Thanks for following up, and apologies for the delay-- this slipped past me. Here’s a repro asset I wrote that you can test directly: https://github.com/alexchuber/Assets/raw/refs/heads/main/Repros/triangleNegScale.usdz For additional reference, here's the USDA content of the asset (material omitted for clarity): #usda 1.0 ( defaultPrim = "Root" metersPerUnit = 1 upAxis = "Y" ) def Xform "Root" { def Mesh "Triangle" { matrix4d xformOp:transform = ( (-1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (0, 0, 0, 1) ) uniform token[] xformOpOrder = ["xformOp:transform"] int[] faceVertexCounts = [3] int[] faceVertexIndices = [0, 1, 2] normal3f[] normals = [(0, 0, 1), (0, 0, 1), (0, 0, 1)] ( interpolation = "vertex" ) point3f[] points = [(0, 0, 0), (1, 0, 0), (0, 1, 0)] uniform token subdivisionScheme = "none" } } The steps to reproduce are just: Add the asset to a new Reality Composer Pro scene. Open the same asset in QuickLook on iOS/macOS. Compare the facing direction in both views. You should see that the triangles appear to have opposite front faces. Could this be an unsupported case, or something I’ve missed? Just wanted to double-check before filing feedback. Appreciate any insight!

Edited the original post, as I mislabelled the orientations :) This stuff is easy to mix up!