diff --git a/ArchitectureColoredPainting/BvhTree.cpp b/ArchitectureColoredPainting/BvhTree.cpp
index 13ad178..e537e29 100644
--- a/ArchitectureColoredPainting/BvhTree.cpp
+++ b/ArchitectureColoredPainting/BvhTree.cpp
@@ -46,10 +46,8 @@ bvhPtr BvhTree::subBvhTree(QVector4D initBound[], int l, int r) {
 
 void BvhTree::traverseBvhTree(bvhPtr now, std::vector<GLuint>& children, std::vector<QVector4D>& bounds) {
 	if (now == NULL) return ;
-	if(now.get()->getSon(0) || now.get()->getSon(1)) {
-		children.push_back(now.get()->getSon(0));
-		children.push_back(now.get()->getSon(1));
-	}
+	children.push_back(now.get()->getLeftSon(0));
+	children.push_back(now.get()->getRightSon(1));
 	bounds.push_back(now.get()->bound);
 	traverseBvhTree(now.get()->child[0], children, bounds);
 	traverseBvhTree(now.get()->child[1], children, bounds);
diff --git a/ArchitectureColoredPainting/BvhTree.h b/ArchitectureColoredPainting/BvhTree.h
index 1ccc0c6..0292602 100644
--- a/ArchitectureColoredPainting/BvhTree.h
+++ b/ArchitectureColoredPainting/BvhTree.h
@@ -22,11 +22,17 @@ struct BvhNode {
 	static bool y_compare(QVector4D a, QVector4D b) {
 		return a.y() < b.y();
 	}
-	GLuint getSon(int k) {
-		if (k >= 2) return 0;
-		if (child[k] == NULL) 
+	GLuint getLeftSon(int k) {
+		if (child[0] == NULL) {
+			return INT_MAX;
+		}
+		return child[0].get()->lab;
+	}
+	GLuint getRightSon(int k) {
+		if (child[1] == NULL) {
 			return 0;
-		return child[k].get()->lab;
+		}
+		return child[1].get()->lab;
 	}
 	BvhNode() {
 		child[0] = child[1] = NULL;
@@ -55,6 +61,7 @@ public:
 	void traverseBvhTree(bvhPtr now, std::vector<GLuint>& children, std::vector<QVector4D>& bounds);
 	// 获得 Bvh （rootBvh部分）的 children 数组，包围盒数组 vector 传输
 	void getBvhArray(std::vector<GLuint>& children, std::vector<QVector4D>& bounds);
+	// 获得 BvhTree 中节点总数
 	GLuint getBvhNodeNum();
 };