diff --git a/tests/RHI/OpenGL/integration/sphere/Res/Shader/sphere.vert b/tests/RHI/OpenGL/integration/sphere/Res/Shader/sphere.vert
index d368e057..72260d3e 100644
--- a/tests/RHI/OpenGL/integration/sphere/Res/Shader/sphere.vert
+++ b/tests/RHI/OpenGL/integration/sphere/Res/Shader/sphere.vert
@@ -11,7 +11,8 @@ uniform mat4 gProjectionMatrix;
 
 void main() {
     vec4 positionWS = gModelMatrix * aPosition;
+    positionWS.x = -positionWS.x;
     vec4 positionVS = gViewMatrix * positionWS;
     gl_Position = gProjectionMatrix * positionVS;
-    vTexcoord = aTexcoord;
+    vTexcoord = vec2(aTexcoord.x, 1.0 - aTexcoord.y);
 }
\ No newline at end of file
diff --git a/tests/RHI/OpenGL/integration/sphere/main.cpp b/tests/RHI/OpenGL/integration/sphere/main.cpp
index 36705970..22a7e6ef 100644
--- a/tests/RHI/OpenGL/integration/sphere/main.cpp
+++ b/tests/RHI/OpenGL/integration/sphere/main.cpp
@@ -24,6 +24,8 @@
 
 #pragma comment(lib, "opengl32.lib")
 
+#include <GL/gl.h>
+
 using namespace XCEngine::RHI;
 using namespace XCEngine::Debug;
 using namespace XCEngine::Containers;
@@ -65,12 +67,12 @@ void TranslationMatrix(float* m, float x, float y, float z) {
 void PerspectiveMatrix(float* m, float fov, float aspect, float nearZ, float farZ) {
     memset(m, 0, 16 * sizeof(float));
     float tanHalfFov = tanf(fov / 2.0f);
-    m[0] = 1.0f / (aspect * tanHalfFov);
-    m[5] = 1.0f / tanHalfFov;
-    m[10] = -(farZ + nearZ) / (farZ - nearZ);
-    m[11] = -1.0f;
-    m[14] = -(2.0f * farZ * nearZ) / (farZ - nearZ);
+    m[0] = 1.0f / (aspect * tanHalfFov);  // m[0][0]
+    m[5] = 1.0f / tanHalfFov;              // m[1][1]
+    m[10] = -(farZ + nearZ) / (farZ - nearZ);  // m[2][2]
+    m[14] = -(2.0f * farZ * nearZ) / (farZ - nearZ);  // m[2][3]
     m[15] = 0.0f;
+    m[11] = -1.0f;  // m[3][2] = -1 for OpenGL clip space
 }
 
 struct Vertex {
@@ -236,10 +238,16 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
     float aspect = 1280.0f / 720.0f;
     PerspectiveMatrix(projectionMatrix, 45.0f * 3.14159265f / 180.0f, aspect, 0.1f, 1000.0f);
 
-    shader.SetMat4("gModelMatrix", modelMatrix);
-    shader.SetMat4("gViewMatrix", viewMatrix);
-    shader.SetMat4("gProjectionMatrix", projectionMatrix);
-    shader.SetInt("uTexture", 0);
+    Log("[DEBUG] ProjectionMatrix:");
+    for (int i = 0; i < 4; i++) {
+        Log("[DEBUG]   row%d: %.4f %.4f %.4f %.4f", i, 
+            projectionMatrix[i*4], projectionMatrix[i*4+1], projectionMatrix[i*4+2], projectionMatrix[i*4+3]);
+    }
+    Log("[DEBUG] ModelMatrix:");
+    for (int i = 0; i < 4; i++) {
+        Log("[DEBUG]   row%d: %.4f %.4f %.4f %.4f", i,
+            modelMatrix[i*4], modelMatrix[i*4+1], modelMatrix[i*4+2], modelMatrix[i*4+3]);
+    }
 
     OpenGLPipelineState pipelineState;
     OpenGLRasterizerState rasterizerState;
@@ -247,8 +255,9 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
     pipelineState.SetRasterizerState(rasterizerState);
 
