use camera's intrinsics and extrinsics params, convert image coordinates to camera 3D coordinates: float u = imagePoint.x; float v = imagePoint.y; simd_float3 cameraPoint; cameraPoint.x = (u - intrinsics.columns[2].x) * depth / intrinsics.columns[0].x; cameraPoint.y = (v - intrinsics.columns[2].y) * depth / intrinsics.columns[1].y; cameraPoint.z = depth; as this post say : the extrinsics do not define the transformation from the device anchor to the camera, but from the camera to the device anchor. (Actually extrinsics is a constant value!) so then transform 3D camera point to point in device anchor coordinates: simd_float4 cameraPoint4D = simd_make_float4(cameraPoint.x, cameraPoint.y, cameraPoint.z, 1.0); simd_float4x4 extrinsicsInverse = simd_inverse(extrinsics); simd_float4 world_point = simd_mul(extrinsicsInverse, cameraPoint4D); then use device anchor to transform to world position: simd_float4 world_point = simd_mul(weakSelf.deviceTransform, simd_make_float4(spacePoint.x, spacePoint.y, spacePoint.z, 1.0)); seem everything correct, but don't work, i don't know why, please help