Transform animation from usdz files flickers

📚 Official Books Metal by Tutorials
1

So I’m successfully rendering an animation from blender in a USDZ file. However, about halfway into the frames the animation starts to jerk, like it’s rotating the sphere the wrong way, then it works again. Previewing the same usdz file in Reality Composer Pro or running it in a RealityView it runs fine… which makes me think there is some issue with the:

mesh.transform?.getCurrentTransform(at: currentTime)

in the sample code for chapter 24.

Anyone else has attempted to play back animation in a usdz files and seen this issue?

2

These are the frame transforms being applied when the flickers happen. What I don’t understand here is why this works fine when playing back the usdz file elsewhere. Seems like the rotation around y is going off here and not being interpreted correctly.

simd_float4x4([[0.6125287, -0.025369445, -0.60100394, 0.0], [0.42181203, -0.5934105, 0.45494953, 0.0], [-0.42886347, -0.61988777, -0.4109207, 0.0], [1.2950171e-08, 1.1179482, 1.2408344e-08, 1.0]])

simd_float4x4([[0.6151772, -0.036901627, -0.59769225, 0.0], [0.4184066, -0.5865311, 0.46685925, 0.0], [-0.42840812, -0.6258275, -0.40230212, 0.0], [9.589567e-23, 1.1179482, 6.845449e-17, 1.0]])

simd_float4x4([[-0.17963608, 0.3218674, 0.7753535, 0.0], [0.48135242, -0.6101316, 0.364801, 0.0], [0.6878018, 0.5110591, -0.05280073, 0.0], [-1.3404945e-09, 1.1179482, 4.546797e-09, 1.0]])
3

Are you able to share the usdz file?

I applied your transforms to the beachball and they seem to work ok.

Animation.zip (2.1 MB)

4

“I’m grateful for the effort you put into gathering and sharing this information. Brevard County Property Appraiser It’s truly valuable to me.”