RBDシミュレーションをVATでエクスポートしようとしているのですが、
lowポリのシミュレーションをTransformPieceSOPでハイポリの破片と置き換えると、
画像のようにVAT化した時に初期位置がズレてしまいます。
TransformPieceSOP自体の問題なのか、何かセットアップが間違っているのか、
それともエクスポートのエラーなのか、原因が掴めず困っているのですが、
こちら何が原因か分かりますでしょうか？

サンプルのhipを添付しました。
Houdini 19.0.455
UE5.0

Hey, Ken sent me this question. Hopefully google can translate my reply to something understandable.

The issue was the high res mesh contained zero-area degenerate primitives, which often happens after the initial fracture. While this does not cause visible issues inside Houdini, when imported into Unreal, the degenerate primitives are not recognized, which may have caused the mesh's vertex index to shift, therefore the UV channels to go crazy, and the overall mesh to look glitched out.

In this case, these bad primitives cannot be caught by Clean SOP or Unreal's Remove Degenerate mesh import checkbox. What you can do to fix it is shown here:



Unpack it (make sure unpacked version has @name). Triangulate (Avoid Small Angles on). Use Clean SOP to remove degenerates. Use Measure SOP to measure @area per piece by @name. Then blast primitives with tiny areas. Verify with Geometry Spreadsheet that you no longer have primitives with tiny areas. Pack it back by @name.

Result is in a video attached below. The edited HIP is also attached.

Thank you for your polite reply and sample data!
It worked like magic! thank you!