Twinmotion VR: Troubleshooting

Please refer to the following checklist if you are experiencing trouble with Twinmotion in VR.

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Twinmotion Optimisation

For slow Twinmotion experiences, you will need to optimise your scene; there are visual settings to change but there are also optimisations in your model to make.

Please refer to this article by Twinmotion on optimising your scene:

https://dev.epicgames.com/community/learning/knowledge-base/rMyK/optimizing-your-twinmotion-scenes

Export Files

Consider using Twinmotion/Unreal Engine's DATASMITH files. Plugin install required. Or you may use standard file types like motionbuilder (.fbx).

Direct Link

Direct Link is not recommended for slow files, but you do have the option of Linking multiple files directly where Datasmith is supported. You need to have the file open during the Twinmotion's Import step and it will be available in the Direct Link menu. You are able to import multiple Direct Link files which gives you the option to assemble in pieces, and then finally collapse everything at the end.

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Object Hierarchy

• Object groupings in Twinmotion are decided upon import; it is recommended to collapse files as much as possible (refer above article)

  • Group objects by material and they will be imported as one object when Collapsed by Material during import

  • To keep ALL objects separate (not recommended), import while Keeping Hierarchy

    • Alternatively, you may export as many individual or grouped geometries as you wish if you want to control each object's material separately.

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Model Optimisation

• Simplify the mesh as much as possible

  • E.g. In Rhino; use the Mesh command to manually mesh objects + edit them to be as simple as possible

• What do you really see - if you are looking at something from far away, does it need to be full 3D or could it be a single plane?

• Import objects in a more efficient way (refer to the above article);

  • In general, one single object is preferred to smaller objects, e.g. a context model should be all booleaned together into a single mesh.

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Scene Optimisation

When setting up expansive or large scenes, take note of the following:

Hierarchy

Import and process the most important details first at their highest possible level of detail, e.g. your main building model before adding context. Breaking up files into sections will also help you to slowly import and troubleshoot.

Instancing (Refer above article)

Where you have duplicates of the same exact model, consider instancing it instead. Import a single copy of the mesh and duplicate it from the Scene Graph, you will have the option to paste it as an instance. This is a more efficient technique for large scenes. This may mean you do more composition from within Twinmotion.

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Connections, Accounts & Headset

Accounts and software

• Ensure Meta quest link is installed.https://www.meta.com/en-gb/help/quest/articles/headsets-and-accessories/oculus-rift-s/install-app-for-link/

• Unlock the headsets using the NExT Lab passcode. Come see us if you've forgotten what it is!

• Ensure you've made and logged into all relevant accounts.

• Meta account: log into your profile on the headset and Meta quest link software.

• Ensure Twinmotion is downloaded properly. TM account does not need to match with Meta.

Connecting laptop to headset

• Insufficient battery may cause issues.

• Ensure USB C cable is 3.2 (the cables that are provided with the headset kits).

• When connecting headsets to laptop via Meta Quest, run a test of the USB cable to ensure it is sufficient.

• On the headset > ensure quest link is turned on in the settings.

• ‘Use air link’ turned off; it's not compatible with university WiFi.

• Try resetting the headset and/or restart your laptop if issues persist.

Connecting Twinmotion to VR

• Meta Quest link and Twinmotion are required to be open for the process to succeed.

• On your laptop navigate to: Meta quest link > settings > general > OpenXR settings > ensure Meta quest link is set as the active OpenXR runtime

• In the same tab, ensure the 'allow unknown sources' toggle is on.

• Ensure divers are updated and restart Twinmotion.

• Open both Twinmotion and Meta Quest link as admin and try again if issues continue.

Slow Program

• Refer to the model Twinmotion Troubleshooting above; making changes to your scene is the most optimal way to increase performance.

• In general; Twinmotion VR can quickly become slow, so only populate areas that are in viewable within your VR experience.

• In scene properties; reduce scene detail.

• Navigate to: twinmotion > stats (bottom left of screen) > quality setup (top left) > ensure all options are set to 'low' in both the VR and desktop tabs

• Navigate to: twinmotion > stats (bottom left of screen) > quality setup (top left) > settings tab > refer to adjustments in next steps

• Probes resolution > reduce to 64 in viewport (you don't need to change the export level)

• Sky dome resolution > low (for viewport)

• Grass fading > near (this will reduce quality of ground plane but allow the model to run smoother)

• Save > autosave every 30 - 60 mins

• Do not use sync/autosync to link Twinmotion and Rhino. Datasmith save is preferred.

• As a last resort, delete your asset files for smoother running:locate twinmotion cloud library and delete folder. locate quixel cloud library and delete folder

Casting

• Use this link (https://www.oculus.com/casting/) and log-in with the same account on both headset and webpage.

• Start casting via the camera app on the headset.

• Double-check account logins if not successful.

Screenshots and screen recording

• Take screenshots while casting onto another screen for best results.

• Refer to this link with steps on how to screenshot within the headset: https://app.gitbook.com/o/-LXaaOYEZu7jgoWF-DHK/s/-LXautSvCbUco5Lv7YrH/virtual-reality/guides/twinmotion-vr-viewing/twinmotion-vr-features

• Low remote battery may cause issues. Navigate to settings and check battery.