Measuring Azure Spatial Anchors differences between Unity versions

Question

Hi,

I would greatly appreciate a perspective on the pros/cons of using different versions of Azure Spatial Anchors in my HoloLens 2 Mixed Reality application. (from Microsoft if possible)

I'm working on a HL2 application that is currently running on Unity 2019.4.33f1 and Legacy Built-in XR. According to the docs, this version of Unity + legacy XR supports up to ASA version 2.8.1.

Meanwhile, ASA versions 2.9.0 and up require Unity 2020+ as well as Unity's XR Plug-in framework.

Previously, we didn't upgrade beyond 2019.4.33f1 because a Unity version update broke some important features of our app, and it would require a larger refactor to make them compatible, or we would have to deprecate some of those features. We do want to upgrade eventually to keep up with the latest Unity features, but this has not been a high priority for these reasons.

However, recently we are looking to upgrade our anchoring system to ASA - the main reason for this upgrade is that we want to prioritize spatial anchoring accuracy and make sure content in our app appears in the correct world positions as consistently as possible. From our research, ASA seems to be pretty good at this!

So I was wondering if there were any significant differences in Azure Spatial Anchors performance/anchor location accuracy between 2.8.1 and 2.9.0 and up.

Since we are very heavily prioritizing anchoring accuracy and reliability, if it's worthwhile to upgrade to a newer Unity version to use the latest versions of ASA, we would strongly consider doing it. However, this might be a large scale undertaking, and if there aren't too many performance differences beyond compatibility with the latest versions of Unity/XR frameworks, it would save us quite a bit of time to not have to upgrade Unity.

I appreciate any advice/experiences on this topic!

Answer 1

Hello Benjamin,

There has been an improvement in accuracy in ASA SDK 2.10.0 - This release of Azure Spatial Anchors SDK includes a change that improves the accuracy of spatial anchors by leveraging the state of device's native tracking system in a better way. While locating existing anchors created with older SDK versions will improve, the most improvement comes when new anchors are created and located with this new SDK version.

That being said, I cannot tell you how significant it is for your use case and it's ultimately something that you can best determine after running some tests. However, the recommended Unity version is 2020.3 LTS, especially since 2019 is going to run out of support soon. Additionally, we are not recommending Unity 2019 due to Azure Spatial Anchors incompatibilities with AR Foundation 2. It is also worth pointing out that there was a timespan of 15 months between ASA SDK version 2.8.1 and the current latest version, 2.13.0, and there were a lot of bug fixes (see release notes) which are not backported. In that sense, we're always improving our products and generally suggest using the latest versions.