This document describes the process for preparing a watch 3D model with functional dial hands, enabling it to display the current time in WANNA Virtual Try-On (VTO) and 3D Viewer. 

The technology uses a single animation track combining the movements of all hands. The animation runs at 1 FPS, with each second represented by a separate frame. For a 12-hour dial, the animation therefore requires 43,200 frames.

The Blender add-on described in this guide supports Blender 3.3 LTS, 3.6 LTS, and 4.2 LTS only. 

Restrictions

• Only dial hands animation is supported at present in VTO. For additional animations that can be used in 3D Viewer see 3D Viewer Model Requirements.
• Texture animation is not supported.
• The animation increases the model size by approximately 2 MB, which may slightly affect download time.

Recommended Workflow

Follow this workflow when preparing an animated watch model:

• Create the 3D model in your preferred modelling software.
• Texture the model in Adobe Substance 3D Painter using the WANNA Shader.
• Export the textured model into Blender.
• Generate the animation using the provided script (see instructions below):
  • Install the script if not already installed.
  • Prepare the model for the script: group and rename nodes, and align the model according to watch requirements.
  • Run the animation script.
• Position the watch on the wrist (see Watch Positioning Guide).
• Export the final model as glTF/glb.

Script Installation

• Download the Watch Animation Add-on (right click → Save Link As).
• In Blender, go to: Edit → Preferences → Add-ons → Install.
• Select the file you downloaded and install it.
• Enable the add-on by ticking the checkbox.

Creating the Animation

1. Place the watch dial horizontally on the Z=0 plane.
2. Set the hands pivot at X=0, Y=0 with the Z axis as the rotation axis. The hands should initially point to 12 o’clock.

3. Create dedicated top-level nodes for each dial hand. Each should point to 12 o’clock. Use the following naming convention:
   • hour_hand → hour hand
   • minute_hand → minute hand
   • second_hand → second hand

4. Create a separate node for the watch crystal and name it glass.
5. In the add-on, click the Analog 12 Hours button. This will generate animations for all three hands.
6. Without closing Blender, position the watch on the wrist (see Watch Positioning Guide).
7. Click Export to generate the glTF/glb file. This ensures the animation is exported correctly for use in the WANNA SDK.

Example Reference

A reference watch model is available, demonstrating the correct structure and preparation prior to running the script.

WANNA_watch_animation_example.glb

Known Issues

• If the model includes an ambient occlusion texture or baked shadows, ensure these are baked without the dial hands present. Otherwise, unwanted artefacts may remain in the texture.
• Occasionally, the animation exports at 24 FPS, resulting in very fast hand movement. To fix this, manually set the animation to 1 FPS in Blender.

Script Changelog

• v1.92 → added support for Blender 4.0
• v1.91 → added support for Blender 3.6 LTS