From 9fb7235d93ef530e725e0c571e4645e2ba852d73 Mon Sep 17 00:00:00 2001
From: crosstyan <crosstyan@outlook.com>
Date: Tue, 25 Mar 2025 10:17:08 +0800
Subject: [PATCH] Refactor preProcessExtrinsic function to handle both Matrix4
 and array inputs for extrinsic parameters. Add error handling for invalid
 inputs and update transformation sequence for camera-to-world conversion.

---
 src/App.tsx | 36 +++++++++++++++++++++++-------------
 1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/src/App.tsx b/src/App.tsx
index e4974fa..74903a4 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -119,12 +119,14 @@ const Scene = () => {
     let Rt: THREE.Matrix4
     if (extrinsic instanceof THREE.Matrix4) {
       Rt = extrinsic
-    } else {
+    } else if (Array.isArray(extrinsic)) {
+      console.assert(extrinsic.length === 16, "extrinsic must be a 4x4 matrix")
       Rt = new THREE.Matrix4()
       // @ts-expect-error 16 elements
       Rt.set(...extrinsic)
+    } else {
+      throw new Error("extrinsic must be a 4x4 matrix or an array of 16 elements")
     }
-    console.assert(Rt.elements.length === 16, "extrinsic must be a 4x4 matrix")
     const font = new FontLoader().parse(HelvetikerRegular)
     const camera = new THREE.PerspectiveCamera(fov ?? 60, aspect ?? 4 / 3, near ?? DEFAULT_NEAR, far ?? DEFAULT_FAR)
     const helper = <cameraHelper args={[camera]} />
@@ -161,17 +163,25 @@ const Scene = () => {
     )
   }
 
-  const preProcessExtrinsic = (extrinsic: number[]) => {
-    // Create the initial world-to-camera transform
-    const worldToCamera = new THREE.Matrix4()
-    // @ts-expect-error 16 elements
-    worldToCamera.set(...extrinsic)
+  const preProcessExtrinsic = (extrinsic: number[] | THREE.Matrix4) => {
+    let Rt: THREE.Matrix4
+    if (extrinsic instanceof THREE.Matrix4) {
+      Rt = extrinsic
+    } else if (Array.isArray(extrinsic)) {
+      console.assert(extrinsic.length === 16, "extrinsic must be a 4x4 matrix")
+      Rt = new THREE.Matrix4()
+      // @ts-expect-error 16 elements
+      Rt.set(...extrinsic)
+    } else {
+      throw new Error("extrinsic must be a 4x4 matrix or an array of 16 elements")
+    }
 
-    // Convert from Z-up to Y-up first (this affects world coordinates)
-    const worldZupToYup = Z_UP_TO_Y_UP.clone()
 
     // Then handle OpenCV to OpenGL camera convention
-    const cameraConversion = CV_TO_GL_MAT.clone()
+    const cameraCvt = CV_TO_GL_MAT.clone()
+
+    // Convert from Z-up to Y-up first (this affects world coordinates)
+    const worldCvt = Z_UP_TO_Y_UP.clone()
 
     // Final transformation:
     // 1. Convert world from Z-up to Y-up
@@ -179,9 +189,9 @@ const Scene = () => {
     // 3. Convert camera coordinates from OpenCV to OpenGL
     const final = new THREE.Matrix4()
     final
-      .multiply(cameraConversion)
-      .multiply(worldToCamera)
-      .multiply(worldZupToYup)
+      .multiply(cameraCvt)
+      .multiply(Rt)
+      .multiply(worldCvt)
 
     // Invert to get the camera-to-world transform
     final.invert()