SourceCode/Code2026/AecRxBase/GiDrawUtility.cpp

@@ -178,12 +178,20 @@ AECDLLIMPEXP AcGeMatrix3d GiDrawUtility::RotateAndMove(const AcGeVector3d &vtOri
 {
 	AcGeVector3d _vtOrig(vtOrig);
 	AcGeVector3d _vtDist(vtDist);
-	_vtOrig *= 1;// 保证长度不为0
-	_vtDist *= 1;// 保证长度不为0
-	AcGeMatrix3d mat(AcGeMatrix3d::kIdentity);
-	//mat = _vtDist.rotateTo(_vtOrig);
-	mat = _vtOrig.rotateTo(_vtDist);
-	mat.setTranslation(ptDist - ptOrig);
+	// 零向量没有方向，rotateTo 结果未定义，回退到 Z 轴
+	if (_vtOrig.isZeroLength())
+		_vtOrig = AcGeVector3d::kZAxis;
+	if (_vtDist.isZeroLength())
+		_vtDist = AcGeVector3d::kZAxis;
+
+	AcGeMatrix3d mat(_vtOrig.rotateTo(_vtDist));
+
+	// 矩阵语义为 p' = R·p + t。要把 ptOrig 搬到 ptDist，平移量必须是
+	// ptDist - R·ptOrig；用 ptDist - ptOrig 只在 ptOrig 为原点时成立
+	AcGePoint3d ptRotated(ptOrig);
+	ptRotated.transformBy(mat);
+	mat.setTranslation(ptDist - ptRotated);
+
 	return mat;
 }