     OpenGLDepthStencilState depthStencilState;
-    depthStencilState.depthTestEnable = false;
-    depthStencilState.depthWriteEnable = false;
+    depthStencilState.depthTestEnable = true;
+    depthStencilState.depthWriteEnable = true;
+    depthStencilState.depthFunc = ComparisonFunc::Less;
     pipelineState.SetDepthStencilState(depthStencilState);
 
     ViewportState viewportState = { 0.0f, 0.0f, (float)gWidth, (float)gHeight, 0.0f, 1.0f };
@@ -257,6 +266,16 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
     pipelineState.AttachShader(shader.GetID());
     pipelineState.Apply();
 
+    Log("[DEBUG] Shader program ID: %u", shader.GetID());
+    int modelLoc = shader.GetUniformLocation("gModelMatrix");
+    int viewLoc = shader.GetUniformLocation("gViewMatrix");
+    int projLoc = shader.GetUniformLocation("gProjectionMatrix");
+    Log("[DEBUG] Uniform locations - gModelMatrix: %d, gViewMatrix: %d, gProjectionMatrix: %d", modelLoc, viewLoc, projLoc);
+    shader.SetMat4("gModelMatrix", modelMatrix);
+    shader.SetMat4("gViewMatrix", viewMatrix);
+    shader.SetMat4("gProjectionMatrix", projectionMatrix);
+    shader.SetInt("uTexture", 0);
+
     OpenGLTexture texture;
     if (!texture.LoadFromFile("Res/Image/earth.png", true)) {
         Log("[ERROR] Failed to load texture");
@@ -276,6 +295,7 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
     int frameCount = 0;
     const int targetFrameCount = 30;
 
+    int renderCount = 0;
     while (frameCount < targetFrameCount) {
         if (PeekMessageW(&msg, NULL, 0, 0, PM_REMOVE)) {
             if (msg.message == WM_QUIT) {
@@ -284,17 +304,30 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
             TranslateMessage(&msg);
             DispatchMessageW(&msg);
         } else {
+            renderCount++;
+            GLenum err = glGetError();
+            if (err != GL_NO_ERROR) Log("[DEBUG] GL error before clear: 0x%x", err);
+
             commandList.SetViewport(0, 0, gWidth, gHeight);
-            commandList.Clear(0.0f, 0.0f, 1.0f, 1.0f, 1);
+            commandList.Clear(0.0f, 0.0f, 1.0f, 1.0f, 1 | 2);  // COLOR_BUFFER | DEPTH_BUFFER
+
+            err = glGetError();
+            if (err != GL_NO_ERROR) Log("[DEBUG] GL error after clear: 0x%x", err);
 
             pipelineState.Bind();
 
+            err = glGetError();
+            if (err != GL_NO_ERROR) Log("[DEBUG] GL error after pipeline bind: 0x%x", err);
+
             indexBuffer.Bind();
             vertexArray.Bind();
 
             texture.Bind(0);
             sampler.Bind(0);
 
+            err = glGetError();
+            if (err != GL_NO_ERROR) Log("[DEBUG] GL error before draw: 0x%x", err);
+
             commandList.DrawIndexed(PrimitiveType::Triangles, (uint32_t)indices.size(), 0, 0);
 
             swapChain.Present(0, 0);
@@ -302,8 +335,15 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
         }
     }
 
+    Log("[INFO] Rendered %d frames (target was %d)", renderCount, targetFrameCount);
     Log("[INFO] Reached target frame count %d - taking screenshot!", targetFrameCount);
-    OpenGLScreenshot::Capture(device, swapChain, "sphere.ppm");
+
+    char exePath[MAX_PATH];
+    GetModuleFileNameA(NULL, exePath, MAX_PATH);
+    char* lastSlash = strrchr(exePath, '\\');
+    if (lastSlash) *lastSlash = '\0';
+    strcat_s(exePath, "\\sphere.ppm");
+    OpenGLScreenshot::Capture(device, swapChain, exePath);
 
     sampler.Shutdown();
     texture.Shutdown();