bundle-336930) **/** [**WSGI**](https://assetstore.unity.com/packages/tools/level-design/htrace-world-space-global-illumination-300382) **assets ?**\
\&#xNAN;*A: Yes. These assets are fully compatible and work well with each other. If you're experiencing issues with importing them to the same project, check* [*this section*](/htrace-ao/known-issues.md)*.*

**Q: How is it different from the original (V1) HTrace AO asset ?**\
\&#xNAN;*A: The new HTrace AO V2 asset is a major update and a complete rewrite with many improvements and new features. A short list of the most important changes can be found in the* [*Asset Store changelog*](https://assetstore.unity.com/packages/vfx/shaders/fullscreen-camera-effects/htrace-ambient-occlusion-v2-urp-369882#releases)*.*

**Q: Can I use it with the original (V1) HTrace AO asset ?**\
\&#xNAN;*A: No, installing both the new and old AO assets in the same project may lead to errors. The V2 version is an upgrade and is not meant to be used alongside V1.*

**Q: Does it support Forward / Forward+ / Deferred / Deferred+ rendering path ?** \
\&#xNAN;*A: Yes. All of these rendering paths are supported and produce near-identical visual results in terms of ambient occlusion in both pipelines. The only major difference is that* [*Exclude Casting*](/htrace-ao/settings-and-properties/gtao-settings/gtao-visuals.md#exclude-casting-unity-6000) */* [*Receiving*](/htrace-ao/settings-and-properties/shared-settings/visuals.md#exclude-receiving-unity-6000) *masking options in URP (for all AO Modes) work only in Deferred / Deferred+.*

**Q: Does it work with GPU Resident Drawer ?** \
\&#xNAN;*A: Yes.* 

**Q: Does it work with the new Mesh LOD system?** \
\&#xNAN;*A: Yes.* 

**Q: Can I use custom shaders with this asset ?**\
\&#xNAN;*A: Yes, if they are Shader Graph shaders. Custom hand-written shaders will also work, as long as they output valid Depth, Normals, and Motion Vectors data, if necessary, via the respective shader passes.*

**Q: Do I need an RTX GPU to use it ?**\
\&#xNAN;*A: RTAO mode requires compatible hardware and API, refer to this* [*section*](/htrace-ao/overview.md#other-differences-and-requirements) *for more information. GTAO and SSAO modes do not require special hardware.*

**Q: Is it fast ?**\
\&#xNAN;*A: HTrace Ambient Occlusion provides many performance* [*controls*](/htrace-ao/settings-and-properties.md) *that allow vast scalability, ranging from maximum performance to maximum visual fidelity. It's not possible to provide exact numbers as they depend heavily on hardware, scene complexity and frame resolution.*

**Q: Does it work on mobile devices ?**\
\&#xNAN;*A: It's untested.*

**Q: Does it work with VR ?**\
\&#xNAN;*A: Single pass VR is supported for HDRP. However, URP does not support VR at the current moment.*

**Q: Does it work with Apple devices (Metal) ?**\
\&#xNAN;*A: GTAO and SSAO modes work on Metal API. RTAO mode doesn't as Unity* [*doesn't support ray-tracing on Metal*](https://portal.productboard.com/unity/1-unity-platform-rendering-visual-effects/c/2220-hdrp-raytracing-effects-on-metal)*.*


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